CRT based RPTV Convergence Repairs

**ainc** · **11-23-07, 01:17 AM**

lcaillo, you rock!
Thanks for your time and sharing your knowledge. As a newbie I learned 2 tings. First, I'm probably going to pay someone with experience to do the repair (don't want to burn down the house). Second, the tech I had originally called for a quote is a bum! He quoted $600 and wasn't a fraction the professional you are. Thanks for your help!

**lcaillo** · **11-23-07, 08:24 AM**

You are welcome, but please post some details about the repair when you get it done. I would be curious what it ends up costing and where you are located. While $600 for a convergence repair is twice or more what I charge, some parts of NY have a cost of doing business that is proportionally that high. If you do get it done significantly cheaper by a legitimate business, I would be very curious to know the names of the shops so that we can quiz them on how they price repairs. Consumers need to understand how servicers come to charge what they do. Some are a rip-off, but many just are trying to make a living.

**j.m.s.** · **11-24-07, 06:29 AM**

Hello, My Pioneer sd-533hd5 broke agin. I had the convergence chips repaired last year for $600. Now when I try to turn on TV it turns right off. I checked all fuses and they are fine. There is a red led light on , on one of the boards. Is there a way I can fix this myself, is it related to convergence repair? To pay another $600 for a 6 yr old tv seems rediculous. At that point I could have bought another brand new one. Any help would be very appreciated,

Thanks, Joe

**lcaillo** · **11-24-07, 09:38 AM**

I don't do a lot of Pioneer anymore, but over the years I have learned that most pioneer sets need to have hundreds of solder connections re-done, as they never seemed to master the process of getting parts soldered in a manner that would last very many years. There are lots of possibilities and one would need some troubleshooting experience and service literature to do any real evaluation of the set, but I rarely service a Pioneer that does not start with resoldering lots of connections.

**bdrew** · **11-27-07, 09:25 PM**

Hi, great info!! I should be able to put it to good use. But first, I must be sure the problem I see is due to a convergence failure. It seems the only issue is with the blue. There are arcing blue lines through the bottom 1/3 of the picture and the upper corners are blue. I attached a couple pictures to illistrate. Please take a look and advise.
Thanks!

**lcaillo** · **11-28-07, 05:48 AM**

Looks like a convergence issue to me.

**drdoan** · **11-28-07, 11:00 AM**

Either a pincushion amp or the convergence board is defective. Probably will require a service call. Dennis

**lcaillo** · **11-28-07, 11:41 AM**

All pincushion correction in these sets is done via the convergence generator and convergence output amps. One channel (blue vertical) of one of the ICs is likely bad, with perhaps a resistor or two. Read the posts ar the top of the thread for more info.

**bdrew** · **11-28-07, 03:29 PM**

Thanks for your reply! Another question, if I order the Hitachi kit, will the resistor values be the same as what is in the board?....this is a Panasonic model PT51HX41E, chassis #AP820.....which kit should I order?
Thanks

**lcaillo** · **11-28-07, 06:24 PM**

No, they will not be the same. Each set has a unique circuit even if the chips are the same. If you just want the chips get the one that you can find cheapest.

**martaroony** · **11-28-07, 09:15 PM**

Quote:

lcaillo wrote:

While the 12 volt supply might be able to handle the extra load, for safety reasons I would recommend not trying it. You also may get some noise feeding back into the video or audio circuits from the fan. Just keep using the wall wart.

Just wanted to say thanks lcaillo, for all your time to put this thread together , I was very nearly caught up in the extorsion that my local repair guy (Gold Coast, Australia) was about to inflict on me.

He would not even look at the set unless I let him pick it up, and that was $110 ,whilst the repair would start at $300 on top of that. He had no phone credit to return my calls , and I dont think I would have put my dog in his van , let alone my 134cm.

So feeling helpless, and after sneakily finding out what and where the convergence board was, I came up with the STK392-120 chip number , entered it in the google search , and well here we are.

Cut a long story short, In australia I cant buy these IC's any cheaper than $130 each+ freight, so after buying them online from "Electronic Repair Kits" in Canada (Got 2 Pairs ,1 Pair For later) They arrived in 4 days and cost $5 air freight, which was cheaper than the freight in my own country. Also the IC's cost me $15 each as opposed to $130 each over here.

So after following clear instuctions, that I found on the net.

http://home.earthlink.net/~oleg.fili...ergenceFix.htm

And then proudly turning the TV on, in front of the "astonished" Wife and Kids , Im glad to say if I wasent a legend in their eyes before ,I certainly am Now ! (thanks to you)

So one question before I wind it up?

I have noticed the 2 big heat sinks on my IC board, Getting very hot.

( by the way my TV is an LG PT53A83T ), ,

So much so that I can only hold my hand on them for a matter of seconds before getting to hot to touch.
This cant be good , and after reading the thread and any other thread I can find on this , Was wondering is this normal ?

