another PTK195 RCA 61" convergence problem


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another PTK195 RCA 61" convergence problem

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Misfire
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Oct 10, 2014, 5:09 PM

Post #1 of 48 (9842 views)
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another PTK195 RCA 61" convergence problem	Can't Post

Hey guy's, new here so take it easy on me. I have a 61" RCA P61937 that my ex left when leaving,,, cause it doesn't work right, Not that I watch a lot of TV, just a spite thing to piss her off, lol. Sense starting this little project, I never knew just how complex these things are with the liquid cooling and so on. And being a Mercedes Benz Master Tech for 16 yrs, nothing elec scares me.
This is what I have, the typical 3D ghosting and no convergence adjustment in menu, From online looking around and self advice from that, this is what I have done so far,,,, replaced the STK730-130 on the hanging board, That brought the convergence menu back for about minute then disappeared again, I found the red projector diaphragm had leaked coolant on the board under it and smoked it, replaced it with a ebay one but to no avail.
What do I need to check voltage wise on this thing?? I do not know the terminology of TV things, so please work with me, It's really a big ass TV and hate to lose it especially after reading so much on how many people love these things, Thanks John.

Ron.M
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Oct 10, 2014, 7:25 PM

Post #2 of 48 (9825 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Misfire;...

I can not find a free service manual for that model number...

RCA engineers were apparently on LSD when they came out with the CTC169 & PTK 195 chassis....
There were a LOT of versions of each...
I did find a possible source online , but I NEED the FULL chassis number...
There should be some letters after PTK195xxx...
Please post the FULL number & I'll see what I can do...
I suspect that the power supply MAY be the problem...
Do you have a Digital Volt Meter or a meter that will read volts???
& DO you know how to use one ???

Later..Ron.M... Cool

...
Veteran & Retired TV technician

Misfire
User

Oct 10, 2014, 7:48 PM

Post #3 of 48 (9818 views)
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Re: [Ron.M] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Hey Ron, thanks for chiming in, Yessir, I do have a meter and I have been taught DC elec from aviation maintenance school, and from years as Mercedes tech, I know DC.
Product date Oct 2001
Service #,P61937YX1
model, P61937
serial #, 140251420
chassi #, PTK195M2T
and it was assem in Mexico, lol

Ron.M
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Oct 11, 2014, 12:57 AM

Post #4 of 48 (9794 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Misfire;...

Once again I went round & round & round trying to find a free service manual for that TV !!!
NO "F'ing" luck !!!
So , lets try this...

Can you take & post pix ???
IF so , I'd like to see a GOOD , IN-FOCUS pix of the board you replaced the STK IC on & the convergence board output transistors on it...
The board you replaced the STK on is the power supply board...
On the board is only ONE connector that has about 14 wires on it...
Follow that wiring to the only board it goes to...
That is the convergence board..
Pix , please... Smile

..IF you can...

Later...Ron.M... Cool

..
Veteran & Retired TV technician

jts1957
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Oct 11, 2014, 12:18 PM

Post #5 of 48 (9785 views)
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Re: [Ron.M] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Two connectors: One two pin for AC in (J19700) & One 6 pin for Output (J19701)

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

Ron.M
Veteran

Oct 11, 2014, 5:39 PM

Post #6 of 48 (9773 views)
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Re: [jts1957] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

jts1957;....

Thanks for the correction... Wink

...
Bear in mind that I said;=>..

Quote

I can not find a free service manual for that model number...

(OR Chassis)..
I also have several PTK195 service manuals , NONE of which have the STK730-130 power supply schematic...
So , I took a shot at what may be a similar board...
Shot went WAAYY wide... Unsure

..

Do you , by any chance , have either the schematic/service manual for that set OR the STK730-130 power supply that you'd be willing to share ???

Misfire;....
Even with the FULL model & chassis numbers , I STILL could not find a FREE service manual....
I did locate a site that MAY have a manual , but they want $25.00 for it & there's NO guarantee that it will be the right manual...

Have a GREAT weekend... Smile

..

Later..Ron.M... Cool

..
Veteran & Retired TV technician

(This post was edited by Ron.M on Oct 11, 2014, 5:48 PM)

Ron.M
Veteran

Oct 11, 2014, 11:14 PM

Post #7 of 48 (9761 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Misfire;.....

NO need to post pix....
jts1957 was kind & gracious enough to point me to a service manual that should work for us....
IF you are still willing to proceed , let us know by posting & I/we (jts1957 & I , maybe) will give you instructions as to what's next...

Thanks... Smile

...

Later..Ron.M... Cool

...
Veteran & Retired TV technician

Misfire
User

Oct 12, 2014, 6:20 AM

Post #8 of 48 (9753 views)
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Re: [Ron.M] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Hey, that's great Ron, I have read where you and the other fellow with the cat eyes have helped a lot of people and thanks for all of your help, and yessir,,show me what you got Tongue

Ron.M
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Oct 12, 2014, 5:39 PM

Post #9 of 48 (9738 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Misfire;....

