Thanks for the reply.  It's not confirmed that the supply I'm using works (haven't tested it with another 707.)  It's a selectable voltage power supply.  I have it set at 12 V DC with negative center.  It Is 300 mA but a I thought that as long as its amperage was higher it should be okay.  I can trace the 12 V to the switch, then when I turn the switch on I read about 4 V at both test points where I should be getting +5 and -10.  It also oscillates, like it rises from about 1V to 4V and back again quickly.  I tried replacing all the caps and the 5V regulator but that didn't work.  Could it be something further down in the circuitry or would that not affect the power supply section

Thanks for your help