You need to do the current sharing test that is called out in the manual. The issue I have with using old outputs is you don't know what kind of thermal stress and load faults they've seen. When one output fails it is likely that the others that were in the same stack were pretty hot and may have also seen a high fault current. The weakest one failed but the others may have been close.
The burnt resistors on the output jacks are a sign of oscillations. The manual addresses this and offers some solutions.
The Dale 250 watt load resistors are expensive. I see Parts Express has some 100 and 200 watt reasonably priced. If your budget doesn't allow for the 200's the 100's will be OK, you would need to limit full power testing to a short time. the 700 would certainly tax 100W resistors.
To do full load testing, you need 8A fuses.
I recently rebuilt a 400 that had been beat up pretty bad while bouncing around in a PA rack. I had to build a new face plate and the meters were not usable. I'll post a pic when I can get to it.
The burnt resistors on the output jacks are a sign of oscillations. The manual addresses this and offers some solutions.
The Dale 250 watt load resistors are expensive. I see Parts Express has some 100 and 200 watt reasonably priced. If your budget doesn't allow for the 200's the 100's will be OK, you would need to limit full power testing to a short time. the 700 would certainly tax 100W resistors.
To do full load testing, you need 8A fuses.
I recently rebuilt a 400 that had been beat up pretty bad while bouncing around in a PA rack. I had to build a new face plate and the meters were not usable. I'll post a pic when I can get to it.
