Friday, February 26, 2010

Polaroid TDA-03211C red light, does not power on

A few days ago receive a Polaroid TDA-03211C which was powering on to red light, but refused to continue past that.no matter what.


The power board had the main capacitor of the SMPS visually swollen and I decided to replace it, but that didn't help. It looked the power was just fine and I could measure its output.

That left the main board 200-107-GT32XA-AH REV:A as the only component to blame.

After examining the board I found nothing to suggest where the problem might be and without a schematic I would better check for replacements before starting to debug.

Well all 200-107-GT32XA-AH version on Internet had been recently sold!

eBay, ShopJimmy, Discount-Merchant - nobody had it , although reportedly all of them had it at some point, some actually rather recently.

However, I realized there was another board in circulation, the 200-107-GT321XA-BH one.

At the time of writing this it is still available for $125 on eBay from several vendors.

In my opinion, $125 for a replacement board for a 32'' TV is too expensive, but I was lucky to be able to find one vendor who was selling it at a reasonable price and I decided to bite the bullet and try it.

Long story short, it worked and the TV is now just fine.

Another happy customer.

I'd like to think the problem with the board is something minor rather than overheating and disconnection of SMD processor. If you ever find out what is going bad on that board please post it here.

Tuesday, February 16, 2010

Sony KLV-40U100M problem - dead, no picture, no sound, no power - 715T1723-J

A Sony KLV-400U100M LCD arrived in shop today with no signs of life - no LED on front panel and no response to any of the buttons whatsoever. Comletely dead.

One could hear a short buzz when plugging in outlet, though, so at least power board was showing some signs of life.

So it was either power board or main board.

Power board 715T1756-F was a bit difficult to understand without a schematic as it doesn't have any indication of what it should provide, but by looking at the back of board where the connector contacts were I was able to isolate the standby power which turned out to be 5V and available.

With a little guessing I could also figure the power on signal pin and upon signalling it with 5V through resistor I was able to bring up other voltages.

That ruled out the power board as a suspect and left the main board 715T1723-J as the prime suspect.



And indeed it was!

I'll eventually blog about what I learned as it will sure help some, but for the time being I have to go....sorry.


In the meantime, if you need your own board serviced feel free to contact me.

Saturday, February 13, 2010

HP PL5060N problem - 6870QZC004A / 6870QYC004B / 6871QZH044A

There's a problem I do not remember seeing before, so I decided to note it here.

A 50'' plasma HP PL5060N has come in for repair with typical sustain problem - burned fuse, power with no image.

Turned out it was the Z sustain and after replacing the two IPMs YPPD-J015B and YPPD-J016B with new modules and doing some quick tests I plugged the board back in, replaced the fuse and turned on the TV.

The TV showed up the HP logo for a few seconds, then turned black and restarted itself.

At first I thought the problem was in the main board or the power board, since I got good image on screen if only for a few seconds, suggesting sustains were normally functional.

But I had a spare Z sustain board and for my luck decided to see if it will make the TV behave differently.

Surprisingly, it worked out well with it, something I frankly did not expect. I am glad I tried, because I would have sworn the problem was in either main board or power board.

Anyway, after further investigation it turned out that there were two problems on that ZSus board:

The R9/R91 resistors were both burned and the D3 diode was shorted.

The picture below indicates the component locations:





The R9/R91 are connected in parallel for a resulting resistance of 5 Ohm. I didn't have SMD resistors like them handy, of course, so I just replaced them with generic 0.125W pair of 10 Ohm resistors connected in parallel.

D3 is apparently a protection diode. It was completely missing in the 6870QYC004B version of the board that I had and which was functional. Call me what you like, but I had decided to leave it missing in the 6870QZC004A version as well.

After fixing R9/R91 and removing D3 the board allowed the TV to continue beyond the HP logo.

If you want YPPD-J015C or YPPD-J016C for your own DIY project or if you want your Z-Sustain or Y-Sustain repaired check out my store.

Wednesday, February 3, 2010

HIU-811-M and HIU-811-S replacement in Toshiba 37AV500U

This post is for everyone whose Toshiba 37AV500U powers on without picture.

I apologize for not posting accurately guiding pictures, but at the time I was just fixing the TV, not planning to write about it.

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A while a go I got a Toshiba 37AV500U LCD TV broght in store for repair.

The problem was it powered on without a picture and I was quickly able to narrow it down to one of the backlight inverters. Do not remember if it was the master HIU-811-M or the slave HIU-811-S.

