Ps50q96hd

[sordids999]

hello guys

trying to work out whats wrong with this plasma front standby light just flashes but no picture

VA 207 volts VS 60 volts on the psu

tested the buffer boards for shorts but cant find anything wrong

any more ideas

[tw2005]

Re: Ps50q96hd

That'd be what i'd be looking foe especially upper buffer and also check ymain , 80n30w FETs usually short with a bad bufferunless there's a mainboard issue.

[tom66]

Re: Ps50q96hd

Check Vscan & Vset on Y-main.

Any panel glow at all?

Check LED on Y-main, can you see one lit up?

Is LED on control board blinking?

[sordids999]

Re: Ps50q96hd

Vscan is 094 cant find Vset ?
no glow from the panel
no LED is lit up on the Y-main
LED control yes is blinking
also i have a spare main board tried that but still the same

[tom66]

Re: Ps50q96hd

Vscan at 94V is bad, indicates possibly shorted Y-buffer. Does it change when Y-buffers are removed?

[sordids999]

Re: Ps50q96hd

buffers removed gives me 0.00

[tom66]

Re: Ps50q96hd

Does that make the LED light on the Y-main?

[sordids999]

Re: Ps50q96hd

no tom no LED light on the Y-main
but im confused just tested the buffers again to be sure cant find any shorts ?

[tom66]

Re: Ps50q96hd

I'm not sure why the Vscan is going away when you pull the buffers. If you power-cycle the TV can you test it quickly on volt range, see if it spikes up then turns off maybe?

[sordids999]

Re: Ps50q96hd

0.34 volts with buffers removed i had my meter set at 600 volts turned it down to 20 volts and thats what i get now on V-Scan

[tom66]

Re: Ps50q96hd

Not really sure what to make of that but definitely something wrong with the Y-main. I second tw2005's suggestion to check for shorts on the transistors etc.

[sordids999]

Re: Ps50q96hd

ok ill check them

thanks

[sordids999]

Re: Ps50q96hd

tom question do you still think the buffers are no good before i test Y-main for shorts ?

[sordids999]

Re: Ps50q96hd

update :

upon inspecting the Y-sus further i noticed a blob of solder has blew off on one of the mosfets and the fuse on the Y-sus had blown so i re-soldered the connection and replaced the fuse and now the tv relays just clicks from the PSU and the tv keeps restarting,the fuse on the ysus is still fine ?

thanks

[tom66]

Re: Ps50q96hd

Suggest you check Vs on Y-main for shorts. Bet the 88N30W's are shorted...

[tw2005]

Re: Ps50q96hd

update :

upon inspecting the Y-sus further i noticed a blob of solder has blew off on one of the mosfets and the fuse on the Y-sus had blown so i re-soldered the connection and replaced the fuse and now the tv relays just clicks from the PSU and the tv keeps restarting,the fuse on the ysus is still fine ?

thanks

You may have more than one fault. PSU continually clicking may suggest the Vs / va ccts have now blown on the PSU.

if they have not blown, may be an idea to reflow the fets on the heat sinks on the PSU.

i've got one of these that has blown upper buffer, blown the ymain & has blown the the vs and Va lines on the PSU and continually clicks.

3 most common faults with that series are those 3 items. AFAIK the PSu repair is not just a case of replacing the FETs, there's a bunch of SMD transistors and diodes etc underneath that go too. Not sure but they do get dry/fractured joints on the FEts and i suspect that is when the PSU blows.

Maybe some pictures of the ymain blown solder issue would be handy as that sounds unusual.

[sordids999]

Re: Ps50q96hd

Tom:

just tested these and im getting no reading just beeping from the multi meter

http://www.ebay.co.uk/itm/4pcs-RJH30...item417a383662

picture updated

[sordids999]

Re: Ps50q96hd

@Tw0025 Q5101 middle pin had the blown solder when i inspected it