Thanks for all of your help, I'll let you know how I make out.

take care and have a great weekend,

Markus,

On Sat, 10 Sep 2005 21:04:28 GMT, "Mark D. Zacharias"
wrote:


"Cliff Top" wrote in message
...
The Yamaha monitoring circuit tests all the psu rails and therefore any
rail
going high/low in voltage by more than say 20% will cause the unit to
trip.
There are 2 severities however. If the power trips so rarely it'll be
difficult to know whether its the 1/2 sec (serious) or 3 sec (not so..)
mode.
I recently had a smaller Yamaha in recently with just this symptom.
turned
out to be a leaky diode causing a low -25v rail for the FDP drive. In any
other manufacturers unit the screen would be off (or dim as in this case)
but here it causes a trip.
The diagnostics don't really help with an error code of 16% reading for
the
psu rail... normal value 23%.... weird values but basically correct at
16/23rds of the rails normal value.
Your problem will doubtless be one of the rails but with so many you'll
just
have to test each in turn. Thats a bit tricky in the few seconds you get
I've also had a 5v reg go s/c so that 10v is put through to other areas
without tripping !!

Diagnostics is usually hold 2 buttons like set menu & prog+ on front
panel
then bring out of standby.
There are 2 diag modes, one where the protection is removed... this can be
very dangerous if you have a serious rail fault and could cause untold
extra
damage so needs to be used wisely.

If you need the pdf manual, I can send it when back off my hols..
regards
Andrew



Sounds like you're an authorized servicer as well. Where are you? I already
sent him the manual - he should have it by now.

Mark Z.
(Wichita, KS.)