Turned out there was only one place where I could buy one and it was like $160 - an insane amount at a time when a practically new 37'' can be found on Craigslist for about $350.

While searching , though, I realized that a completely different inverter was listed for the same Toshiba TV model. It was the LG Philips board 6632L-0506A / 37VT-Y / PPW-EE37TV-0 .
(not sure which label means what so I'll use the shortest one here - 37VT-Y. When searching you may want to search for all of them separately and 6632L-0506A will likely yield best results.)

It is not unusual for manufacturers to switch parts within particular model, usually due to supply problems.

So I figured chances are the above said inverter may be used as a substitute.

I took the leap and ordered one for $80 as opposed to paying $160 for the original HIU-811 board.

Guess what, it worked!

The 37VT-Y board replaces BOTH HIU-811-M boards as it has TWO lamp outputs.

I mounted the board on the place of the left HIU inverter looking from the back. I did so because with a little stretch I was able to directly plug the left cable for the backlights directly into the board.

I also remember that since the board was of a different size I only fixed it using the bottom two bolts; the top of the board was up in the air and I used isolator tape to stick it to base...maybe not the best solution one could think of, but I was impatient to get it working :-)

So the problem was with the wire for the lamps powered with the HIU inverter on the right side. I had to cut and extend the original right sided cable , passing the extension under the LCD (where typically the speaker cables go) and attach it to the second output of the 37VT-Y board.

Here, hope this helps...the TV worked like a charm and not only I paid less for inverter, but I was able to sell the working HIU inverter for about $40 or $50 as well, ending up with a nicely working solution for about $30!

Hope you can do too!

Check out my store at http://stores.ebay.com/coppelltvrepair/ ...
I may have a 37VT-Y board...and even if I do not, look for it elsewhere...that's the beauty of it, isn't it? :-)


Monday, February 1, 2010

Y sustain 6870QYC004B / 6871QYH039A / 6870QYC104B for 50'' plasma burned - no image

====================
2011 UPDATE:
Related article(s):

http://blog.coppelltvrepair.com/2011/10/when-6871qyh039b-fails-should-buffers.html
http://blog.coppelltvrepair.com/2010/02/hp-pl5060n-problem-6870qzc004a.html
http://blog.coppelltvrepair.com/2010/10/vertical-or-horizontal-color-lines-in.html

Related products and services:
50'' LG YSUS BOARD REPAIR SERVICE BY COPPELL TV REPAIR 

REPAIR KIT FOR LG 6871QYH039B SUSTAIN BOARD

====================

The 6870QYC004B sustain board is made by LG and used in various 50'' plasma televisions - both LG originals and branded versions like Insignia, HP, Maxent, Sony etc.


The board has several different revisions, possibly according to licensee or technology used or revision...don't know for sure.


Those boards are 6870QYC004A , 6870QYC004B, 6870QYC004C, 6871QYH039A,
6871QYH039B, 6871QYH039C, 6870QYC104A, 6870QYC104B, 6870QYC104C, 6870QYC104D and possibly others.


To the best of my knowledge each of these boards is compatible with others and can be used as a substitute.


Yesterday we got a 50'' plasma HP PL5060N in store. Customer said they heard a loud pop while watching and the screen went dark.


TV was powering on properly with no picture.


Both the dark image and especially the popping sound is a classic for burned sustain board and naturally that's what I started with.

Z sustain board was shorted (will post separately about it some time) and I replaced it (http://stores.ebay.com/coppelltvrepair/), but surprisingly that didn't fix the problem.


It is unusual for both sustain boards to burn at the same time, but apparently that's what has happened. It wasn't a short on top of that too - it didn't burn a fuse, it didn't short and I couldn't detect it by a quick resistance comparison between key IPM (intelligent power module) pins.


Eventually I decided to take out the IPM (YPPD-J015B was originally on the board) and here is what I found:


This is the sustain board with the YPPD-J015B component taken off. It usually looks much darker underneath burned IPM modules...this was surprisely clean. Pay attention of the little dusty spot at the lower end corner though:



This is an up-close screenshot of the spot:



This is the YPPD-J015B module underneath. Most of the time it is easy to see the burn, but this IPM was covered:



I took the cover off and could finally see it sure has burned. Compare the clear rectangle (this is a diode, actually) at the upper right corner with the darker rectangle in the bottom right.
The bottom has burned, and bad.