Hello! I bought a small lot of faulty Walkmans and one of them is a Sony WM-EX404. I did the following maintanance: 1. Removed the perished belt and cleaned the pulleys as much as i could with IPA. 2. Replaced the belt with a good quality replacement specifically for this model. 3. Cleaned the pinch rollers and capstans with cotton swabs and IPA. 4. Set the speed pot using a good quality 3Khz test tape. The Walkman plays and sounds fine. FFW and Rewind work fine. This issue is the Auto Reverse. Hard to explain, but when I press the reverse <> button during playback it makes mechanical sounds for a while and then stops and beeps. Sometimes it pulls tape out of the cassette too when I do this. I tried with the door open and the lid switch pushed in to see. I can see the head mechanism engaging and disengaging. Some things to note... The system is full logic control. From inside with back panel removed there seems to be some switch that moves left and right when engaging the auto reverse.
