Hi. Firstly I apologise if I break any forum unwritten rules, as I'm new here. I've used badcaps for advice in the past, but I've only just joined. I'm self taught, so I don't have anywhere near the knowledge that some of you guys have, but I can only hope to keep learning and get there one day.
Anyway, I've been working on a TV recently. It's the one listed in the title. Logik L40DIGB20. It powers on fine, with the standby light turning blue as it should. The backlight turns on for a second, then goes off. Using a flashlight, I can see an image on the screen. The power supply is fine, and the inverter board is getting its 24v. From previous threads on the inverter board (SSI_400_14A0), I've heard that these boards have issues with the AO4614 mosfets failing. On the underside of the board, there is an obvious hotspot under one of the fets, however none test as shorted. The SMD fuses show continuity, the transformers all show the same Ohm reading and do not test open circuit. The Ccfl bulbs seem to light with some only glowing half way along, before turning off...as if they're not getting enough power. The electrolytic caps are all fine, not shorted and voltages seem good on test. I've heard on here that the soldering on the '000' jumpers sometimes need touching up, so I've done all of them again, adding extra solder. The main chip SEM2107 is receiving power to VCC pin. I've tried swapping bulbs around to see if it was a bad bulb, as one bulb glowed a red colour...but in the new location, it lit up half way.
If anyone could help me out, I'd really appreciate it. I'd buy a new inverter board, but without being sure that's the true issue, the cost of repair would begin to outweigh the Tv's value.
Anyway, I've been working on a TV recently. It's the one listed in the title. Logik L40DIGB20. It powers on fine, with the standby light turning blue as it should. The backlight turns on for a second, then goes off. Using a flashlight, I can see an image on the screen. The power supply is fine, and the inverter board is getting its 24v. From previous threads on the inverter board (SSI_400_14A0), I've heard that these boards have issues with the AO4614 mosfets failing. On the underside of the board, there is an obvious hotspot under one of the fets, however none test as shorted. The SMD fuses show continuity, the transformers all show the same Ohm reading and do not test open circuit. The Ccfl bulbs seem to light with some only glowing half way along, before turning off...as if they're not getting enough power. The electrolytic caps are all fine, not shorted and voltages seem good on test. I've heard on here that the soldering on the '000' jumpers sometimes need touching up, so I've done all of them again, adding extra solder. The main chip SEM2107 is receiving power to VCC pin. I've tried swapping bulbs around to see if it was a bad bulb, as one bulb glowed a red colour...but in the new location, it lit up half way.
If anyone could help me out, I'd really appreciate it. I'd buy a new inverter board, but without being sure that's the true issue, the cost of repair would begin to outweigh the Tv's value.
