On 7/9/2020 5:14 AM, JC wrote:
Fixing A Matsusada RK20-20 power supply.
2x devices blown on the primary switcher circuit
only id is code 00.15.0600 TO3PN3 case

https://www.flickr.com/photos/40466580@N07/

I'm thinking these are IGBT's rather than Mosfets but guesswork as they
are wrecked.
Any ideas? Code might indicate 15Amp 600Volt? feeling lucky?

Small driver board is encapsulated in RTV silicon goop, hopefully not
damaged but haven't got that far.

TIA JC


It could be my imagination but there seems to be some characters
printed on the more lightly coloured rectangle. If you have a
powerful lens with you, see if there's anything to read by
varying the angles of viewing and lighting. Perpendicular is not
always the best.

I use a lens salvaged from a 16mm film projector and have often
succeeded in identifying devices that at first don't seem to have
anything on them. That includes markings that had been rubbed
off, faded with age or burnt away from overheating.