Fisher VCR Model FVH-720 (very old) No Power


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Fisher VCR Model FVH-720 (very old) No Power

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Bandit
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May 15, 2010, 5:21 AM

Post #1 of 41 (13279 views)
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Fisher VCR Model FVH-720 (very old) No Power	Can't Post

Hello Everyone,
I attempted to load a VHS tape that had sentimental home movies. When I inserted the VHS tape, it jammed in the front load mechanism making lots of motor noise. Couldn't get it out. I unpluged the unit. Took the top cover off, then I manually turned the the motor pulley which eventually released the tape. When I re-pluged the unit, it would not power on. The LED display flashes but nothing else works. There are 2 fuses which I checked. They look fine. I don't think there is a short, but there must be a reason why the unit will not power up. Any suggestions?
Thank you !!
The Bandit

techchris
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May 15, 2010, 8:35 AM

Post #2 of 41 (13276 views)
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Re: [Bandit] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

if the mechanism is out of alignment then it will not work or load a tape.When it jammed something may have broken off the mechanism, usually a plastic part. you will need the service manual to realign the mechanism as there are notches or marker arrows on the gear wheels to align it in the correct order. Probably cheaper to buy a new cheap vcr online than trying to fix that one.

Bandit
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May 15, 2010, 5:06 PM

Post #3 of 41 (13275 views)
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Re: [techchris] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

I have removed the front loading mechanism & visually checked it. Lots of gears on it, but nothing is broken or missing that I can see. There are no "notches or markers" on any of the gears on the front loading carriage mechanism. I am not familiar with the part names but I know what they look like. The only place where there are "notches or marker arrows" are underneath the unit and not on the loading mechanism. Here, I do see one large gear with 3 raised markers . Next to it a smaller gear with an arrow. I think this is wear the alignment you speak of is adjusted. Doesn't seem that difficult a task as there can only be 3 possible combinations which I have tried. Unit still wont power up.
Could there be a switch or something else linvolved?
If it is a simple alignment, seems a waste to throw the unit away!!
Thanks for any further suggestions.
The Bandit

jts1957
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May 15, 2010, 9:13 PM

Post #4 of 41 (13273 views)
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Re: [Bandit] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Quote

There are 2 fuses which I checked. They look fine.

Once you get below 5 Amps, the wires inside glass fuses become very hard to tell if good with the naked eye.

I'd check them out of the unit with an DVM or other continuity tester.

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Location: Far, Far Away

Bandit
New User

May 16, 2010, 6:24 PM

Post #5 of 41 (13268 views)
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Re: [jts1957] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Took your advise and tested fuses with continuity tester. They test fine. To play safe, I installed 2 new fuses of the same exact type as well. Unit still wont power up. Led display flashes but that's it. Anymore suggestions would be greatly appreciated !!
Thanks,
The Bandit

jts1957
Veteran

May 16, 2010, 6:35 PM

Post #6 of 41 (13266 views)
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Re: [Bandit] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Check STK5431 in power supply. Wink

Also check/replace C918. Smile

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Location: Far, Far Away

(This post was edited by jts1957 on May 16, 2010, 6:49 PM)

Bandit
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May 18, 2010, 5:11 PM

Post #7 of 41 (13259 views)
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Re: [jts1957] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

I have removed the Power Supply. There are TWO boards identified as PCB-A and PCB-B. On PCB-B, there is a cap identified as C918. However, there is nothing on either boards identifying STK5431. Anyway, I have removed C918 and gave it to a friend that has an ESR meter and he tested it & told me that the cap was good !! Are you looking at a schematic? I cant seem to find STK5431. At this point I am starting to lean toward TechChris suggestion that the unit is misaligned and there is a sequential order procedure in aligning the unit that I have missed. Would appreciate your imput.

Thanks,
The Bandit

(This post was edited by Bandit on May 18, 2010, 5:16 PM)

jts1957
Veteran

May 18, 2010, 11:43 PM

Post #8 of 41 (13250 views)
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Re: [Bandit] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Bear in mind that I am NOT saying the parts I mentioned ARE bad. I am saying that they should be checked, and therefor ruled out.

