Hi all,
I picked up an LG 32" lcd tv from a tv repair business, I don't know the repair history of the unit or what was wrong, the owner of the business simply said to me if there's anything at the back of the workshop then I could have, so managed to pickup 2 plasma's of which one still work and the above lcd.
I've taken the back cover off and checked for any obvious popped caps on the main power board 6871TPT303B,and couldn't see anything out of the ordinary to my untrained eye, I then connected the power and virtually immediately the back lights came on and I could also some light on/in the screen, a point to note, I got the impression that the on/off is somehow by-passed as when push the switch it doesn't seem to control the on/off function.
I unplugged to power and took the main powerboard off to check for dry/cracked solder, on the underside on the pcb there has been a modification (see the pictures below) there has been a 50v 22uF cap attached to two legs of IC103, it appears a piece of the pcb track has been deliberately removed to accomodate this modification.
The other modification is a 2 x resistors that has been attached to the G leg of a power mosfet.
There were a small handful of dry/cracked solder joints of which I refreshed, I then re-connected the board and powered up, a slight difference occurred this time, previously the backlights would on immediately but now there is a defernate delay between when the power is connected and the backlights come on and still the front power switch doesn't appear to control the on/off function.
any advice is greatly appreciated as I hope this has made sense.
I picked up an LG 32" lcd tv from a tv repair business, I don't know the repair history of the unit or what was wrong, the owner of the business simply said to me if there's anything at the back of the workshop then I could have, so managed to pickup 2 plasma's of which one still work and the above lcd.
I've taken the back cover off and checked for any obvious popped caps on the main power board 6871TPT303B,and couldn't see anything out of the ordinary to my untrained eye, I then connected the power and virtually immediately the back lights came on and I could also some light on/in the screen, a point to note, I got the impression that the on/off is somehow by-passed as when push the switch it doesn't seem to control the on/off function.
I unplugged to power and took the main powerboard off to check for dry/cracked solder, on the underside on the pcb there has been a modification (see the pictures below) there has been a 50v 22uF cap attached to two legs of IC103, it appears a piece of the pcb track has been deliberately removed to accomodate this modification.
The other modification is a 2 x resistors that has been attached to the G leg of a power mosfet.
There were a small handful of dry/cracked solder joints of which I refreshed, I then re-connected the board and powered up, a slight difference occurred this time, previously the backlights would on immediately but now there is a defernate delay between when the power is connected and the backlights come on and still the front power switch doesn't appear to control the on/off function.
any advice is greatly appreciated as I hope this has made sense.
Attached Files
