Philips 37PFL8694H/12 - picture solarized - another AS15F chip defect on TCON board

Have I already said that repairing AS15F chip defects is becoming a routine? This is my third repair of this type.

I like the higher Philips models. They usually have a nice image and proper sound. This one came in with a solarized picture, which seems to be the standard failure on 2008/2009 models. Some colors were off. Not as bad as the last one I fixed, but unmistakably, this was a defect AS15 chip on the TCON board. I have those chips on stock, so this was going to be some solder work with a very good chance of success.

Apart from the image defect, this set was in mint condition. Not one scratch.

The panel and TCON has been manufactured by AU Optronics (AUO).

Wires flopping in the breeze everywhere. Oh my.

First I was happy to see the TCON board not buried under the mounting bracket for the stand, but this was even more silly. The plastic frame, which goes all around the device covered it up:

Hidden screws :-(

With some screws removed and careful bending I managed to remove the cover to gain access to the gamma voltage test points. This would give me the final confirmation of the defect.

I was right. A couple of voltages were inconsistent. They must continuously increase from left to right. This board had a number of jumps in the voltages. No total failures, just half a volt off. This was consistent with the screen symptoms.

Ok, chip removed, solder pads cleaned. I prefer to use solder paste for the bottom pad. It makes the chip stick nicely to the board, and soldering the pins is easier. I first soldered the pins with the iron and then reflowed the whole chip with hot air.

This heat conducting block cannot be reused.

I had no 6mm material at hand, so I stacked a 1.5mm on a 5mm. I carefully had to position it under the cover because it would stick immediately and move out of its place.

TCON back in the TV. All good. Frau Johansson looked content, albeit a little tense, and I am happy about the successful repair.

This TV is a good one. I generally prefer the image of a CCFL panel over the LED types. The panel has no backlight bleeding and is perfectly even lit. The colors are natural and precise. There is a white balance adjustment available, albeit no expert mode. Sound is more powerful than average.