Hi, I'm a bit of a novice when it comes to these things but I have done some research and it seems one of the pico fuses has blown, the Tv turns on but gives no picture, it has sound but no picture. I have a basic digital meter and have tested all voltages, they all seem fine so I can discount the PSU, the X board(far right) gets very hot with a healthy buzz so I'm sure that's working fine, the Y-SUS on the other hand doesn't, but you can still hear a gentle buzz, all ceramic fuses have good continuity, there's also another soldered to a small control board bottom right of the YSUS and that seems fine too. I've tested all pico fuses and only one shows any kind of abnormality, I used the diode test on the digital meter and from a base reading of 1 it dropped down to about 0.7, all other fuses dropped right down to zero so that suggested to me that this one had blown open, now my question is why has it blown?
To give some back ground on the Tv, I was given it with the previous owners description that the picture started to drop out after a few hours use, then progressively over time that time frame dropped to about half an hour at which point it wouldn't produce a picture again, it does turn on and seems to react to the remote, indeed when trying to display the menu a louder buzz can be heard, then when switching off the buzz becomes less obvious so that would suggest the main board is OK, at least in my opinion.
I've tested the eight MOSFETs(I presume that's what they are) using the diode mode on the DMM and found all eight showing the exact same reading, dropping from 1.0 to 0.405 on each of the bottom pins, middle pin seems to be cut off and top pin stays the same @1.0, this might suggest all are fine but I don't know, I shall be changing the pico fuse and hoping it's just simply that that's at fault, but considering it's a fuse something has probably caused it to blow, just not too sure what so any help would be greatly appreciated, thanks, Andy.
To give some back ground on the Tv, I was given it with the previous owners description that the picture started to drop out after a few hours use, then progressively over time that time frame dropped to about half an hour at which point it wouldn't produce a picture again, it does turn on and seems to react to the remote, indeed when trying to display the menu a louder buzz can be heard, then when switching off the buzz becomes less obvious so that would suggest the main board is OK, at least in my opinion.
I've tested the eight MOSFETs(I presume that's what they are) using the diode mode on the DMM and found all eight showing the exact same reading, dropping from 1.0 to 0.405 on each of the bottom pins, middle pin seems to be cut off and top pin stays the same @1.0, this might suggest all are fine but I don't know, I shall be changing the pico fuse and hoping it's just simply that that's at fault, but considering it's a fuse something has probably caused it to blow, just not too sure what so any help would be greatly appreciated, thanks, Andy.
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