Studer A-80 repair

[jjgolden]

Hi

I have a Studer A-80R that I'm trying to get running.
My first issue:

When I turn on the power, The LOC and tape path lights are illuminated but nothing else is functional.
I took a reading from the +20 & +24v points on the Stabilizer card and they read 1.3mv and 42.2 mv respectively.
I checked the fuses in the fuse bay and they all have continuity.

Any help/direction from this point would be greatly appreciated.

Thanks!
JJG

[studiorp]

Check all capacitors electr., diodes, resistors, etc.

[jjgolden]

Ok thanks,
Will do the control unit cards first and repost any progress.

Thanks!
JJG

[ejemmons]

I'd check the pass transistors for the logic PSU, they're on the deck casting. Do you have a manual? I have two A80 multis, and they're pretty solid. Also the Frako electrolytics are probably suspect, simply due to age. I MAY have an extra manual for the A80-16, which would largely apply... have to look.

[jjgolden]

Thanks ejemmons,

I have a PDF manual for the A80RC MkI & MkII which should apply for this issue?
Mine is a A-80R (ML-5 / Mark Levinson) model. I think the only difference with the ML-5 is the audio electronics.

Pass Transistors: are those the 9 that can be seen from the back up under the deck next to the hanging caps?


Thanks for your input,
JJG

[ejemmons]

Yes, they are, and either manual should work. How about the other pwr rails?

[jjgolden]

Got it working!

It was a bad 220/25v cap on the Stabilizer card.
Thanks for the help & input!

JJG

[ejemmons]

Yay! I'd contemplate a recap of all electrolytics and tantalums. Did this on the 24 track, cured a large pile of ills in one go!

[jjgolden]

EJ,

Good to know! That'll be next on the list of to do's.
The Mark Levinson audio Cards are a little funky too.
They may not be possible to get into with their solid moulded circuit blocks. (copy protecting the design I guess?)

Thanks again!
JJG

[misjah]

for anybody repairing their A80, I have new logic and audio extender cards.

www.24mastering.com

cheers

Misjah