TV trouble shooting help!

Hi JMSK

It sound like the same problem as mine. After opening up I decided to replace a part (Sort of like a transistor on steroids).

It lasted for about a day. I then replace it and included a big oversized heat sink. This time it only lasted 30min.

I went to the shop and bought 3, the first lasted 3 min. the second 3 seconds and it went crack , pop bang. The 3rd I crushed with a hammer to save me the trouble of soldering.

I believe the real problem is the high voltage drive coil (Lopty or something) and amateurs like me should stay away from them.

I store the thing away until I am retired and may decide to resign from life.

Hey! just a thought but can't you do what I've done a few times and ring technical / repair department saying you run a repair business and you have a model NNXXXNNN of theirs to repair.

If you get the right guy he will send you a manual or he will tell you what buttons to press to read the error code display...

Then you can hopefully ask to buy a replacement card etc...

Its worked for me several times...

Another trick is to google - I'm serious!! - My photocopier packed up 10 years ago repair was too expensive so I googled the error code and found complete instructions on the web for dealing with it!!

John.

Excellent Guest!!!

You really must sign in... LOL

Yeh:

you are right, Trying to pull a funny why was it so hard? I've worked with modern equipment for repairing PCB's. The average guy just does not have the tech to do surface mount repairs.

So if you cannot get it to a repair site, re-cycling, donation, discarding, or prayer seemed viable alternatives. Did not want do go to up set stuffed shirt types.

Hi dbdwoods

Claiming my guest post for yourselves is not good. (only joking)

I am voting a GA here for your guest post.

I am a self confessed DEY (Do Everything Yourselves) fan and like struggling with electronics.

My latest project is to repair an old 386 laptop with a broken diode (my assessment) but my problem is I cant even get the box open. What is my options? Should I get a gynaecologist to replace the diode through the modem plug?

I just always get mis-interpreted, was only thinking that the voodoo response was to my first off-topic remark, then built up to the next level.

A lot of my off color stuff gets people riled up. I dunknow why some folks are thin skinned, so I have a built in wondering on what makes people tick?

I would still return it under warranty or write them a letter. The manufacture will mostly still cover it under the warranty. No manufacture wants to hear that there product failed the day or even just a month after their warranty ran out. Does not do well on the marketability of their products.

Would you have bought this product if a friend of yours had bought one and told you it failed a short time after the warranty ran out. I think not but if they told you that even though the warranty ran out the manufacture corrected the problem. You would be more inclined to by their products.

Even thinking about trying to repair a TV without a full circuit diagram, a 'scope and a mug of tea is bonkers.

Del

I started repairing TV's in the early '50.s when you took the tube caddy to the house and checked the tubes...put in a couple for under $2.00 each...charged $5.00 for the house call and went on your way to the next call.

I quit repairing TVs about 10 years ago when my eyes got so bad I could not get the transisters in place to solder them in and I would not attempt to repair the above one without a Scope and diagram if I could see good again.

Good luck and Post what you intend to do.

John SE Texas

goto electronicrepairguide.com and buy his ebook how to test electronic component. or goto jestineyong.com you can LCD TV REPAIR or plasma tv repair ebook by kent liew you buy it. you can use it for your tv.God bless you.

I have corresponded with Kent Liew. He seems to be very nice and very knowledgable about a diverse amount of electronics in the Television repair business. However, as far as the plasmas go, he does not repair to component level on Plasma boards. He only changes out the boards and says it is normally not economical to repair these boards like the X-Sus, Y-Sus, Y-Buffer, and Logic board because parts are not available (as I am finding out). I haven't bought his book but he has emailed me that the information he provides shows the symptoms and then tells what board(s)to swap out which unfortunately doesn't help me.

I need board level repair tips. I have been blindly trying to repair an X-Sus with 2 shorted Q's(I am assuming FET devices). I know they are transistors anyway but can not find the numbers for these Q's on line or through cross referencing to NTE manual or other sites. The number on the Q's are RJH30E2. The problem is that the signal is overdriving the transistors causing them to go into thermal run-away and short out. When one shorts, so does the other. I have three of these identical part#'s on the Y-Sus that also short (all together). If the Y-Sus is bad it blows out the X-Sus, however the X-Sus can be expendable if you know how to fix them each time. But back to the Y-Sus now. There is also a Turbo Diode along with the three Q's that are all shorted. I don't have the number for it right now but it was also shorted and I replaced the Diode and Q's, and was reading all my resistances correctly from a good board reference. When I put the repaired board into the set to test, it came on and after 3 seconds it blew out the X board. I was so frustrated! At that point I threw a meter across the Q's and they weren't fried, however the diode was fried again. Without writing a book, there are no schematics (or I can't find any) for just a basic X board or Y board. I could sure use some help. Any suggestions? These Q's and Diode I am referring to are mounted on the heatsink of both X and Y Sustain boards. Any advice would be greatly appreciated!.

Olive

Man! Are these guys from he stone age or what!!! Today, when you fix a TV, you open the back, check which one of three or four circuit boards are bad, then you purchase that board and replace it.

What they're describing is like someone finds out the graphics card in your PC has gone bad - they want to find the exact bad part on the graphics card and replace it! We all know that the appropriate operation in this case is just to replace the damn graphics card!

Woof!!! Hey! Old guys!!!

Hi,i have never worked on your model of TV but i have had similar problem as yours with other makes where the vertical switching transistor would be burning a little time after replacement.What i discovered was the problem with most of them is the chopper transformer, replacing this together with transistor solved the problems.The shortdown is caused by the usually large control IC that controls all the functions of the system and so when it senses any abnormal voltage/current level,the whole system is short down and the standby light will be blinking.

Thank you all for taking the time out to comment on the thread. I managed to narrow down the problem with the help of another site; Two fuses in the main board are gone as a result of a fault in the convergence board. I am waiting for the manual & schematic to arrive and then weigh in whether to repair it muself or let the service man handle it.

Again thank you all very much.

JMSK

But was I right? "Which little board is bad, then either fix or replace the board."

Don't try to repair switching power supply unless you know how to build one.

The part that you found burnt or fried usually is NOT the one that cause the problem. It just the victum. So replacing it will cause something else to blow. You'll need to find out why it blow before you can attemp to fix it.

I had a blow cap in my computer power supply. I replaced it and end up with a blown motherboard, hard drives and other item plugged into the motherboard.

TV has very high voltage circult so any mistake will be fatal.

...Or quasi-fatal.

How did fixing the one bad cap in your power supply blow up the rest of yo' mama's board?!

Don't know. Must be something else is wrong in the PS. The cap blow again and other equipment die with it. I suspect high voltage surge before the cap die.