Madrigal Proceed PAV Schematics

I have a Proceed PAV (the one with button volume control instead of knob) that I inherited from my uncle. I was using it just for 2 channel listening. It started shutting itself off intermittently when I adjusted the volume level. Now, when I power it on, all of the lights go on for a second, and then blank and then I hear a regular clicking sound. I assume that's a relay. Any advice on this issue would be appreciated.
But I am also looking to obtain the schematics or service manual for this component. Madrigal Labs is out of business, and I can't find any contact info for Madrigal/Mark Levinson on the Harman International website.
Wow, this PAV is from 1995!!   When stuff gets this old, it's very typical for the electrolytic caps to have dried up and will not contain capacitance charge.  This, in turn, will not hold that relay on.  You want somebody to replace those caps.  The following link has a large number of PAC pictures:

The "pav-b.jpg" picture shows the power supply board specifically.  I can't see anything that might be a relay, but you would probably want to re-cap the entire board.  If you're getting this work done, it's probably worth it to recap the entire unit.
Wow! Thanks so much, auxinput. I'll let you know how we get on. I'll have to price out recapping the entire board and then make a decision, but I would love to. This is by far, the best sounding pre-amp I own. By which I mean transparent. I didn't even understand what that meant until I plugged this into my system.
Are you planning on doing the re-cap yourself?  Or having somebody do it?
A local shop is doing the work. Not retail, just a repair shop fixing hi-fi and musical instruments, who are attached to a practice studio. They have done good work for me in the past, and I trust them.
You may not have any control over what choice of capacitors they use in the PAV.  I know some of these older equipment used specific brands/models of capacitors to get a certain sonic signature.  If they are just a hi-fi / music repair shop, they may use the cheapest capacitors available for a generic "fixit" solution.  It may change the voice of the PAV.

For what it's worth, I have found the Nichicon KZ caps to be the absolute best for a smaller size cap (1000uf or under).  These are absolutely excellent, but they are larger in physical size and will often not fit into a specific location.  It's often worth it to try to shoe-horn in these caps even if they are sticking out with 1/2" of lead.

For places where the KZ caps can't fit, the Nichicon KW caps are the next best thing.  You will probably have to use KW for the big main power supply caps anyways.

If your repair guy can identify the "standby power supply section", then I would advise using something like the Nichicon PW caps, or something that has a long life (such as 5000 hours at 105 degree).  These definitely don't need the KW/KZ audio caps.
Wow, thanks again. I will pass this info along. Unfortunately, without the schematics and electrical signal paths and values, the tech says it would be expensive were he to engage in trial and error, and he couldn't guarantee success. I'm going to spend a few days tracking down leads, before I give up.
Sure, I could send it off to a fancy shop in Colorado or Seattle, but it's much more fun to do it hard (and cheaper) way.
Yeah, he is probably right.  It is most likely the capacitors that need to be replaced, but it could very well be something else.
IIRC I bought my PAV probably in the '80s.  It and a matching stereo amp replaced my Marantz 18 receiver.  Five of those amps, the PAV, and the 18 are sitting in a rack, unused for decades.  The PAV was replaced by a Cary Cinema for HT, then a Parasound JC 2 BP and Bryston SP3, and now an Ayre KX-5 Twenty and the SP3.  The Cinema and JC 2 BP are in boxes.  I've been remiss about not selling stuff.