Pn64e8000 power supply

[tvtimmy]

I just ordered a used BN44-00516A power supply. I know they are prone to having cold/cracked solder joints, and I plan to spend a few hours touching them all up.
Should I remove all the white caulk like crap from the legs of the fets? I think 5 of them have it on them.

[JLCurve]

Re: Pn64e8000 power supply

Hi,

The silicon is there to mitigate dusty (smoker) environments. FETs handle relatively high voltages regarding to their gates. Dust can bridge Drain to Gate (and fry the fet). Silicon is there to mitigate cheap overall cooling design (no filter). Believe me, if Samsung could have done without the silicon smudges they would have! (in overall warranty repair costs)

My advise is not to look for problems before they appear.

Note that I don't know this particular model..

Cheers,

Curve514

[tvtimmy]

Re: Pn64e8000 power supply

I thought that over time the silicone turns conductive and will ZAP the igbt's and other things. I planned on removing it and replacing it with RTV black. It's used in the automotive field and great against heat.

[budm]

Re: Pn64e8000 power supply

It's the old brown glue that is corrosive and conductive.
I will not remove those white silicone unless you are going to replace the parts.
You need to use electronics grade Silicone RTV (they are not cheap, I.E. https://www.gordonglassusa.com/group...e-Silicone.htm, https://www.americansealantsinc.com/...rade-silicone/)
Read this about the type of Silicone RTV, if it smells like vinegar during curing do not use it.
https://electronics.stackexchange.co...mponents/32812

[tvtimmy]

Re: Pn64e8000 power supply

Thanks Budm. I will concentrate on the bad solder joints then.