Akai CR-80D-SS

I finally scored one of these in April of 2019. It's one of the more sought after 8-track decks either in 2-channel or 4-channel, and being a quad person I'd always wanted one. I saw this one on an online auction and was the successful bidder. While they are built as solid as can be, I never get my hopes up until I get them on the bench. Mechanically and cosmetically this arrived in good shape. I gave it the standard cleaning and lubrication but the one thing I didn't have to do was replace the belt. That item is heavy duty, similar to ones I've seen in vacuum cleaners.

The downside is that it has electronic playback issues. Some of the channels appear to be dead. This could most likely be one of two things: a switch or a dead integrated circuit. There is one of those long switches with 20-some contacts on one of the boards and I gave that a good cleaning and had a couple channels working but one, front left if I remember correctly, just wouldn't go. Based on what I read online, the amplifier circuit could be the problem and the integrated circuit that is the likely culprit is no longer available. So, what folks do is to build the circuit out of sepearte components (transitors/resistors/capacitors) on a breadboard and wire that in to the deck's circuit board in place of the IC. OK, I'm game, so I ordered the parts, enough to build 4 of the circuits, and had a go at building one. I got it in place and there is no improvement. Hmmmm....that leads me to believe that I did something wrong in the constrution or the IC isn't the problem.

I got pretty busy with some other work so this has been put aside. The more I think about it the more I am going back to the switch issue. It is difficult to get to and I just may not have delivered the Deoxit to it enough or had not exercised enough after that. My plan is to get the deck back on the bench, put the IC back on the board and return to solving the switch problem. After all, one of the channels that worked before I started this did not work after I put my breadboard in place so I must have jiggled something.

Below are some photos of it in various stages of undress.

Click on an image to enlarge it.

Updated December 2020.