STK5431 is the TYPE number on an IC in the power supply. I can't recall the LOCATION number. Here is the datasheet: http://www.datasheet.org.uk/search.php?q=stk5431

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Location: Far, Far Away

Bandit
New User

May 19, 2010, 4:07 AM

Post #9 of 41 (13243 views)
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Re: [jts1957] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Jts,
Still can't find STK5431 on power supply. Since I don't have the service manual, today, I kept thinking of TechChris suggestion that the unit won't power up to play if it is out of alignment. I tried a few more times, & discovered I missed something and finally it powered up. Sort of complicated for me to describe since I am not a technician & do not know the names for the specific parts. Suffice it to say, now I got power !!
However, now there is a secondary problem. The front loading mechanism will NOT load a cassette all the way. I have to press down on the cassette, otherwise it ejects the cassette in about 5 seconds. Once I press down on the cassette with my hand, it works fine. Then I hit the play button and it works fine too. If I lift the front loading carriage mechanism out of the unit, and insert a cassette, it loads smoothly with no problem. What can be causing this? Could it be obstructed by something? I have checked the gears & springs on the loading mechanism. They look fine. The belt also looks fine. The unit has 2 belts which I replaced 3 months ago.
I think I am almost there. Any further suggestions would greatly be appreciated!! Wink

Thanks,
The Bandit

(This post was edited by Bandit on May 19, 2010, 4:15 AM)

jts1957
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May 19, 2010, 5:01 AM

Post #10 of 41 (13238 views)
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Re: [Bandit] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

As Ronald Reagan used to say "I Forget." I USED to have the SM too.
Which type of carriage is it? I presume front load. Crazy

Motor on the carriage drive; Motor on the deck drives pulley on carriage via belt; or a gear on deck drives a gear on the carriage?

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Location: Far, Far Away

Bandit
New User

May 19, 2010, 4:36 PM

Post #11 of 41 (13234 views)
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Re: [jts1957] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Quote:
"Which type of carriage is it? I presume front load. Crazy

Motor on the carriage drive; Motor on the deck drives pulley on carriage via belt; or a gear on deck drives a gear on the carriage? "
WHAT ARE YOU TALKING ABOUT????? As I said before, I am not familiar with all the part names. I did say in most of my posts that the unit is front load. There are two motors on the unit. One motor (having the longer belt) that is located on the upper right corner of the so called "carriage" moves the gears for the cassette to go IN & DOWN when loading, and UP & OUT when ejecting. The other motor has a smaller belt & is NOT on the so called "carriage". I am not sure of it's function.
Thanks,
The Bandit

(This post was edited by Bandit on May 20, 2010, 5:52 PM)

Barry777
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May 21, 2010, 1:23 PM

Post #12 of 41 (13221 views)
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Re: [Bandit] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Bandit,
I think the other poster is trying to find out whether your tape carriage is fully self-contained (belt, motor and pulley) or is driven by other stuff on the deck (gear). First thing I would do is make sure that there is no belt slippage - especially on the tiny small belts which are responsible for loading/unloading tapes, and aligning the mechanism for the various functions. Your problem sounds an awful lot like a mechanism that is not fully cycling due to slipping belts.

I usually place a finger (or any hard object that will make a little noise) on the motor PULLEY. This makes it easy to see if there is any motor rotation after the mechanism appears to reach the end of a cycle. If the motor is still turning but not driving any other pulleys (spinning under the belt), you just found the problem - something needs lubrication and possibly disassembly/cleaning. This is the most common problem I see with older VCR's.

