CRT based RPTV Convergence Repairs

**lcaillo** · **03-20-08, 07:05 PM**

Read the posts at the start of the thread.

**ibokie** · **03-20-08, 09:27 PM**

I've read the thread but I really don't know how to read the schematic to determine which resistors go with the STK's or at least how many there are . One of your post says the kit has more resistors than I'll need so that kinda of eliminates me just changing out what comes with the kit....

**lcaillo** · **03-20-08, 09:42 PM**

On your set the resistors are the large ones standing up off the board between the ICs and the red, green, and blue convergence connectors, to the left of the ICs looking from the back. If you go the right kit for your set, just change them all.

**ibokie** · **03-20-08, 10:08 PM**

Thanks guy.Your posts have been very informative. They are basically what convinced me to try this myself. I don't mind a tech earning a living but when I get charged 400 bucks to do a job that only requires less than 40 bucks or so for parts and doesn't last longer than 14 months, not to mention that I had to deliver and pickup the TV , that kinda rubs me wrong the wrong way.This ain't brain surgery.It's fixin a TV for cryin out loud !

**lcaillo** · **03-20-08, 10:38 PM**

This happens to be a very routine repair. Most repairs are not so simple and service shops lose money on those, so they make it up on routine repairs. $400 is still more than I charge, even with a service call to the home to repair the set. This is not a repair that should require the set to go to the shop. It is also not a repair that should have to be repeated in 14 months. It is likely that the tech either used inferior parts or missed something. If it is the latter, it is likely that you will miss it as well.

**ibokie** · **03-20-08, 11:31 PM**

Miss it I might , but I'll feel a lot better about it knowing that I tried . I'm out $37 for the parts ,$9.95 shipping and $15 for the schematic. Not to mention the satisfaction of knowing that I tackled something new. Thanks for sharing your information on the web like this. Knowledge is wealth and a dumb ol' Okie like me needs all the help I can get ! The parts should be here in 3-6 days , I'll let you know how it turns out.

**m109ner** · **03-21-08, 10:54 AM**

Icaillo,

First off thank you so much for all the detailed information on repairing convergence problems with replacing IC's and resistors. I have a Hitachi 57F500A, rear projection TV with the infamous convergence problem. Bought the SANYO IC # STK-394-160’s kit with the resistors. I removed the old STK392-150 and replaced with the new 160’s. Checked and metered the resistors on the board and all seemed fine. Installed everything back together and I get no video and no sound.

The original problem was a convergence issue but I had video and audio. After replacing the IC’s, the TV turns on but no audio and no video. What did I do wrong? Do I need to replace all the resistors? The soldering on all of them looked fine. I recently did this same repair on a 55” Toshiba and it worked like a charm.

Please help.

**lcaillo** · **03-21-08, 01:15 PM**

You likely pulled a connector loose. Check the boards carefully.

**m109ner** · **03-21-08, 01:32 PM**

Please excuse my ignorance...connector?

Thanks for the quick response.

**lcaillo** · **03-21-08, 02:05 PM**

Connectors - those things on the end of a wire or bundle of wires that plug in to the sockets on the circuit board.

**m109ner** · **03-21-08, 03:00 PM**

I took pictures of all the connector locations prior to pullingn them. Double checked all those connectors (three from the firing guns RBG, board jumper connectors, etc) and they are all in. Also tried pulling large red, blk, white wires from large round black "box" next to IC Chip and heat sink but could never remove them completely. Do these control audio/video? Is there an easy way to pull these? My next step is to pull the board out again and confirm that there are no cold solders on the IC chip pins. I doubt it, but it's worth a try. The weird thing is that I get no Video and no Audio.

Really stomping me! Any other thoughts, I'd really appreciate it.

Thanks

**lcaillo** · **03-21-08, 04:02 PM**

Obviously something changed between the time it worked and it didn't. The most likely culprit is something that you did. It is certainly possible that some other fault coincidentally occurred, but this is pretty unlikely. You need to figure out what you did. This is part of the skill of repairs that I cannot communicate online. I cannot find it for you.

**ibokie** · **03-22-08, 06:43 PM**

Icaillo,
As far as the convergence problem goes with the STK's and resistors, heat seems to be the culprit. I read in one of you earlier threads that you don't recommend connecting a fan to the TV's board. I agree that it could be a cause of some type of audio or visual frequency interference with the set or a power issue. Have you ever done a fan and/or do you have any suggestions on hooking up a cooling fan that would turn on and off with turning on or off the TV. Sure seems it would be a benefit to the components.

**lcaillo** · **03-22-08, 07:21 PM**

I do not do fans in any sets. My issue is less with interference than with drawing too much current and with the possibility of problems with the connections and wiring. There are external fans that you can find that run based on the temp. I have never had recalls on convergence repairs. Cooling cannot hurt, but there is no reason to wire a fan to the internal circuits of the set.