On the power supply board there are 2 connectors...
One has 2 heavy wires that go to AC input (110 VAC)..
The other has 6 wires (As jts1957 pointed out)...
Use CARE when you do the following as the AC CAN be fatal...
STAY AWAY from that area...
Across from the AC connector is J19701...
Look on the board for a mark or number (s) 1 ...
Using you volt meter connect the "-" to chassis ground...
A good place for that is the tuner cover or cable connector...
You will be reading "-" DC voltages from pins 1 , 2 , & "+" voltages from pins 4 , 5 & 6...
Set the board in a SAFE way so you can take those readings with the TV turned on & the convergence screwed up..
Pin 3 is ground , so you should get "0.0" vdc there...
The pin connections on J19701 are apt to be small & close together..
Use care with your meter probe so that you do not short out 2 of the pins while taking a reading....
That could cause Power supply failure... Unsure

...

Please post readings..
Thanks...

Later...Ron.M... Cool

...
Veteran & Retired TV technician

(This post was edited by Ron.M on Oct 12, 2014, 5:56 PM)

Misfire
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Oct 13, 2014, 8:02 PM

Post #10 of 48 (9721 views)
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Re: [Ron.M] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

OK, here ya go, everything plugged in and TV turned on,,,,1) -1.36V grn wire. 2) -2.32V yel. 3) 0.0 org. 4)21.0V red. 5) 1.41V brn. 6) .56V blk. and I used the cable in for grnd.

Ron.M
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Oct 13, 2014, 9:13 PM

Post #11 of 48 (9713 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Misfire;...

Proves my suspicion , power supply MAY be bad...

Now do the same exact thing , except unplug connector J19701...
Post readings...

Later..Ron.M.... Cool

..
Veteran & Retired TV technician

Misfire
User

Oct 14, 2014, 4:08 PM

Post #12 of 48 (9700 views)
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Re: [Ron.M] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

OK, TV on and rainbow connector unplugged,,,Every pin 1) thru 6) is dead, I do have 120 AC going in on blk and red 2 term plug,

Ron.M
Veteran

Oct 14, 2014, 5:30 PM

Post #13 of 48 (9691 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Misfire;..

OK , 100% Power supply bad !!!..
Sorry about the bad news...

One more thing to do before it's condemned...

USE CARE when reading these voltages !!!
You will be on the "hot" side of AC..
Reconnect connector J19701..
STK730-130 has 12 pins...
Only 2 have readable voltages according to my manual...
Use the "-" side of C19702 for ground...
C19702 is a large (220 mfd @ 200 vdc) lytic cap ....
Read "+" DC voltage on IC pin 4..
That voltage should be low (Under +5 vdc)...
Read voltage on IC pin 11...
That wil be much higher...(About +150 vdc OR higher)...
Please post readings..

There's only one lytic cap that I can point a finger at...
That would be C19703...(10 mfd @ 63 vdc)..
Comes off pin 1 thru R19715 thru R19716...
You can try changing that cap with a 63 or 100 vdc new cap..
OBSERVE CORRECT polarity...
After that , the best thing to do would be to replace the board with a WORKING used or repaired board...

BTW:...
Where did you get the replacement STK730-130 IC from ???
How much did you pay for it (Excluding s&h) ????

Later...Ron.M... Cool

...
Veteran & Retired TV technician

Misfire
User

Oct 14, 2014, 6:07 PM

Post #14 of 48 (9683 views)
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Re: [Ron.M] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Hey Ron, I have 0.0V on term 4) and 170VDC on term 11)
There is not very much to that board or (power supply) from what I can see, none of the caps in the TV (from what I can see from a visual inspection) have puffy or expanding tops,,,, Not that means anything. that will be an easy fix.
Ron,,,I have been blessed to have a store almost in my backyard that's called (Audio Lab) In Georgia and they have had everything I have asked for from mosfets for moms treadmill to repair the speedcontroller to diodes in a alternator. The part I got looked exactly like the original, and was 12 bucks and change walk out.

Ron.M
Veteran

Oct 14, 2014, 6:40 PM

Post #15 of 48 (9678 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Misfire;.....

OK on the STK....

Was concerned that you might have bought a Chinese knockoff...

Try replacing the cap...(10 mfd @ 63/100 vdc...

IF that doesn't do it , then I'd recommend replacing the board..

If you want , post the part number on the board & I'll see what I can find..

Later..Ron.M... Cool

..
Veteran & Retired TV technician

Misfire
User

Oct 14, 2014, 8:42 PM

Post #16 of 48 (9671 views)
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Re: [Ron.M] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

just got a new cap, the place I deal with even had tips and sleeve for my newly acquired Weller EC2002A solder iron,,,,but just like everything I acquire,,,, dosnt work, lol now anything bout them?? lol

jts1957
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Oct 14, 2014, 10:21 PM

Post #17 of 48 (9665 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Quote

replaced the STK730-130 on the hanging board, That brought the convergence menu back for about minute then disappeared again

I think he fried the same IC again. check for short between pins 8/9 & 11/12.
If so, I'd suggest unplugging J19701 and checking for leakage/shorts on pins 1, 2, 5 & 6 at both the socket and the jack.

