Tek FG504 no workee

[audionautica]

My FG504 is sick.

When I turn the mainframe on, the signal is there for about a second and then disappears.
Failure then manifests itself in one of two ways :

EITHER - no volts at all on power rail test points
OR - +25 and +15 is present, -25 and -15 is not present.

DCR check on the rails does not indicate short to ground, and have checked the obvious tants that I can see for shorts. Can't find any.

Very odd that there is a signal for a second or so on power up and then it disappears.

Any ideas where I should start?

PS - No, I don't have extenders, however I can slide the side off my TM5006 which allows me to access quite a lot in situ.

[Roehrenonkel]

Hi audionautica,
 
is the problem on all six slots?
Maybe one of the external transistor for the psu-reg went bad.
Check the slot-contacst also.
Are all electrolytics good??

Good luck