With older VCR's, always fully exhaust mechanical possibilities before rooting around in the electronics. And if you do make it to the electronics, always replace all electrolytic caps in the power supply before going any further, as dirty power will wreak havoc in these sensitive circuits.
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Barry Fone - VCR Repair hobbyist and professional FAA Repair Station Avionics Bench Technician (top level). TEST EQUIPMENT: (4) Sencore VC93 VCR Analyzers, (11) Tentel gauges, Sencore VA48 and (2) VA62 Video Analyzers, Sigma Electronics TSG-375 NTSC/SMPTE Video Generator, several VCR Alignment Tapes, plus countless Oscilloscopes, Frequency Counters, Wow and Flutter Meters, Distortion Analyzers, Vectorscope, 136-channel Logic Analyzer, Signature Analyzer . . . . VIDEO GEAR: (6) JVC BR-S822U's, (3) JVC BR-7000 series, (3) JVC BR-S500U, (2) JVC BR-S800U, JVC GR-800U and (2) GR-860U Editing Controllers, Sony FXE-100 Video Switcher/Effects Generator, (5) Time Code Generator/Readers, (1) Sony SLO-1800 (Beta), (2) Alesis ADAT-XT, (1) Sony DXC-1200 TV Camera, Pioneer VP-1000 Laser Disc Player plus many consumer grade Beta and VHS VCR's. Passionate electronics enthusiast since 1973...most anything except computers. Check out my collection at www.barrys8trackrepair.com/MyVideoGear.html

Bandit
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May 21, 2010, 11:52 PM

Post #13 of 41 (13220 views)
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Re: [Barry777] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Quote:
"Your problem sounds an awful lot like a mechanism that is not fully cycling due to slipping belts.
I usually place a finger (or any hard object that will make a little noise) on the motor PULLEY. This makes it easy to see if there is any motor rotation after the mechanism appears to reach the end of a cycle. If the motor is still turning but not driving any other pulleys (spinning under the belt), you just found the problem - something needs lubrication and possibly disassembly/cleaning. This is the most common problem I see with older VCR's."

Bingo !! This is EXACTLY what is happening. Motor belt on carriage slipping. Yes, the cassette tape carriage is self contained as you describe it, i.e. belt, motor and pulley. The pulley turns the gears on the carriage. If I remove the carriage out of the unit, there is no slippage. Only happens when the carriage is in the unit. PLEASE TELL ME WHAT LUBRICANT TO USE ON WHAT PARTS & WHAT PARTS TO CLEAN? SHOULD I REPLACE THE BELT AS WELL?
Thank you so very much for diagnosing this for me!! You've solved the problem!! YAY !!!
The Bandit

Barry777
User

May 22, 2010, 2:01 PM

Post #14 of 41 (13216 views)
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Re: [Bandit] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

It's about time I did some good in here! I've been a technician since 1973, and I STILL have this bad habit of going straight to the complicated stuff and overlooking the real problem (like most of the guys in here). So your carriage is not able to complete its own cycle, thus causing your VCR to think there's no tape in the unit and, in turn, no reason to go into the play, FF or REW cycles.

I would definitely replace the belt - but if it still has tension and some grip, you can probably get away with cleaning the belt with rubber conditioner and cleaning the pulleys with alcohol. Regular household isopropyl alcohol will work fine, though industrial grade (99%) alcohol (or even Ever Clear) will do a slightly better job. You'll also want to think about what else that motor may be trying to drive when the carriage is in the unit, and take appropriate measures to reduce friction there too. Sometimes I boil belts for a few minutes to restore some of the softness and grip - just stay at the stove and use a fork to make sure the belt never contacts the sides or bottom of the pan which will melt it.

Lithium grease is a great VCR lubricant, and you can get belts and rubber cleaner from MCM Electronics (www.mcmelectronics.com). Another good place is Studio Sound Electronics who have recently added a cross reference service to their website. If you tell them the model of your VCR and which belt you need, they can probably send you very close to an exact replacement.