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

(This post was edited by jts1957 on Oct 17, 2014, 12:33 AM)

Misfire
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Oct 15, 2014, 2:58 AM

Post #18 of 48 (9659 views)
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Re: [jts1957] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

I have the small cap and have not had a chance to replace it just yet, and the STK730-130 is shorted to the 8) and 9) terms and 11) to 12) terms also. a cap dying would cause this? will get new cap installed and see what happens, glad I was never a TV repair man, especially being paid commission, lol.

jts1957
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Oct 15, 2014, 3:26 AM

Post #19 of 48 (9657 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Pins 8 & 9 ARE supposed to be together.
Pins 11 & 12 ARE supposed to be together.

Pins 8 & 11 (or 12) are NOT supposed to be together.
Pins 9 & 11 (or 12) are NOT supposed to be together.

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

Misfire
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Oct 15, 2014, 1:11 PM

Post #20 of 48 (9643 views)
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Re: [jts1957] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

OK, the pins are as you say and even like that on the STK I removed, Have installed the small cap to no avail other than different voltages at rainbow plug while unplugged and TV on, 1).28V 2).30 3).18V to .20V fluctuation 4)-19V 5)-.40V 6)-.37V. <br> I noticed on the back side of board or solder side, seems there are a lot of little (+) signs at few places but they all read (-) on the meter. Question,,,,where the red and blk 170V AC plug in they go thru diodes by a very large cap 200/220. I cannot tell which number belongs to it but its the largest cap on board, Should the rest of the board be DC after that?

(This post was edited by Misfire on Oct 15, 2014, 1:22 PM)

Ron.M
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Oct 15, 2014, 7:36 PM

Post #21 of 48 (9628 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Misfire;...

Lets not add any confusion to the issue...
What jts1957 means is;...
Read ohms from either pin 8 OR 9 TO pin 11 OR 12 to see IF you blew the IC..
IF it reads low ohms , the IC is bad...
Simple ????
Please post reading...

BEFORE you read ohms , unplug the TV , short out "very large cap" "+" to "-"..(C19702)..
You most likely will see a spark & hear a snap ...
Thats normal..
USE CARE !!!
IF you don't & there is any large residual voltage there , you CAN BLOW your meter !!!..

The "+" signs on the bottom of the board mark the positive connections for lytic caps...
If you are reading "-" volts at ALL these places , you may have your "-" probe at the wrong ground point..

The "very large cap" is;=>...

Quote

C19702 is a large (220 mfd @ 200 vdc) lytic cap ....

You have 2 sides to that power supply..
One side is the "HOT" side which is directly connected to AC in...
The other is the "Cold" side which is the source for the operating voltages of the convergence board etc...
They are separated/isolated for safety reasons & to change AC to required needed DC voltages...

Quote

Should the rest of the board be DC after that?

Transformer "T19701" effectively does that...
The primary is the "HOT" side & the secondary is the "Cold" side...
EACH side has its OWN individual ground..
The secondary side of "T19701" is where you get the DC volts for the convergence circuits to work...

Later..Ron.M.. Cool

...
Veteran & Retired TV technician

(This post was edited by Ron.M on Oct 15, 2014, 7:45 PM)

Misfire
User

Oct 15, 2014, 9:15 PM

Post #22 of 48 (9616 views)
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Re: [Ron.M] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

OK, ohming out term 8) to term 10)11)12),,, 3 terminals on the other side of cut in board one at a time and checking both ways,,,, I get nothing. same with term 9) to the three across the split part in board, nothing, no continuity. and the way you talk about this board and being safe,,,, I am safe as I can be, I know the potential of a cap from points ignition in cars and taking this board on and off,,, I should have been bitten by now? I do know when I plug the TV in the wall there is a considerable snap and spark at the plug in, not always but mostly.

I guess this is one of those times where the repair manual say's (test with known good one) lol

(This post was edited by Misfire on Oct 15, 2014, 9:30 PM)

jts1957
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Oct 15, 2014, 9:37 PM

Post #23 of 48 (9613 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Quote

"There ain't NO 10's"

Quote

I'd suggest unplugging P19701 and checking for leakage/shorts on pins 1, 2, 5 & 6 at both the socket and the jack.

I'd still suggest ohming between ground and each of the the eight points indicated.

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

(This post was edited by jts1957 on Oct 15, 2014, 9:40 PM)

Misfire
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Oct 15, 2014, 10:42 PM

Post #24 of 48 (9608 views)
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Re: [jts1957] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Dude,,, You just got me laffing my ass off, really needed that today and being serious, hahaha, please tell me how to upload photos here,,,cause a pic's worth uh,,, a lot. lol

jts1957
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Oct 15, 2014, 10:50 PM

Post #25 of 48 (9605 views)
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Re: [Misfire] another PTK195 RCA 61" convergence problem [In reply to]	Can't Post

Courtesy of "Flash." (aka Ron.M) http://www.tv-forums.com/...i?post=157911#157911

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

(This post was edited by jts1957 on Oct 15, 2014, 10:51 PM)

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