[sdiy] 909 PSU modded?

[Synthusiast]

Hi list,

Lately I had some troubles with the Hi-Tom of my 909: it sounded very weak
and whit my amp turned high it sounded distorted. So I opened the machine to
find out in the first place that some changes had been done to the PSU
(traces of browned solder flux). It looked like the power transformer was
replaced, along with some caps and all three voltage regulators. I was
surprised to find a 7815, 7915 and 7805 in there, where normally Roland
mostly uses Japanese parts for their gear.

As I didn't have time to do a thorough error search, I fiddled a bit with
the connectors and PCB's inside, closed the unit, and powered it up to find
my Hi-Tom working fine again. So my guess is, that the cause was a loose
connector or a bad solder joint.

Still I have my doubts about the voltage regulators, especially after
reading some bad stories about them in the archive. Can anybody with a 909
schematic confirm that Roland used 7815/7915/7805 voltage regulators for
this machine? And if not, should I replace them with other, better ones?

Cheers,
Martijn