Altec 1612a - No Output on meter and no sound? Help

[TheQuestForTone]

I picked up an old Altec 1612a and am trying to revive it. The first 1588b preamp I got had a broken guide pin, and I didn't realize this until I turned the unit on. If it was in the wrong orientation could it have caused a voltage spike that messed up some components in the output section?

I bought a working preamp for the socket that now has a proper guide pin. It's now showing gain reduction when I speak into mic, but there is no sound output when I flip the meter to output.

Any ideas how I can troubleshoot this? Here's some pics of the inside.

 

[TheQuestForTone]

Bump. Anyone?

 

[Ike Zimbel]

We would need way more information to help you with this. Things like:
-what, if any, test equipment do you have?
-did the unit ever work for you, or did you acquire it in non-working condition?
-what is your troubleshooting experience / skill level?
-and so on...
I'm afraid this is way beyond a "If it doesn't work, do this!" kind of fix.

 

[TheQuestForTone]

We would need way more information to help you with this. Things like:
-what, if any, test equipment do you have?
-did the unit ever work for you, or did you acquire it in non-working condition?
-what is your troubleshooting experience / skill level?
-and so on...
I'm afraid this is way beyond a "If it doesn't work, do this!" kind of fix.

I have a multimeter. I'd say I'm intermediate at fixing stuff. If I know what component is messed up I can remove and replace. I'm just not super good at diagnosing the problems. It worked when I got it, but when swapping the preamp socket I think I inadvertently fucked up the voltage because the socuket pin was broken, so I think I plugged it in where it sent some voltage down the wrong path. I was getting output before that. So I'm sure I fried something. Nothing appears fried from looking at it.

The vu on the input registers so I guess the signal is making it through the circuit partially. Any suggestions?

 

[TheQuestForTone]

bump

 

[C.B. - Boudio]

You could try to use a signal tracer and see to where the signal gets.

 

[TheQuestForTone]

You could try to use a signal tracer and see to where the signal gets.

great idea. I don't have one. could you recommend a quality signal tracer to user?

 

[C.B. - Boudio]

Well, I just use my oscilloscope as such, because I don't have an actual signal tracer (sounds more like a luxury problem than it probably is).

 

[My3gger]

You could use DAW for generating signals, then trace them with DVM.