I'm having some fun with a 60PH670S plasma TV.
Originally no display Y-Sus (60R5-Ysus) board shorted.
Found 3 shorted IGBT's on sustain output (Q402 on high side, Q559, Q564 on low side), MOS Q509 on set down and R251, D603.
My usual supplier didn't have any of the original references. I substituted TK8A60DA for FCPF11N60.
Supplier suggested RJP63K2 as a substitute for original RJP30H2A, not having found anything closer available I followed this route.
All 6 IGBT's (including the 3 that survived) were replaced for better current sharing.
TV is now working but low side IGBT's get very hot. Thermal camed at 110°C through PCB for the hottest after 5 minutes running so I'm quite concerned about the junction temperature...
Although the datasheets I've found don't mention internal diodes, the substitutes seem to have one while the originals don't. There are freewheel double diodes on the PCB (SF20D400SD2).
Are the internal diodes a good enough reason for the high temperature? They could could have a lower Vf than the external ones and dissipate extra power, the VCE sat is also slightly higher.
I feel it can't be left as-is and relaible, but feel a little stuck for solutions other than lowering thermal resistance.
Any ideas?