Life with Music - Early Restoration
In early 2020, right before the COVID lockdown, I bought my first cassette Walkman, the Sony WM-F1. It costs me $80 and it includes all the packaging and accessories (bargain!). The exterior looks gorgeous, but definitely need a repair inside, as the fast forward mech does not engage properly. I opened it up for the first time, and belts are warped due to a long period time of not using it, and the spring just fell off from the mechanism. I collected it in my pencil cases, and it was a four-year wait till I am confident enough to repair it again. Therefore I use it with just play and rewinds button, and served me well over these four years.
I bought another Walkman as backup -- Sony WM-F2015. It is a cheaper model compare to the WM-F1, and when I first got it the right channel is not working, and the sound is distorted. I have no experience in repairing those at that moment, so I sent to Retrospekt for a repair -- 80$ at that time, pretty expensive. Then I decide to learn how to maintain and repair a cassette player myself.
Over the next four years, I collected several Walkmans: Aiwa HS-PS120, Panasonic RQ350, Toshiba KT-4252, and FiiO CP-13. I bought them for learning how different mechanism works to prepare my repair. I bought service manual for each one of them (except FiiO because that one is brand new with warranty). Each one have its unique sound signature, and I enjoyed with all of them.
I did my first repair job for the RCA SCT-86 cassette mini deck in our photo lab. It was missing right channel, and the speed is too slow compared to the reference. So during the beginning of fall quarter, I found a way to fix this problem, thanks to the video from VWestlife, which I need to use a jumper wire for routing the signal from the audio chip to the output. In addition, I use a small screwdriver to tune the speed dial inside the motor to let it runs at 3000Hz with 3000Hz reference tape. The soldering is pretty ugly, but it works well over a year now and I think I did a great job to maintain this thing running. I then tuned the recording bias, Dolby reference level, and output balance. This thing now works like a charm.
Taking apart the machine is fairly easy. just unscrew four screws on the side and one on the back.
Inside it uses a Tanashin style mechanism. Belt is in fairly nice condition. The tape counter belt does melt into goo, but it doesn't affect usability.
Pretty ugly, but it works. I didn't know flux at that time.
Taking apart the machine is fairly easy. just unscrew four screws on the side and one on the back.
I decided to practice my soldering skills by soldering/desoldering the component from my cheap Aiwa PS120, which is fairly simple PCB board and can be perfect for practicing. It uses a single chip TA2069F for both motor driver control and power amplifier output. I learned how to apply flux on the soldering point for easier soldering/desoldering.
PCB layout diagram. It uses a single TA2069F for both motor driver control and power amplifier for audio.
The only picture I have right now. Very simple mech and actually very stable.
PCB layout diagram. It uses a single TA2069F for both motor driver control and power amplifier for audio.
I then started my first serious project: Refurbishing Toshiba KT-4252. I dissembled it and replaced capacitors, pinch rollers and two belts, along with Dolby level calibration and speed calibration. This took me over 4 hours, and it runs absolutely steady as a workhorse. Replacing capacitor is quite fun but time consuming, especially when some soldered pot will not come off.
PCB and Mechs.
Dissembling shell and frames from the mech.
Found a problem in the FF/REW engaging mech.
PCB and Mechs.