Good luck, glad I was able to help!
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Barry Fone - VCR Repair hobbyist and professional FAA Repair Station Avionics Bench Technician (top level). TEST EQUIPMENT: (4) Sencore VC93 VCR Analyzers, (11) Tentel gauges, Sencore VA48 and (2) VA62 Video Analyzers, Sigma Electronics TSG-375 NTSC/SMPTE Video Generator, several VCR Alignment Tapes, plus countless Oscilloscopes, Frequency Counters, Wow and Flutter Meters, Distortion Analyzers, Vectorscope, 136-channel Logic Analyzer, Signature Analyzer . . . . VIDEO GEAR: (6) JVC BR-S822U's, (3) JVC BR-7000 series, (3) JVC BR-S500U, (2) JVC BR-S800U, JVC GR-800U and (2) GR-860U Editing Controllers, Sony FXE-100 Video Switcher/Effects Generator, (5) Time Code Generator/Readers, (1) Sony SLO-1800 (Beta), (2) Alesis ADAT-XT, (1) Sony DXC-1200 TV Camera, Pioneer VP-1000 Laser Disc Player plus many consumer grade Beta and VHS VCR's. Passionate electronics enthusiast since 1973...most anything except computers. Check out my collection at www.barrys8trackrepair.com/MyVideoGear.html

Bandit
New User

May 25, 2010, 7:50 PM

Post #15 of 41 (13202 views)
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Re: [Barry777] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Barry,
YOU ARE THE MAN !!! The belts still had some grip in them. I Took your advice on boiling the belts, and then cleaning the pulleys with household alcohol. I also used a dab of lithium grease where needed. Everything now works beautifully. Rewind, fast forward, play and most of all the cassette carriage works great. No slippage. I have written down the two sites for parts in case over time I need to replace the belts.
I wanted to personally thank you for solving my problem, and FOR ALL YOU DO IT YOUSELVERS, IF YOU WANT IT DONE RIGHT, BARRY IS THE MAN !!!
The Bandit
P.S. Know any good sites for VCR Service manuals?

Barry777
User

May 26, 2010, 1:57 AM

Post #16 of 41 (13199 views)
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Re: [Bandit] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Thanks for your kind comments, Bandit. My real "claim to fame" was being the top dawg of 8 track repair (Barry's 8 Track Repair) which I shut down for awhile to rekindle my passion for VCR's and just play around with stuff. I did a lot of VCR work in the 80's when they were the big thing, and before they turned into these 5 pound plastic pieces of junk. On the service manual issue , ManualUniverse.com or ServiceManuals.net are great websites. You can download and print your manual mere moments after paying online with a credit card. These two are safe; I had tried another one that ended up funneling 60 bucks of my money to some place in Moscow, but I called my bank and had the transaction cancelled. You'll generally pay between 15 and 25 bucks for a service manual download. The schematics are not usually crisp and clear and sometimes the edges are off the page, but so far I've always been able to muddle through them and get the stuff fixed.

I mostly work on JVC professional machines these days, those huge 50 pound monsters with all the cool meters, buttons and functions I'll never learn how to use. I was once a professional musician and want to record myself on video one last time before I hang up the guitar for good. My plan is to eventually sync up at least 2 recording VCR's (for 2 camera angles) with my ADAT (Alesis Digital Audio Tape) machines for 24 track audio, and produce as close to a professional video production as possible to make my friends think I got somewhere in music! It's been a several month project so far, learning how to use the needed time code equipment to synchronize video with audio, as there are 3 or 4 different time code languages, then it must be converted to a format that the ADAT machines can understand. As I'm by no means an experienced videographer, it's been quite a learning process.

The idler tire on the Fisher FVH series is one of the more difficult ones to replace, especially if the chassis doesn't have that little half-round cutout to enable you to extract the idler assembly. It's easier if you remove the takeup reel first, but you can just jam the idler aginst the reel and only make a small and harmless flat spot on the plastic idler wheel (the cutout is a bit too close to the takeup reel). You have to peel back the tire with the idler still in the unit, in order to get it close enough to the cutout to extract it. On most older Fishers, the idler tire is very thin - smaller, in fact, than a loading belt - and wears out pretty quickly or glazes over.

If your chassis doesn't have the half-round cutout and the idler assembly seems hopelessly buried in the mechanism - well, it IS! The early Fisher front loaders were not exactly designed with serviceability in mind. But instead of taking the whole darn thing apart and hassling with getting the gears back in alignment, here's a trick that will save you hours of frustration and grief: Get one of those nibbling tools from Radio Shack, and just cut away enough steel to get that rascal out of there! Having spent many years in Heating and Cooling, I always have tin snips around, but they bend the metal too much at the angle you need to cut. I never tried the nibbling tool, but I'm sure it works much better.

