Panasonic TNPA5335 YSUS Difficult Fault

[foxyUK]

This board has had a hard time due to fake components (I've fixed 3 since without issue, using good IGBTs, but this one is very sick still).
All IGBT's have been changed, and many other components. All IC's pass a diode check as given in Panasonic fault-finding guide, and everything else seems the same resistance as a good board, but the picture is as per the attached clip. May not be obvious on the clip but there is some image retention. This was intermittent for a while, but now solid.
Vscan, Vad and Energy recovery volts are all OK at 147v, 200v (to Vfg) and 113v (to ground).

Any ideas anyone?



Thanks!!

[foxyUK]

Re: Panasonic TNPA5335 YSUS Difficult Fault

Ok... couldn't attach a short video clip, so back to a link!

https://photos.app.goo.gl/aF6HHWnbWkwR15Ja9

[tw2005]

Re: Panasonic TNPA5335 YSUS Difficult Fault

Honestly don't know, out of the loop now but what's th efull history? sevearl attempts by yo or before you? is the ysus correct version for this model TV?

[foxyUK]

Re: Panasonic TNPA5335 YSUS Difficult Fault

Honestly don't know, out of the loop now but what's th efull history? sevearl attempts by yo or before you? is the ysus correct version for this model TV?

Sorry for the delayed response TW and thanks for looking!
It's the original correct board. Fake components for the first attempted repair made things worse and it was all downhill from there. Eventually a repairer got it working properly but after a short run it degraded to how you see the video. Initially intermittent, then hard.

[Nick's Tvs]

Re: Panasonic TNPA5335 YSUS Difficult Fault

If you could also let us know which parts you have attempted to replace or have been attempted to be replaced as well.
Also are you getting 7 blinks, are you getting 6 blinks?
Sometimes when using fake components, they can break other parts of the board as well and change the error code to 6 which then means you have a lot more work to do.

[foxyUK]

Re: Panasonic TNPA5335 YSUS Difficult Fault

If you could also let us know which parts you have attempted to replace or have been attempted to be replaced as well.
Also are you getting 7 blinks, are you getting 6 blinks?
Sometimes when using fake components, they can break other parts of the board as well and change the error code to 6 which then means you have a lot more work to do.

Hi 'Nick'..
The usual 6 IGBT's were changed along with IC501,502, and the little driver pairs. When the fake IGBT's blew, those had to be changed again, along with IC521, Q521and I also learnt later that usually only the IGBTs blow on this board. After much checking and measuring, ICs 784 and 786 were changed and this brought the board to life but with the poor images that you see in the clip. However, without changing anything, handling and refit of the board made it work properly for a while, before going faulty again. I have searched for bad joints and cracked tracks until my eyeballs hurt, but don't find anything, and no amount of prodding will restore function. All active components have been 'diode checked' against values from a good board and the Panasonic guide values, and are OK. Voltages are OK. There are no blink codes...it runs. This board is effectively a spare, as I bought enough dead TVs to get the boards I need, but it remains a challenge that niggles me. Ultimately it might just have to be a board for donating components.