Hello About to dive into a few machines since my last working one failed to play a tape. I have two plastic Sony WM AF 44(23,29) and AF 48 that have no screws to access the inside of the unit. how do you split or open the case without cracking it ? Tricks...tabs....magik juice ?
Others may chime in but these are commonly held together by tabs. I just did one of these and started by loosening it near the battèry compartment as I could clearly see a tab. I then used some little plastic levers I have for car interiors to slide alongbyhe edge until I found the next tab and so on. Always Google for a teardown pic or vid and look for a service manual to. Once you have done a few they are not difficult.
I have several models with these issues. Among those share the same tabs is a highly collectible model known as "Big Lebowski"' walkman. It is easier to open the 2 compartment by pulling the 2 compartments ( back and front panels) from the top part where the play, FF... buttons are (since this is the biggest gap separates these 2 compartments.) http://www.stereo2go.com/forums/threads/how-to-open-up-my-sony-walkmans.1029/#post-7981
I had good luck separating the sides with a sharp ,thin knife and then working the "claws" ( Sony's word -not mine ) loose from the two halves. It helps to shim the start of the opening and then work your way around the case. After some new belts one machine has some W/F issues and the other is a tad off speed. Another one was repaired and has a pretty decent sound -but it's pretty marginal in the fidelity department . I assume one out of the pile of 12 will be satisfactory . I notice that some have a speed adjustment . Still looking for information however
I personally have not met one without a speed adjustment pot. Some models, usually ones aimed at making voice recordings, have a speed control knob (or switch) on the outside, while others van only be adjusted using a screwdriver by opening up the unit or though a small hole. Some are labeled "speed adj." on the board, but even if isn't, the adjustment pot's usually there. They're also labled simply as "RV601" on Sonys.
Thanks for the tip! I'll look for a trim pot. I guess a schematic is essential and I have found a few on the web. The W/F issues with a small portable unit are just like reel machines ,but their causes would be fewer I suppose. I have noted that on some the capstan to idler contact is marginal and may be stiff on it's pivot. It seems like many of these machines never saw any maintenance and were in the throw away category.Unless you had the skills I couldn't many coming apart or even a service place taking one in for repair.
read the following link about how to open walkmans without screws https://www.petervis.com/walkmans/WM-BF22/WM-BF22 Opening.html
