4mo ago

Niche Cassette Player Question (Sony WM-EX631)

So I just recently got a Sony WM-EX631 Cassette Walkman from eBay. Its been pretty good the first month, had to replace the cassette door on the transparent case but other than that fine. Now, it seems there is an issue with the autostop/autoreverse function. The cassette was intermittently reversing to the opposite side at random, like in the middle of a song. Once I changed the mode to not reverse, now it just stops as soon as I hit play even mid tape. I'm wondering if the mechanism for detecting auto reversing needs attention. From what I've gathered they use some sort of transducers on a reflective gear to accomplish this. Is that information correct? If anyone knows anything I'd appreciate it.

24 comments

The mechanism for detecting autoreverse needs attention.
Usually there's a tension spindle that detects if the tape has ended, becauaw the pulling lug pulls and theres no more tape to feed.
Maybe the spring lost tension?
You need more info, probably an expert, but you can retension it by removing it and twisting it while heating in a fire (doesn't work great but might be enough).
- I'll check that out. The unit is in very good condition otherwise and I have the service manual. I probably will have to attempt to locate an expert. I've taken it apart since I got home and couldn't identify the problem.
  
  Sorry, also one of the capstans or rollers could be sticking, increasing the resistance which also signals that the tape has reached its end.
  Interesting way to confirm: Does it autoreverse both ways equally? If so it is more likely to be the spring, if not then one of the capstans or rollers or the reversed lug is sticky.
- I bet this is it
It sounds like It may be a chewed up tape. Is this happening with every tape or just one?
- Unfortunately its all of them. I can get it to fast forward and rewind. It just won't play, and if its in autoreverse mode it constantly switches sides.
  
  That's mad weird.... Beyond me there bud I'm sorry.
Try a different tape. Maybe your tape is getting stuck.
- Its all of them :\ even my test ones.
  
  Ok one of the capstans is likely to be on a pivot, to detect tape tension for auto reverse. See if it is sticky etc. Try web search for this problem?
I don’t know your specific machine and haven’t used cassettes for years, but from experience back in the day the first thing that occurs to me is uneven tension - what happens if you manually fast forward the tape to the end then rewind it? Does retensioning the tape help at all?
- That was the first thing I did :\ unfortunately it does this to all tapes I put in it. I opened a fresh cassette I just got yesterday to test it and the issue persists. As a slight update, I contacted the seller. I feel bad as they are sending me a new unit. I do not think this was their fault in any way. But I appreciate it nonetheless. Another user suggested heat treating the springs, that will be my next go-to. Thank you for your help though, I really do appreciate it.

24 comments