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Crumbtrail TV Forums: TV Equipment: VCR Repair Forum:
JVC HR-D190EN doens't take tape

 

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the98
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Nov 9, 2017, 12:06 PM

Post #101 of 125 (3953 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

If IC601 tells the VCR when it's on, then IC601 may be fried, right?

I think the only thing I can do now is figuring out why I'm getting 12 V when 0.1 are expected.

Do you think there's something to check on the motherboard? Do you have any schematics or something?


jts1957
Veteran


Nov 9, 2017, 5:48 PM

Post #102 of 125 (3951 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post

https://elektrotanya.com/
https://elektrotanya.com/...ek.pdf/download.html
https://elektrotanya.com/...sm.pdf/download.html


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Location: Far, Far Away


the98
User

Nov 12, 2017, 3:45 PM

Post #103 of 125 (3936 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

I desolder the wire I previously solder on CP3 and CP4. I proceed to check if I still have DVC on Pin 1 and 2 of IC601, and I do (5 V). Then check pin 6 of 601 and I get 5 V instead of 12 V.

What could be going on?


jts1957
Veteran


Nov 12, 2017, 8:14 PM

Post #104 of 125 (3934 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post


Quote
I desolder the wire I previously solder on CP3 and CP4.


If YOU are going to use one wire to jumper the 5 & 12 volt supplies together, BOTH supplies will assume the value of the higher supply. (Electrolytic capacitors and many semiconductors are apt to not tolerate.)


Quote
CP3 and CP4 are opened.

Can one assume they are now (magically) closed?


Quote
What could be going on?

The nut behind the wheel is defective.


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Location: Far, Far Away


the98
User

Nov 12, 2017, 9:58 PM

Post #105 of 125 (3930 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Let's go over what I did so there's no confusion:

1- Was to told to check CN604. Checked Pins 1 and 5, in this process, something shorted and VCR stopped turning on (display works).

CN608 is near the area of pin 1 and 5 of CN604. It's possible that I made continuity between those two. (I mentioned this to see if there is any clue that might reveal the problem).

2- When this happened, I looked for continuity in the fuses, and CPx. Found that CP3 had no continuity, as well as CP4.

3- Solder a piece of thin wire to close the circuit between both ends of CP3, and another piece of wire to close CP4. Both had continuity after that soldering, but not between them. Turn the VCR on, and no magic smoke appeared.

4- Performed all the tests you told me too, measuring DVC in different points. The weirdest result I got, in my opinion, was on Pin 6 of IC601, which was supposed to give me like 0.1 V (according to your post) and was in fact getting like 12 V.

5- So today I decided to see if desoldering both wires on CP3 and CP4, would change any voltage on IC601. Since I hadn't checked any CP before this happen, I thought that maybe they were bad from the beginning. To my surprise, pins 1 and 2 where still getting 5 V. and pin 6 was getting 5 V.

Now, correct me if I'm wrong, but I understand that CP are like fuses, so if the circuit has no continuity, it's open, and no current is going through. The circuit interrupted because of a short I made, and CP broke. Soldering a piece of wire should let the current go through the circuit. I never said I jumpered CP3 to CP4.

So, if all the events are clear, is there anything else I can checked, or should I just throw the unit away?

I really thank you for all the help you gave me so far.


jts1957
Veteran


Nov 13, 2017, 12:00 AM

Post #106 of 125 (3928 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post

ONLY the test lead tip with its extremely sharp point should be used when taking a measurement. If the metal part of the test lead between the handle and the tip/point is threatening to make contact with a undesired point, YOU have the option of continuing on and risking a accidental short, addressing the excess metal or providing an alternate way to measure. I've already given you a couple of alternate ways to take a measurement, now I see I need to address a couple of ways to cope with excess probe metal.
1) Electrical tape wrapped around tip, cut as required; 2) Shrink tubing, cut to length and positioned and shrunk onto probe; 3) Dip into fingernail polish or paint, when fully cured carefully score and expose point; 4) Insulation off a piece of wire, sized to diameter and length, then slipped over tip.

