LG 50PS3000 Sound but No Picture

[NipZ]

I bought this LG 50PS3000 as faulty, Sound but no Picture(I can hear radio stations). When I purchased it the guy I bought it off said that a friend had looked at it for him but didnt get it working. He said his friend had adjusted voltages.
When I inspected it I noticed a blown main fuse on the ZSUS that had been bridged so I purchased a brand new board and replaced it. Unfortunately the TV is still not working.
I checked the VS and VA (preinstallation of the new ZSUS) which were both high, VS should have been 195v but was over 200v, VA should have been 65v but was approx 70v which were both above the maximum recommended. I assume these are the volatges his friend adjusted.

How can I troubleshoot what is at fault now?
2 Green LED's are visible on the Ctrl board, one solid the other gives a sequence that repeats itself
I checked fuses on the ZSUS which all appear ok apart from a pico fuse that on a continuity test gives me a very brief beep and then nothing asthough it is open, leave it a minute test again and the same result a brief beep and then nothing. When tested while the TV is switched on I do receive a continous beep

[selldoor]

Re: LG 50PS3000 Sound but No Picture

I know very little about tvs but fuses tend to be good or they are not.
Resettable ones are the exception.
Take the pico fuse out and ohms test it.

[freakaftr8]

Re: LG 50PS3000 Sound but No Picture

Ok that fuse is running voltage to your bottom x drivers. Replace it. That fuse is on the ysus btw. Start there.

[tom66]

Re: LG 50PS3000 Sound but No Picture

70V on Va can damage the plasma panel, make SURE to set that back before firing it up or good bye panel!!!

[NipZ]

Re: LG 50PS3000 Sound but No Picture

Ok that fuse is running voltage to your bottom x drivers. Replace it. That fuse is on the ysus btw. Start there.

The fuse on the YSUS is 125v 4A, can I replace it with a 250v 3.15A?

[tom66]

Re: LG 50PS3000 Sound but No Picture

Yes, but it could blow earlier.

[NipZ]

Re: LG 50PS3000 Sound but No Picture

Thanks Tom, I'll try the 250v 3.15A as I have a few of them knocking about

[NipZ]

Re: LG 50PS3000 Sound but No Picture

I removed the original fuse in questions and it tested open. I replaced with a 250v 3.15a fuse, everything tested ok while the tv powered off but once I powered the tv on(still no picture) and back down the new fuse gave exactly the same results as the original fuse. I removed the replacement fuse and again it tested open.

Any ideas what the cause could be or what I can try or test?(limited knowledge but willing to try)