Many shops wouldn't even take in Fishers for this very reason - they're too professional-minded and don't know how to Afro-engineer solutions. Replacing the idler tire the "correct" way is a ridiculous waste of time and sanity, requiring you to take the mechanism completely apart. I've never seen the service manual, but they frequently take you the long way around doing things too, when there's a much easier way with fewer steps. Generally, you follow the manual the first time, then do it your own more efficient way after that. Just like when a car manual says to remove the spark plugs when replacing the timing belt, presumably to eliminate any chance of the engine starting and messing up the crank-to-camshaft relationship. Geez, just make sure no one's in the driver seat with the key!

Good luck and thanks again - let me know if you need any more advice.
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Barry Fone - VCR Repair hobbyist and professional FAA Repair Station Avionics Bench Technician (top level). TEST EQUIPMENT: (4) Sencore VC93 VCR Analyzers, (11) Tentel gauges, Sencore VA48 and (2) VA62 Video Analyzers, Sigma Electronics TSG-375 NTSC/SMPTE Video Generator, several VCR Alignment Tapes, plus countless Oscilloscopes, Frequency Counters, Wow and Flutter Meters, Distortion Analyzers, Vectorscope, 136-channel Logic Analyzer, Signature Analyzer . . . . VIDEO GEAR: (6) JVC BR-S822U's, (3) JVC BR-7000 series, (3) JVC BR-S500U, (2) JVC BR-S800U, JVC GR-800U and (2) GR-860U Editing Controllers, Sony FXE-100 Video Switcher/Effects Generator, (5) Time Code Generator/Readers, (1) Sony SLO-1800 (Beta), (2) Alesis ADAT-XT, (1) Sony DXC-1200 TV Camera, Pioneer VP-1000 Laser Disc Player plus many consumer grade Beta and VHS VCR's. Passionate electronics enthusiast since 1973...most anything except computers. Check out my collection at www.barrys8trackrepair.com/MyVideoGear.html

(This post was edited by Barry777 on May 26, 2010, 2:08 AM)

jts1957
Veteran

May 26, 2010, 8:31 AM

Post #17 of 41 (13191 views)
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Re: [Barry777] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

I seem to recall a toothed gear idler assembly was used for "Play/Record," and "Forward & Reverse Search."

The rubber tired idler was for regular "Fast Forward/Rewind."

I forget which was used to pull the tape back into the cassette before it was Ejected.

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Location: Far, Far Away

Barry777
User

May 26, 2010, 1:24 PM

Post #18 of 41 (13188 views)
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Re: [jts1957] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Sounds good to me, jts. I haven't seen the inside of a Fisher since probably 1985, and only remember them because so many FVH's came into my shop. At first I thought, "Well, older models had the tire and newer ones had the gear, but none had both". Then it occurred to me that the assembly with the gear has the required pulley for the drive belt to fit onto, so now I'm curious. Maybe Bandit can shed some light on this, since he has a machine to look at. Most of my machines here are direct drive and I don't mess with idlers much anymore, except for my ADAT machines which have super-easy Sharp mechanisms.
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Barry Fone - VCR Repair hobbyist and professional FAA Repair Station Avionics Bench Technician (top level). TEST EQUIPMENT: (4) Sencore VC93 VCR Analyzers, (11) Tentel gauges, Sencore VA48 and (2) VA62 Video Analyzers, Sigma Electronics TSG-375 NTSC/SMPTE Video Generator, several VCR Alignment Tapes, plus countless Oscilloscopes, Frequency Counters, Wow and Flutter Meters, Distortion Analyzers, Vectorscope, 136-channel Logic Analyzer, Signature Analyzer . . . . VIDEO GEAR: (6) JVC BR-S822U's, (3) JVC BR-7000 series, (3) JVC BR-S500U, (2) JVC BR-S800U, JVC GR-800U and (2) GR-860U Editing Controllers, Sony FXE-100 Video Switcher/Effects Generator, (5) Time Code Generator/Readers, (1) Sony SLO-1800 (Beta), (2) Alesis ADAT-XT, (1) Sony DXC-1200 TV Camera, Pioneer VP-1000 Laser Disc Player plus many consumer grade Beta and VHS VCR's. Passionate electronics enthusiast since 1973...most anything except computers. Check out my collection at www.barrys8trackrepair.com/MyVideoGear.html