There are two ways to check a fuse or circuit protector or low value fusible resistor when used in a DC application.
1) With unit unplugged, measure OHMS across the device. IF good will read like a piece of wire - damn near zero.
2) With unit plugged in, and if is protecting a switched source, that source energized. Measure on each side of device. IF good will read the same voltage on BOTH ends, If a voltage is present on one end but not the other ... it is bad.


Quote
I desolder the wire I previously solder on CP3 and CP4.

I'll stick by YOUR statement.

IF same two are open, reconnect a jumper across EACH while monitoring voltages on those same pins on IC601. See which one or have to have both for pin 6 too high.


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Location: Far, Far Away


the98
User

Nov 14, 2017, 12:04 AM

Post #107 of 125 (3923 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Values of pin 6 of IC601 before doing anything:

0- Jumper CP3 and CP4 (not together): 12 V
00- Removed Jumpers on both: 5 V

0 and 00 were the previous results I got, which were posted before.

Today I started by:

1- Solder Jumper on CP4: 12 V
2- Desolder CP4 and solder Jumper on CP3: 0.25 V
3- Desolder both : 0.25 V

The weirdest part of this process is that, before I even started resoldering anything, I checked one more time DVC on pin 6. It was getting 5 V when CP3 and CP4 had no jumpers. Now, I get 0.25 V.


(This post was edited by the98 on Nov 14, 2017, 12:49 AM)


the98
User

Nov 26, 2017, 12:47 AM

Post #108 of 125 (3834 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

I've noticed that pin #5 of the STK5481 is getting 6.35 v.



This is happening when the Regulator Board is not plugged into the motherboard (I don't know if can affect the reading, because all of the other pins are getting the values they're supposed to get).

Trying to trace down where those 6.35 v come from, I get this:



Basically, pin 6 is outputting 12.11 v, that goes to R8, and you get the 6.35 v, that end up in pin 5.

Since, according to the first diagram, and the VCR's service manual, I should expect to get like 0.2 V, why am I getting those readings?

How should I get 0.2 V in the first place, when there's a connection there that feeds pin 5 6.35 V?

PS: D11 only reads continuity in one direction.


jts1957
Veteran


Nov 26, 2017, 2:13 AM

Post #109 of 125 (3831 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post

You forgot about the microprocessor (IC601 pin 6 via Pin 11 of CN1). Without regulator board plugged into motherboard The 'active low' Power ON/OFF (NOTE the bar above 'ON') can't be pulled down. 5V & 12V SW (pins 3 & 4) shouldn't be present either.

If all is as it should be (and no one shorts together points not meant to be connected together) ... IC601 gets VCC (via unswitched 12V, regulated to 5V by Q601); Power button (on keyboard or remote) is pushed once and pin 6 should go low (close to zero) ... pushed a second time and should go high (close to VCC; 5V).


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Location: Far, Far Away


the98
User

Nov 26, 2017, 2:50 AM

Post #110 of 125 (3828 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

I plugged every board, and pin 5 of STK measures 3.18 V. Still higher than 0.2.

As far as IC601, I'm not sure if pin 6 is responsible of powering the unit. It's a different IC than the one on both service manuals. It's possible they are equivalent, but there are also differences on the layout of the board.


the98
User

Nov 26, 2017, 8:35 PM

Post #111 of 125 (3813 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

https://i.imgur.com/rmEbte3.png

Through this picture I try to show why Pin #6 of IC601 is getting 2.77 V.

As you can see, 3.6 V come out of CN602 #1 which go to D613, and turn into 3.06 V. This goes into R634, which result in 2.77 V that go into #6 of IC601. But those 2.77 V also go to Q609 B (which is not on any service manual).

This confuses me, in the sense that I'm not sure if pin #6 of IC601 is supposed to be getting 0.2 V,or what the real value is supposed to be. If you're sure that it is supposed to get 0.2 v, then I should try to figure out why is getting 2.77 V.

As for IC601, part number is: M50731-613SP. I couldn't find any datasheet, or any other info online.


jts1957
Veteran


Nov 26, 2017, 9:54 PM

Post #112 of 125 (3811 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Let's add to the confusion: Float pin 6. Any DCV on the floating pin as you press the power button on, then off.


