Tascam 122mk2 Transport Overhaul Tests

Testing the transport overhaul and record head lapping with close up operation views.

[penelec]

Amazing! I am in awe of your work and grateful you take on this work. Looking forward to putting it back in service!

[Test-TapeFull-track]

Hello Peter! Yasou! The device produces very good results! In fact, this is not much distortion at such a high overdrive recording level! Continue to amaze with such interesting videos! Thank you!🤝🤝

[Magnetonband]

Thank you for providing such helpful high quality videos about our beloved oldies! I also got a 122MKII from a broadcaster some years ago and of course had to change idler tiers, the belt, and capstan board caps. I also replaced C134 and C136 next to the mainboard's red power supply socket for the control board. The 100µ had only 40µ left and both were mounted with wrong polarity straight from the factory. Also the labelling on the PCB is wrong. The result is slight hum and a strange behaviour of the counter - especially when you insert a cassette, due to the current peak when the capstan starts rotating.
My deck also has another issue: during PLAY the MECHA motor tries to lift the headblock to the tape tough it is already on the top position. The comparator voltage on U507 never gets so low that the motor stops spinning. Probably someone put the plastic joint on the 10k pot delivering the voltage proportional to the headblock height at the wrong position (the pot itself is fine). Maybe a 122MKII owner is able measure the voltage on P503 pins 1 and 2 during PLAY (which is the voltage for the MECHA motor)? I'm curious whether it's really 0V or whether the designers wanted to give the motor a litte torque during PLAY so that the mecha block is guaranteed to be fixed at the top position. On tapeheads.net / Cassette I put a topic with a photo where to find U507 and P503.
Thank you again 👍👍👍

[douro]

So you put actual audio tape in your mirror cassette...these things typically have a green coloured film strip in them.

[rcary]

I like the mirror cassette. Are those hard to come by?

[PeterCreed-gs]

Do you back lap heads and service other cassette decks😊