svt expert question

[phsyconoodler]

I have an SVT bass amp(vietnam made) on the bench and it blew one tube.I replaced the tubes and replaced the 220 ohm resistors on the output board as needed.However,it does a funny thing: the bias sense lights come on green when it is still in standby.You turn the main switch on and it lights up those lights.Then when you flip the standby to on,it flashes in protect mode.
  There is a large relay on the power inlet board,a 16A/250VAC relay that is connected to one end of the standby wiring.I think that relay may be damaged but Who knows?These amps are complicated beyond belief for this lowly tech!
 Any insight into this circuit would be appreciated.I can simply throw in another relay but it would be nice to know if that may be the issue here.

[xm52]

Is the amp an SVT-VR? If so, there is a known issue with low power putting the amp in protect mode. This causes a lot of frustration for players at gigs where the line power can be low. There is a simple fix that bypasses this feature and doesn't harm the amp. Here are the details: http://johnkvintageguitars.homestead.com/SVT-VR.html

The tubes on an SVT are matched in trios. If you replaced a tube and its performance not up to spec, the amp's bias circuit will complain.

Since there was an issue with the 200 ohm screen resistor(s), I would check the plate resistors while you are in there.

[phsyconoodler]

I bypassed the standby like in the article and it works now,just have to pop in the new tubes and see what happens.Another one of the old tubes shorted out,so it was definitely a good plan for all new ones.
  Man these amps are expensive to service!!!

Thanks for the links and info guys!!! It is greatly appreciated!!!