Philips Magnaovox TP2785 C221 No Picture
I have a Philips/Magnavox 27" CRT TV on the bench which has no picture. Chassis number is 27K800 7591, Model is TP2785 C221. This is a 2001 vintage TV set.
The anode high voltage is present and normal, the CRT filaments are lit, there's sound and apparently normal tuner activity. The screen in a darkened room shows a very faint gray raster with horizontal lines across it and there's a brief normal-brightness full screen flash of white when it's powered off.
I am an electronics technician (but not a TV tech.) I checked all the electrolytics for ESR issues and they were all fine. The 10 Ohm resistor on the CRT board which goes open and which is a common fault on this model, is good. There are no obvious burned or defective parts on the main board. I curve traced all the diodes and the discrete semiconductors and they are all good.
I don't have any schematic or documentation on this set but I am suspecting the processor IC or whatever IC controls the video has gone bad. There are two larger IC's on the board, I assume one is a CPU. My question is whether anyone else has run across this problem before and what their solution was. I hate to waste money replacing the IC's (there are only three) presuming they are even available if it may be something else. I do have vacuum desoldering stations so removing a 40 pin IC is no problem. Also, does anyone have a favorite source of these IC's? I have never dealt with Philips before and was wondering if there are alternate sources. I don't think ECG carries the proprietary chips...