(This post was edited by Barry777 on May 26, 2010, 1:30 PM)

jts1957
Veteran

May 26, 2010, 2:51 PM

Post #19 of 41 (13185 views)
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Re: [Barry777] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

You had to remove the assembly with the pulley to gain access to the rubber idler.
The rubber tire's surface would press against round white piece opposite belt pulley (top of picture). Remember the spring you had to remove through the top of the cassette basket? Wink

-------------------------
Location: Far, Far Away

Barry777
User

May 26, 2010, 11:51 PM

Post #20 of 41 (13180 views)
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Re: [jts1957] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

I think you have it nailed, jts. So, where is the water pump if you know so much - hmmm?
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Barry Fone - VCR Repair hobbyist and professional FAA Repair Station Avionics Bench Technician (top level). TEST EQUIPMENT: (4) Sencore VC93 VCR Analyzers, (11) Tentel gauges, Sencore VA48 and (2) VA62 Video Analyzers, Sigma Electronics TSG-375 NTSC/SMPTE Video Generator, several VCR Alignment Tapes, plus countless Oscilloscopes, Frequency Counters, Wow and Flutter Meters, Distortion Analyzers, Vectorscope, 136-channel Logic Analyzer, Signature Analyzer . . . . VIDEO GEAR: (6) JVC BR-S822U's, (3) JVC BR-7000 series, (3) JVC BR-S500U, (2) JVC BR-S800U, JVC GR-800U and (2) GR-860U Editing Controllers, Sony FXE-100 Video Switcher/Effects Generator, (5) Time Code Generator/Readers, (1) Sony SLO-1800 (Beta), (2) Alesis ADAT-XT, (1) Sony DXC-1200 TV Camera, Pioneer VP-1000 Laser Disc Player plus many consumer grade Beta and VHS VCR's. Passionate electronics enthusiast since 1973...most anything except computers. Check out my collection at www.barrys8trackrepair.com/MyVideoGear.html

Bandit
New User

Jun 1, 2010, 3:42 AM

Post #21 of 41 (13161 views)
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Re: [jts1957] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

JTS,
The photos you've attached are accurate and as a matter of fact you do have to remove the assembly with the pulley to gain access to the idler which has a rubber tire. That rubber tire doesn't last very long!! If you're lucky maybe 25 cassettes rewinding and fast forwarding before it starts to fail. They cost less than a buck & I have about 6 on hand. Also, on fisher FVH 720 it's not that hard to remove for the manufacturer took this into account. However, on the FHV 721 that isn't the case. It's a real pain !!
Just thought I'd let you know.
The Bandit

P.S. BTW, I found the infamous STK5431 (voltage regulator) in the FHV-721 model which is located on the power supply. I still can't find it on the FHV-720 model.

(This post was edited by Bandit on Jun 1, 2010, 5:53 AM)

Bandit
New User

Jun 1, 2010, 5:37 AM

Post #22 of 41 (13160 views)
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Re: [Barry777] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Barry,
I hope you're not going to mind me imposing to ask you for more help. This time it concerns a different VCR that I keep in my bedroom along side my DVD player. Yes, it's another FISHER !! MODEL FHV-721. This model is similar to the FVH-720 in mechanical components, motors and switches. However, the Circuit Boards & electronics are different. A few days ago, I thought I'd change the belts on this unit which I did ever so carefully, noting the timing marks on the deck main gears. Getting to the idler was a nightmare to swap out that tire because in this model you have to remove what I think is referred to as the capstan motor, & a metal plate from under the deck because it dosen't have that rounded cut out that you mention. All the other belts were pretty much the same as the FVH-720 & easy to swap out. Anyway, after changing the required belts, I plugged the unit in, and the power button light came on for 5 seconds and then went off. I have re-checked the timing procedure and I believe that it is correct. There are only "X" amount of combinations which I have exhausted and re-checked. Usually, when you plug the unit in, the load motor that turns the main gear would reset itself. Not the case now, in fact the load motor isn't functioning at all. All other motors work good. I deduce with my limited knowledge that at least one of the following possibilities is causing the unit to not power on correctly:
1). Timing is off again. (I rule this out because I've re-checked it a 1/2 dozen times, or did I miss something?)

