Problem with manual release on dbx 165

[Honky]

I just purchased two dbx 165. Both are in excellent working condition except the manual release one one unit is not working properly, in that adjusting the potentiometer does not change the release time. In auto mode everything acts as it is supposed to. Is there a particular IC for the manual release that I should swap out?

[TLH]

Hi, I don't mind helping out if I can, but as you can see nobody wants to answer my question along the same lines. I have been inside of my unit for about a week now and have pretty much figured out what to do to fix it. First, the main trouble spot in these are the electrolytic caps. Check ESR on all of your electrolytic capacitors. Next, check the potentiometers themselves. Track the input and output traces from the release pot. Also, if you have a leakseeker, you can trace all the components on that trace for shorts. Check the trace with your DMM first to narrow your search, then track with the leakseeker. If you don't have a DMM and ESR meter, or scope don't even try to figure out one of these boxes. They are not simple. The good news though is that from your post at least its not the VCA which is getting really hard to find along with the film caps, and transistors. The BC 479 has an NTE replacement, but its not the same quality. Also, remember you are tracing signal, so don't get confused with the voltage checks. The small signal transistors should be checked next. You could check them in ciruit with a cricket if you can get to the leads or from behind the board.
Finally, after all of the above checks, you can sub in a replacement IC. On these boards though, its almost never an IC. There was a tech on the forum
that really knows these boards, but I couldn't seem to get his attention. It would really be good if we could both rap with Keith. My problem turned out to be Q10,Q11 and 12 shorts from a failed 1uf cap in line with op amp 4. Best of luck, tlh

[Ike Zimbel]

Originally Posted by Honky

I just purchased two dbx 165. Both are in excellent working condition except the manual release one one unit is not working properly, in that adjusting the potentiometer does not change the release time. In auto mode everything acts as it is supposed to. Is there a particular IC for the manual release that I should swap out?

I have one on the bench with a similar problem right now. Try fiddling with the "Master/Slave" switch on the front panel. If that helps, try cleaning the switch with some CAIG F-5 or similar. If it gets better, you're done. If not, you may have to replace the switch, as I am about to do with the one I have here.
Follow up: replacing the Slave switch and the Auto switch has corrected the fault in this unit and a 2nd unit, too. I have both switches in stock, BTW.
Best,
Ike