Hi Guys,
so a while back (2yrs) we had a power surge at work, 42inch LCD killed. I thought I'd take it home and try and fix it rather than chuck it in the bin. over the last 2 years I've gradually tried to fix it and I'm sooooo close now. after opening the back of the unit there was a whole lot of popped caps on the power supply. first idea was to replace the popped caps. this didn't make a difference. unit still had no power. months later I searched on good ol fleebay for the power supply unit (by model number). found stacks of them so just bought one. now when I put it in, I noticed that even though the 2 power supplies had the same model# they were different !??!!?!?!?!. the new one I bought were missing 3 pins for the output plug. 2x +5v and a +12v. but with this one the unit at least had power but wouldn't turn the screen on.
so today, I checked the front/back of both boards. on the old one, the extra pins are directly connected to the others (of the same value). no other components inbetween. so I thought I'd try connecting a few wires between them on the back side of the plug. hey presto it worked!!! tv powers on, display on screen only problem now is there's a constant buzzzzzzzzzzz from the built in speakers. now I dont know if this is caused by my "fix" or if it's because of the power surge back when the TV was first killed. I had thought I'd just disconnect them and run speakers through the aux output. but what do you know there's no aux out. so if I can't get rid of the buzzzz it means I cant use the built in HD tuner.
so far though I've got a working full HD 42" LCD that I can use any of the other inputs on, just not the built in HD tuner
can anyone suggest ways that I can test/isolate the issue that's causing the buzz through the speakers? the buzz doesnt increase/decrease with the volume control if that helps...
so a while back (2yrs) we had a power surge at work, 42inch LCD killed. I thought I'd take it home and try and fix it rather than chuck it in the bin. over the last 2 years I've gradually tried to fix it and I'm sooooo close now. after opening the back of the unit there was a whole lot of popped caps on the power supply. first idea was to replace the popped caps. this didn't make a difference. unit still had no power. months later I searched on good ol fleebay for the power supply unit (by model number). found stacks of them so just bought one. now when I put it in, I noticed that even though the 2 power supplies had the same model# they were different !??!!?!?!?!. the new one I bought were missing 3 pins for the output plug. 2x +5v and a +12v. but with this one the unit at least had power but wouldn't turn the screen on.
so today, I checked the front/back of both boards. on the old one, the extra pins are directly connected to the others (of the same value). no other components inbetween. so I thought I'd try connecting a few wires between them on the back side of the plug. hey presto it worked!!! tv powers on, display on screen only problem now is there's a constant buzzzzzzzzzzz from the built in speakers. now I dont know if this is caused by my "fix" or if it's because of the power surge back when the TV was first killed. I had thought I'd just disconnect them and run speakers through the aux output. but what do you know there's no aux out. so if I can't get rid of the buzzzz it means I cant use the built in HD tuner.
so far though I've got a working full HD 42" LCD that I can use any of the other inputs on, just not the built in HD tuner
can anyone suggest ways that I can test/isolate the issue that's causing the buzz through the speakers? the buzz doesnt increase/decrease with the volume control if that helps...