2). The loading motor is dead or no power to it. (I don't know how to test it, but I know the clutch works because I felt it click.)

3). An IC has gone bad. (Could be IC503 which supposedly is related to sending power to all the motors.This IC has 42 pins.)

4). CPU is dead or out of whack. (I doubt this because un-plugging and re-plugging should reset it)

5). Mode switch is bad. (It's the same part # as in the FVH-720 model. I rule this out because I temporarily took the one out of the working FVH-720 model & installed it on the FHV-721 model.)

6). Power supply issue. (Can't say for sure. Don't know what dirty power is all about. I temporarily rule this out, see footenote below.)

As a footnote and as crazy as this is going to sound, on 3 or 4 occasions I gave the loading motor a little gentle persuasion by manually turning the pulley which slightly moved the MODE SWITCH and the power light stayed on and allowed me to insert a cassette which the carriage took in and down smoothly. When I hit the play button, the capstan motor spins but the load motor doesn't, and thus the main gear also won't move. Then 10 seconds later, the power button light shuts off.

You did say, first rule out the mechanical before before getting into the electronics. Do you think this is an electronic or still a mechanical problem? I come here because I value the expertise of people like you & jts. I am an amateur hobbyist of sorts. I know I can buy a used unit for just a few dollars. However, I enjoy a challenge and before I decide to toss it, I want the satisfaction of least knowing, or if possible fixing it, which I must confess gives me a sense of accomplishment.

Thank you all for your time, patience and knowledge that you share with me !! Also please be patient with the names & terms I use to describe component parts.

The Bandit

P.S. BTW Barry, the project that you are working on sounds most impressive !! Might as well tell you that I come from a family of musicians. One of which was very accomplished. A composer and teacher. Unfortuantely, I did not take after them.

(This post was edited by Bandit on Jun 1, 2010, 5:42 AM)

Barry777
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Jun 1, 2010, 6:30 AM

Post #23 of 41 (13155 views)
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Re: [Bandit] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Hi Bandit,

No imposition at all, but JTS might have more experience and knowledge in this matter. Since I was repairing TV's and VCR's for a living back in the 80's, I always went for the quickest way to get the unit operating reliably - which meant cutting my own arc in that deck plate and not messing with realigning the gears and such. This enabled me to change the tire in about 15 minutes, leaving the rest of the hour for testing and reassembly (in the professional consumer repair industry, one hour is typical for most routine repairs). If the 721 was working before you took it apart, that definitely points to something not going back in the right place mechanically. I'm not familiar with the inner guts of that mechanism, but there might be a lever or spring that wasn't put back in the right position. Also, that weird large round gear with the little channel cut into it that a peg sticks into - it's very easy to get the peg in the wrong part of the channel, as two parts of the channel are usually visible no matter what position the gear is in.

The service manual for the unit would tell you a lot about its operation, and are just plain fun to read in general. At this point, a written description might not be much help - I like pictures! It sounds like you have enough knowledge to gain quite a bit from the service manual - I doubt that there is anything wrong in the circuits, especially if the unit was doing more before you replaced the belts and tire.