I noticed one Gentleman in this thread putting a PC chip fan , on his heatsinks which seems like a great idea , however wouldn't he have to keep turning the tranformer on and off with the TV, Or can you get them that only turn on with the sencing of heat ??????

Any advise is appreciated, and once again thankyou for your great thread.

Kind Regards Marty.

**lcaillo** · **11-28-07, 09:29 PM**

These ICs run hot, but some sets hotter than others. Excessive dc ofset or excessive correction at the edges of the range of the chips can make them run hotter. I don't have a problem with fans, as long as they are mounted externally and do not use any of the internal power supplies in the set. I would start by verifying the setup is consistent with that in the service literature for your set and that there is no more than a couple hundred millivolts of dc on the inputs to each channel of the output ICs.

**martaroony** · **11-28-07, 09:46 PM**

Quote:

lcaillo wrote:

These ICs run hot, but some sets hotter than others. Excessive dc ofset or excessive correction at the edges of the range of the chips can make them run hotter. I don't have a problem with fans, as long as they are mounted externally and do not use any of the internal power supplies in the set. I would start by verifying the setup is consistent with that in the service literature for your set and that there is no more than a couple hundred millivolts of dc on the inputs to each channel of the output ICs.

HHmmmmm, thanks lcaillo, soldering in the New IC's may have elevated me to Legend status with the family, but Im out of my depth well and truely now.
Any Ideas on how I would start to verifying what you speak of.

Regards Marty

**bdrew** · **11-29-07, 12:34 PM**

Icaillo,
Thanks, I'll order individual STKs. Where is a good source to order a schematic? I'd like to know what resistor locations to check and have an idea what resistance to expect. Is it a good idea to relace the caps as well?
Thanks again!

Brad

**lcaillo** · **11-29-07, 04:02 PM**

Quote:

martaroony wrote:

HHmmmmm, thanks lcaillo, soldering in the New IC's may have elevated me to Legend status with the family, but Im out of my depth well and truely now.
Any Ideas on how I would start to verifying what you speak of.

Regards Marty

I am happy to provide general advice or obvious symptom repair info, but cannot provide step by step troubleshooting on specific sets, nor start a tutorial on service torubleshooting. If the info that I have provided is not sufficient, I strongly suggest that you get a professional involved.

**lcaillo** · **11-29-07, 04:08 PM**

Quote:

bdrew wrote:

Icaillo,
Thanks, I'll order individual STKs. Where is a good source to order a schematic? I'd like to know what resistor locations to check and have an idea what resistance to expect. Is it a good idea to relace the caps as well?
Thanks again!

Brad

The resistors that usually get damaged are the ones on the output of the ICs. It is not common to need to replace capacitors in most convergence repairs. The sure way to get a service manual is to go through the manufacturer or its authorized parts distributors. You might also find places to download it online. I will caution you that navigation the electronic versions of the Panasonic manuals is the most astoundingly obtuse of any electronic documents I have ever seen. The paper versions are more easy to figure out for most people. You also may not get everything in versions provided online outside of Panasonic's distribution.

**bdrew** · **11-29-07, 05:00 PM**

Quote:

lcaillo wrote:

The resistors that usually get damaged are the ones on the output of the ICs. It is not common to need to replace capacitors in most convergence repairs. The sure way to get a service manual is to go through the manufacturer or its authorized parts distributors. You might also find places to download it online. I will caution you that navigation the electronic versions of the Panasonic manuals is the most astoundingly obtuse of any electronic documents I have ever seen. The paper versions are more easy to figure out for most people. You also may not get everything in versions provided online outside of Panasonic's distribution.

Thanks again sir! I was able to find the STK394-250A (to replace STK392-110) at ACME for $13.49 each!! They are around $25 elsewhere. They claim they are original Sanyo parts...but the price is quite low. I guess I'm the suspicious type

I value your opinion

It sounds like I can do without the schematics...maybe just follow the traces from the output pins. But I may need the service manual for alignments??
It appears I nearly have all the info I need....then I can quit bugging you. It's been very enlightening!

Brad

**lcaillo** · **11-29-07, 07:01 PM**

Acme is one of the few suppliers that goes to great lengths to assure that they provide only first quality original parts. They also have some of the best prices. I would verify with them that the stk394-250 is a good sub for the stk392-110. I think that it may have a different muting circuit and may not work in some sets. I use the STK394-160 to replace the STK392-110 and have never had a problem. I have only used the -250 in sets that were designed around it. Glen at Acme should be able to give you the scoop. Just email him. I don't buy the -160 from him because I get them in the Hitachi kits for the lowest price, and he is not a Hitachi distributor. For products that they do have, you can count on them to be a great supplier.

You definitely need the documentation to align the Panasonic. The service menu and convergence adjustments are as poorly designed as their electronic service manuals.

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