**cordless89** · **03-23-08, 07:31 PM**

For lcaillo:

I have replaced some stk392-110 with the formentioned stk394-160 series. I am still having an issue with the convergence drifting a little bit here and there, both red and blue. It is usually a small drift easily corrected in the service menu but thats getting old. Do you know what could be causing this? BTW - The set is a Panasonic PT-53WX42F.

**lcaillo** · **03-23-08, 07:43 PM**

Drifting how in terms of what part of the screen, which color, which direction, over what period of time? Is it stable after a period of warm up?

**cordless89** · **03-23-08, 07:50 PM**

There is no real definate area but it does seem to be the red more often than blue. Once adjusted, its fine for a few days, maybe a week. My wife thinks I being way to picky and wanting an excuse to get a new one but...

**lcaillo** · **03-23-08, 08:37 PM**

When are you evaluating it? After how much warm-up? Which direction does it drift? Horizontally, vertically? Always the same, how much? Without more information it is hard to be of help.

**Panda** · **03-26-08, 06:38 PM**

Hi, I have a very simple and quite possibly the most dumbest question but I wasn't sure.

The STK394-160E resistors, if I ordered them from TRITRONICS or Vance BALDWIN ELECTRONICS does the Hitachi Kit come with 2? or just 1? Cause I see the price going for $37.65.

I have the same problem as everyone else. (See Pictures Below) My model is Hitachi 53SWX01W and the original resistors are STK392-110.

Thanks in advance.

**lcaillo** · **03-26-08, 07:44 PM**

The kit comes with two STKs, which are the ICs, not resistors. It also comes with a number of resistors. Make sure that you get the right kit for your model television or the resistors may not be the right values.

**Panda** · **03-26-08, 08:17 PM**

Quote:

lcaillo wrote:

The kit comes with two STKs, which are the ICs, not resistors. It also comes with a number of resistors. Make sure that you get the right kit for your model television or the resistors may not be the right values.

Ah, thanks for the clarification. And that's what I mean. lol, I'm just not familiar with the terminology. I'm glad I asked the question or else I'll be paying twice as much for 4 when I only need 2.

**Joe Gifford** · **03-29-08, 03:38 PM**

Hi I have a Hitachi 43FDX01B My picture went out and it was after some convergence issues started. It had been fixed once before by a tv guy for the ususal price. He replaced the 110's with 110's. Well after reading this post I bought the upgrade 160 package that hitachi puts out. It came with some resistors and a nice explanation page (with a good picture) of where the replacements go. bought it here. https://www.ued.net/ued/addItems.do?itemCode=HIPX480301

I put these in and the resistors. I'm not a tv repair man,,, but I think I did ok.
My picture came back on.
The BlUE is way off and I can't move it.
The picture is bowed down on the top and up on the bottom.
I can't get the convergence to align.
I tried going in the grid. I have the service manual. And my remote.
It's too vague on how to adjust.
Is this an adjustment? I can align? I'd really appreciate any help don't hesitate to e-mail me if you can help. thanks Joe

**lcaillo** · **03-30-08, 11:38 AM**

Check your work. If the pix is bowed and you cannot adjust the blue, you likely have a bad connection, missed a resistor, or bridged a solder connection. Sometimes you can have a bad convergence generator module, but this would require some troubleshooting with a scope to isolate.

**Scuba Steve** · **04-01-08, 01:31 PM**

Wow, this is really a great and informative thread. The best on the internet, and that is quite a claim!
I have a Toshiba 55h70 that I am in the process of changing out the STK's and I am a little confused about the resistors. I have identified the resistors related to the IC's, R7711, R7721,
R7116, R7726, R7736, and R7731. The service manual descibes them as "MF, 1.2 ohm, 2W", but I have been told from Techs on other sites that I need 1.8 ohm 1W resistors. The 1.2 ohm 2W resistors are a bugger to find on the internet.
I have already ordered the 1.8 ohm 1watt resistors, will they not work?

**lcaillo** · **04-01-08, 03:25 PM**

The service manual shows 1.2ohm. Generally these values are pretty critical. Who told you to use 1.8 and where did the information come from? If it was not from Toshiba it would be very suspect. The difference between the two could cause some pretty drastic linearity changes.

You should be able to get the resistors from several of the suppliers that I have listed in the parts distributor thread like Tritronics or B&D. IIRC the Hitachi kits that have the STK394-160 that I use as an upgrade in these sets mostly come with 1.2 or 1.8 ohm. I will look to see which one does.

edit: It looks like all of the Hitachi kits come with 1.5 or 1.8 ohm resistors. You should still be able to get the 1.2 ohm from most Toshiba or Hitachi authorized distributors.

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