Hi All,
I have one of these TV's that just went dead on me. I don't have the PS values handy, but from what I recall, the PS-On and the DIM-On were both showing as 0V when the unit is on and off.
It does the typical power on, no backlight, sound, video, and won't turn off until you pull the power.
What's interesting is there's some definite "switching" voice coming from the main PCB. I'm not sure if that's due to the EEPROM being bad, and the CPU not firing up, or if something else is going on. That switching noise appears on both the "dead" PS-On and DIM-On lines measured with an oscilloscope.
I'm happy to buy a new EEPROM, but my big question is, what causes the corruption/failure? A batch of bad chips, crappy design of the display, failing regulators? I'm just worried that I'm going to have to keep replacing this IC every few years. =/
Attached is a picture of the main board. The EEPROM IC is a winbond chip. I thought I had a picture of just it, but I'm not able to make out the exact IC model. Also interesting is there's, what looks like, a silver sharpie mark on U408. Not sure if that's from someone confirming it worked, or what. If anyone has values for what various regulators should output, I can also check and confirm that. Seems like there are a lot of redundant VRs... several 3.3v regulators, several 5V regulators. Guess that's just cheaper than paying for an extra layer on the board. The build quality of these TVs is pretty darn crappy. =/
I have one of these TV's that just went dead on me. I don't have the PS values handy, but from what I recall, the PS-On and the DIM-On were both showing as 0V when the unit is on and off.
It does the typical power on, no backlight, sound, video, and won't turn off until you pull the power.
What's interesting is there's some definite "switching" voice coming from the main PCB. I'm not sure if that's due to the EEPROM being bad, and the CPU not firing up, or if something else is going on. That switching noise appears on both the "dead" PS-On and DIM-On lines measured with an oscilloscope.
I'm happy to buy a new EEPROM, but my big question is, what causes the corruption/failure? A batch of bad chips, crappy design of the display, failing regulators? I'm just worried that I'm going to have to keep replacing this IC every few years. =/
Attached is a picture of the main board. The EEPROM IC is a winbond chip. I thought I had a picture of just it, but I'm not able to make out the exact IC model. Also interesting is there's, what looks like, a silver sharpie mark on U408. Not sure if that's from someone confirming it worked, or what. If anyone has values for what various regulators should output, I can also check and confirm that. Seems like there are a lot of redundant VRs... several 3.3v regulators, several 5V regulators. Guess that's just cheaper than paying for an extra layer on the board. The build quality of these TVs is pretty darn crappy. =/
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