e-studio 230/280 power supply repair

[ezzysi]

Hi all,
i've got 2 faulty power supply boards that i'd like to repair, there both from machines that had the fuser lamp wire trapped after servicing and subsequently blew the psu.
Ive replaced the 10a fuse on the board but the machine only powers up for a few seconds then switchs off by itself..... a new psu solved the problem but i'd like to repair the old boards if possible.
I've heard this is a common problem and that theres an easy fix???
any ideas?
Cheers
Simon

[tsbservice]

Replace all triacs.