Good luck - we'll see what JTS has to say.
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Barry Fone - VCR Repair hobbyist and professional FAA Repair Station Avionics Bench Technician (top level). TEST EQUIPMENT: (4) Sencore VC93 VCR Analyzers, (11) Tentel gauges, Sencore VA48 and (2) VA62 Video Analyzers, Sigma Electronics TSG-375 NTSC/SMPTE Video Generator, several VCR Alignment Tapes, plus countless Oscilloscopes, Frequency Counters, Wow and Flutter Meters, Distortion Analyzers, Vectorscope, 136-channel Logic Analyzer, Signature Analyzer . . . . VIDEO GEAR: (6) JVC BR-S822U's, (3) JVC BR-7000 series, (3) JVC BR-S500U, (2) JVC BR-S800U, JVC GR-800U and (2) GR-860U Editing Controllers, Sony FXE-100 Video Switcher/Effects Generator, (5) Time Code Generator/Readers, (1) Sony SLO-1800 (Beta), (2) Alesis ADAT-XT, (1) Sony DXC-1200 TV Camera, Pioneer VP-1000 Laser Disc Player plus many consumer grade Beta and VHS VCR's. Passionate electronics enthusiast since 1973...most anything except computers. Check out my collection at www.barrys8trackrepair.com/MyVideoGear.html

Barry777
User

Jun 1, 2010, 12:21 PM

Post #24 of 41 (13153 views)
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Re: [Barry777] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Just an afterthought on substituting parts from one unit to another: I've found it more conclusive to try the suspect part (mode switch in this case) in the known good unit, rather than try the known good part in the bad unit. The reason is simple: If the known good unit keeps working, you know the suspect part is probably good, or bad if the unit now won't work. But if you try any parts in the bad unit, you can't be 100% sure there isn't more than one problem if the unit still won't work. It's splitting hairs I know, but a smidgen more conclusive. Just something I've learned from the experience of repairing several units per day over the years.

I admire your tenacity. Swapping parts between units is a huge pain in the butt as you know. I would have given up by now, at least on a consumer machine.
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Barry Fone - VCR Repair hobbyist and professional FAA Repair Station Avionics Bench Technician (top level). TEST EQUIPMENT: (4) Sencore VC93 VCR Analyzers, (11) Tentel gauges, Sencore VA48 and (2) VA62 Video Analyzers, Sigma Electronics TSG-375 NTSC/SMPTE Video Generator, several VCR Alignment Tapes, plus countless Oscilloscopes, Frequency Counters, Wow and Flutter Meters, Distortion Analyzers, Vectorscope, 136-channel Logic Analyzer, Signature Analyzer . . . . VIDEO GEAR: (6) JVC BR-S822U's, (3) JVC BR-7000 series, (3) JVC BR-S500U, (2) JVC BR-S800U, JVC GR-800U and (2) GR-860U Editing Controllers, Sony FXE-100 Video Switcher/Effects Generator, (5) Time Code Generator/Readers, (1) Sony SLO-1800 (Beta), (2) Alesis ADAT-XT, (1) Sony DXC-1200 TV Camera, Pioneer VP-1000 Laser Disc Player plus many consumer grade Beta and VHS VCR's. Passionate electronics enthusiast since 1973...most anything except computers. Check out my collection at www.barrys8trackrepair.com/MyVideoGear.html

Bandit
New User

Jun 2, 2010, 5:15 PM

Post #25 of 41 (13145 views)
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Re: [Barry777] Fisher VCR Model FVH-720 (very old) No Power [In reply to]	Can't Post

Barry,
I never did give that a try. Sounds logical. However, it worries me because maybe I end up messing up the good unit again. Maybe, I'll just try the MODE switch and the LOAD motor from the bad unit to the good unit. Hopefully, it wont do any harm. It'll be a big pain in the butt to do. Wish I knew how to test them in lieu of doing that. My thought on the timing issue is that I doubt there is any difference between the FVH-720 & the FHV-721. I did get it right on the FVH-720. I followed the same procedure. Well, if that doesn't work out, time to buy the service manual. I did a preliminary on line search for that particular model for around $50. Seems a bit over priced for almost obsolete equipment. Oh well, I'll look around & try a few more options. After that, nothing else with my limited experience to do, but to wave the white flag of defeat on this VCR. Either way, I'll post it here.
Thanks for everything.
The Bandit

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