No commercial links

Sorry, I had to close comments due to permanent spam. Too much cleanup work.

2016-02-28

Sony KDL-26EX555 - stuck in ageing mode - white screen shows TMP, TIM - TV is bricked

A friend brought me this Sony, which he got from eBay classifieds. In the ad, the owner said it had no sound. Well, that's not at all what I found.

The set would start up, flash the normal image and then show a white screen with two numbers: a temperature TMP and a countdown TIM. This is the so-called ageing mode, which can only be activated via the service mode.

In ageing mode, the power LED blinks continuously and the TV will not go to normal stand-by anymore. The remote control has no effect on anything, neither do the switches on the side of the case.

This is a screenshot from a video I took. The normal image flashed very quickly, no chance to take a normal shot.


After that, it looked like this:



I browsed the net and it seems that this happened to quite a few people with other Sony TV models. Either they inadvertently pressed some keys on the remote or the TV suddenly was in that state when it booted. One suggestion was to press the Analog/Digital button on the remote. Didn't work.

This looks like a software bug. The device is bricked. It is impossible to get out of the aging mode without the means they have at the factory.

There are two choices:
  • Look for a local Sony service, who may have the means to unbrick the TV
  • Buy a used main board (# 1-884-958-21). I only found some for the EX553, which has no sat receiver. 20 british pounds. Not so bad, may be cheaper than the Sony service.
I'll let my friend decide.

In the meantime, Sony support suggested pressing the Up key on the remote together with the On/Off button on the TV. Nonsense. Another suggestion was to press the Menu key on the TV for longer while plugging in. Also nonsense. They don't have a clue!

Sony Service Manuals used to be better


The service manual of this TV has some nice color images for assembling and disassembling, and some block diagrams, which explain things on a high level. But no schematics for anything. What happened to Sony? I am disappointed.

2016-02-04

Panasonic Plasma TX-P50STW50 - 7 blink error code - Z-sustain board TNPA5524 defekt

It was about time to fix a Panasonic Plasma TV, my favorites! I recommended this one to a friend, who was looking for a 50 inch. It was listed on eBay. The seller had observed the 7 blink code. My friend got it for 200€.

A look inside:


Panasonic finally picked up the idea to install a woofer speaker with its own cabinet. The TV also sports WiFi and Bluetooth for the 3D glasses. My GT30 has none of that. 

The first check in a 7 blink Pana goes to the SC board (Y-sustain). It had no short on the supply line and none of the semiconductors measured suspicious. According to the service manual, on this model, the 7 blink can also be caused  by the SS board (Z-sustain). And lo and behold, this one had a short on the supply line.

A closer look revealed shorts on the following semiconductors:

As the IGBT transistors are working in parallel, I unsoldered them and measured them individually. As it turned out, only three of the 30F132 IGBT transistors were dead. Both from the center and the one in the middle of the group of three.

Anyways, a new board was necessary. The plasma TVs of the previous generation used the 30F131, which has a lower current pulse capability. I could not cannibalize my spare SS board.

My favorite supplier flattvparts.co.uk had one board left. Now, you need to be very careful here, because there are many versions of the TNPA5524 board around, which all look similar, but they aren't equal. 

Check this label:

There are RFUU, REUU, RHUU (and probably more) types around. Each has a different configuration of transistors and coolers.

The new board fixed the TV. I found brownish areas on the old board, a sign of high temperatures. To improve cooling, I unsoldered all coolers from the old board and put them in the areas where the most heat seemed to build up. I also measured the temperatures. I put a bigger cooler on the transistors, where one maybe had been the reason for the failure.


On the SC board, I put the same cooler on four transistors, which seemed to heat up more than average.



Evangeline Lilly was beaming into the room. An image only the best plasma TVs are capable of. Just compare it to the Philips LCD I fixed recently: Lilly on LCD. The difference in color spectrum is striking.


This is a brilliant TV. The picture is awesome and finally, also the sound has become acceptable. The ST series misses more fine-grained image adjustments, but the available modes work very well right out of the box.

Here is the list of the high power semiconductors:

SC only
D RFUH25 (SC)
D DAF30A (SC)
T DG301 (SC)
T 30F131 (SC) can be substituted with F132
T R5007 (SC)
T RJP6304 (SC)

SS only
T DG302 (SS)
T RCJ200 (SS)
T RCJ220 (SS)

SC & SS
D RFUH20 (SC, SS)
T 30F132 (SC, SS)
T 45F132 (SC, SS)