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Location: Far, Far Away


the98
User

Nov 27, 2017, 11:21 PM

Post #113 of 125 (3792 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Floating the pin is giving me like 0.15 V. I'm not sure pressing the Power button does something.

B262, which goes right into Pin#6 of IC601, is now reading like 12 V.

Do you think IC601 is ruined?


jts1957
Veteran


Nov 28, 2017, 9:59 PM

Post #114 of 125 (3774 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Not necessarily.
Although your #111 got me downloading some more VCR manuals and based on that additional info, I now realize that while the initial two manuals (one that has mechanism specifics close to yours, and the other having Power supply, Mode & basket drives similar to yours) have IC601's with very similar pinouts to each other, other models differ. NONE that I've downloaded are covering your actual IC number. Certain pins appear to be universal to part number style (M five digit dash three digit SP) VCC, VSS, for example.

Let's try working from the PS back to the micro.
Currently the SW 5V & SW 12V Do NOT come up at any time? True or false.


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Location: Far, Far Away


the98
User

Nov 28, 2017, 10:49 PM

Post #115 of 125 (3770 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

First of all, let me thank you again for all the trouble you're taking.

No SW voltage come up at point.

TP1 = 0.2 V
TP2 = 0.07 V


jts1957
Veteran


Nov 28, 2017, 11:06 PM

Post #116 of 125 (3768 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Everything connected?
Also you DO HAVE a lit display?

Take a 1,000 ohm resistor and connect one end to the junction of D11 & R8. While monitoring DCV on pin 3 and/or pin 4 of IC1, touch the other end of the 1K resistor to ground and see if either one come up.


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Location: Far, Far Away


the98
User

Dec 1, 2017, 11:05 PM

Post #117 of 125 (3712 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Display shows the clock.

Tests were made with everything connected.

Grounding that junction is giving me SW 12V, but no 5V. I get like 0.67V on TP1.


jts1957
Veteran


Dec 2, 2017, 12:18 AM

Post #118 of 125 (3699 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Check Pin 2 of IC1 for unregulated B-plus (~9-10 volts). If NOT present, check glass fuse F3 ... If present, ensure there is NO short on pin 3, then replace IC1.


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Location: Far, Far Away


the98
User

Dec 2, 2017, 1:29 AM

Post #119 of 125 (3689 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

I replaced F3 and got SW 5 V. Only power light goes on, but the VCR is not really on, since you can't operate it as if it was on. You only see the clock flashing, just as if it was off, but with power led on.

Play light, and any other than power light don't turn on (should they?)


jts1957
Veteran


Dec 2, 2017, 1:53 AM

Post #120 of 125 (3682 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post

12V & 5V - both now come up/down? Using Power button or just with grounding junction?


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Location: Far, Far Away


the98
User

Dec 2, 2017, 2:09 AM

Post #121 of 125 (3674 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

They come up with grounding junction. Power button does nothing.


jts1957
Veteran


Dec 2, 2017, 2:49 AM

Post #122 of 125 (3665 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Back to: Let's try working from the PS back to the micro. We are attempting to figure out which pin of IC601 is power ON/OFF since pin6 is NOT.

Does junction trace back to CN1 Pin11? if yes, then to CN602 Pin6? Check continuity between those two points. If connects to there, then need to trace to IC601 Pin?.


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Location: Far, Far Away


the98
User

Dec 2, 2017, 3:59 PM

Post #123 of 125 (3487 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Junction traces back to CN1 #11, which goes into CN602 #1, and that turns out to trace back to IC601 #6, as you can see on this pic previously posted:

https://i.imgur.com/rmEbte3.png

(Damn)


(This post was edited by the98 on Dec 2, 2017, 4:01 PM)


jts1957
Veteran


Dec 2, 2017, 6:05 PM

Post #124 of 125 (3460 views)
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Re: [the98] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Did we ever get around to grounding Pin 6 of IC601 while monitoring SW5V & SW12V? (Through a 1K resistor)


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Location: Far, Far Away


the98
User

Dec 2, 2017, 7:49 PM

Post #125 of 125 (3434 views)
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Re: [jts1957] JVC HR-D190EN doens't take tape [In reply to] Can't Post

Just done that. Got both voltages.

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