Theoretically you could do it yourself. BUT!!! These aren't unit's that you would learn on. I don't want to dissuade you from it but once you look inside you'll see what I mean. The 400-CX2 is really crowded and should be sent to a shop for work on any scale unless you have tube experience. The SA-300 isn't that crowded but all of them are INTERMEDIATE to ADVANCED level units for hobbiest repairs. Don't mess with the tuner. Leave it to a shop. If you want it done right the 1st time and by someone who knows the 400C and CX/CX2 intimately, then send it and the SA-300 to Dave Gillespie. He's in Atlanta area so shipping ain't gonna be cheap. He'll also be able to set up, and align the tuner and multiplexer using a FISHER 300 tuner and Multiplex alignment rig.
Check around the AK site and find a couple guys from the BAY AREA who have Tube Testers. Get the tubes all checked 1st before you do anything else.
rufleruf is in Oakland. I think he has at least one tube checker. He might know someone closer to you even. Mark the tubes with a piece of masking tape and the position of each on the tube position page in the manual. Make a list with the chassis' separated. Tuner is V1 thru V10, PREAMP is V1 thru V10, and the AMP is V1 thru V8. put that chassis's tubes in a ziplock bag with TUNER, PREAMP, or AMP marked clearly on the bag. If the guy comes to you, then pull each chassis and line them up on a towel on top and mark them with tape and put V1 thru V? on each tube. Do for all chassis. The Multiplexer chassis is the 3 tube chassis in the front center of the tuner. The tubes are V100-V101-V102. Put these 3 in a separate bag. Pull one tube at a time, test and put back in socket. Then do the next one. IF ANY show a WHITE GETTER it's DEAD, open to atmosphere, and a new tube is required. Make a note as to tube number and type (ie: 5ar4, 12ax7, etc.)
There should be a couple of guys in the Bay area(I'm in Baltimore so don't know who for sure) who are AK'ers that could possibly take a look at the SA-300, the CX-2, and maybe the R-200 just to make sure they are safe for you to start it up and play (with you in room with unit). They might even be able to take them on for you. Be a bit less expensive than a shop for a complete restoration. Figure on 2K for complete restoration on all 3 in a shop. Somewhat less for an AK'er. Dave might be cheaper too, but he's the acknowledged FISHER MASTER here on AK. You can have the shop just check it out for operation and repair what's not working also. But the units will need a complete restoration shortly down the road.
Tom ISHIMOTO is in SIMI VALLEY. He does really good work. Check with Vendo81 on his work. I think he's sent a couple pieces to Tom.
PACIFIC STEREO (that's his handle) is in the high desert near Edwards. He does excellent work. You can get his info on
www.tapeheads.net.
Terry DeWick is in Knoxville area but he's concentrating on Macintosh stuff lately. So He's out.
I've run out of names (or working brain cells).
Larry