[SOLVED] Sony WM-EX508, wont behave normally after belt replacement

Discussion in 'Tech talk' started by Kawawete, Jul 30, 2022.

  1. Kawawete

    Kawawete New Member

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    Hello,

    A few days ago, I bought myself a WM-EX508 with what I thought was just a belt issue on it... Boy was I wrong !

    After fitting a new belt (same size/thickness as the original) when I press play, the mechanism seems to auto reverse indefinitely. I made a little video so you can see (and hear) what's happening.



    Thanks in advance for any suggestion, advice :)
     
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  2. Kawawete

    Kawawete New Member

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    Re,

    So after a LOT of pondering, I took the "the electronics are whack" route. And I was right ! The IC701 chip (the system controller) had soldering issues, some joints cracked. I didn't notice it until I randomly pressed on the chip : the mechanism stopped doing weird things and started to play my tape :D
    I tacked every pins (with solder flux added) and the EX508 is alive again !

    I hope that can help somebody as in those old devices, cracked joints invisible to the eye might fudge a lot of stuff up.

    Anyway, I'm off, I'll be listening to all my old D'n'B tapes ;)
     
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  3. TooCooL4

    TooCooL4 Well-Known Member

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    Well done :thumbsup2:
     
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  4. Dfcruiser

    Dfcruiser Active Member

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    Great fix!
    Did you happen to take before/after photos? so we can see what "bad" looked like, and what "fixed" looks like?
    I have other walkmans that do this strange behavior I will look more closely, i presume solders are "good"!
    thanks for sharing!
    mike in SC
     
  5. Kawawete

    Kawawete New Member

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    Well, the solder cracks in my case were absolutely invisible, I just pressed randomly on the legs of the chips in search for bad contacts ^^
    On another note : I have to replace the pinchrollers as they both have an indentation where the capstan was and it causes a lot of wow/flutter, definetly some work left on this bad boy.
    I bought some others on ebay recently, I'll see if any of them exhibit the same issues.
     
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  6. Dfcruiser

    Dfcruiser Active Member

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    I'll check for something like that! I'm familiar with this unit, I have EX-502, and there is a thread on
    www(dot)tapeheads(dot)net/threads/sony-wm-ex508-any-thoughts-opinions-about-it.41384/page-2
    and I've got an EX-808 that is doing something that sounds similar! just keeps "reversing"! great find!

    I have not tried ebay rubber rollers, I haven't had good luck with belts I've gotten from ebay (too big), so I have been buying from Marian at "FixYourAudio.com", they arrive from Slovakia to SC/US in about a week, and quality seems very good (his tutorials on website are good too!)
     
  7. Kawawete

    Kawawete New Member

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    It's a great website ! I don't know if the EX510 pinchrollers are compatible with the EX502-508 tho
     
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  8. Dfcruiser

    Dfcruiser Active Member

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    I always let Marian at the website determine what fits what, just email him... there is a lot of compatibility within Sony, Panasonic, etc, e.g. when i need a belt for a Panasonic NX-60v or a RQ-SW-88v, neither listed on his site, he will find correct size and send. I've learned changing those rubber rollers usually makes a huge improvement!
     
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