Sony TC-161SD repairs.

Colin phoned

"My mate Susie's got a Sony Amplifier only working on one channel, care to take a look?"

Yeah... why not.

It's a Sony TA-1055. 

It was the world's easiest fix. A noisy tape monitor switch, which, after a few operations put itself right.

Susie also has a Sony TC-161 SD cassette deck. 

It's a top loading deck dating from 1972. 

This one doesn't play or record... Let's have a look...

We need to get in from the bottom. There are 6 screws, some recessed, in the bottom panel. This enables us to remove (after a bit of wiggling) the plastic bottom, and wooden case in one go.

This machine is lacking take up, but rewind and fast-forward work after a fashion, although at a somewhat leisurely pace! The fault's are bound to be mechanical.

The machine is able to detect movement of the tape using a small hall sensor, located on the pulley which is fed from the reels, and eventually leads off to the tape counter. If the hall detector stops seeing tape movement, it engages a solenoid, which stops the mechanism. This is how the autostop mechanism works.

Whilst the belts aren't in great condition, they are working, but are replaced anyway. The small idlers (there are three, one take up, one rewind and one fast-forward) are cleaned up with rubber rejuvenator, but are in remarkable condition. 

Now we have great rewind and fast-forward, but still no take up, which the autostop mechanism detects and stops the deck before our cassette is a mangled mess. The take up idler is not engaging. 

Sadly, it's rather buried under one of the capstans (This is a two capstan deck). You can just see it beneath the large grey capstan flywheel. 

Some disassembly is required...  

Removal of the capstan and flywheel gives us good access. 

The idler swivels into position, and tension is applied by a spring to engage it between the capstan and the take up clutch.. except it can't as the joint in the arm has seized solid. A little application of localised hot air from the SMD hot air soldering station frees it up, and when it's cool, a spot of oil is added. It now moves freely.

With everything reassembled, we now have all functions working... 

... except listening to the output, we've got very weak audio, and occasionally oscillation. Putting a blank tape in the machine and working the record button several times clears the fault. It's a tarnished record/play switch. A quick squirt of servisol helps. OK, we've now got playback but no recording. I can *just* hear audio, but it's very faint. Just as I'm beginning to suspect the record-play switch again, I switch Dolby off. Up comes record audio. Switch it back on and it's a bit intermittent. Another quick squirt of servisol to the dolby switch and all is well. I've also done the limiter, and tape selector switches as well as the record volume controls, just to make sure.