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Yamaha Mt120 4-track is possessed

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Yamaha Mt120 4-track is possessed

Postby hithanksbye » Fri Apr 30, 2021 4:57 pm

I bought an old Yamaha Mt120 - the guy said it was in working order except tracks 2 and 4 were quieter on recording . That didn’t matter to me since only want to use it to digitize a bunch of old band tapes. I just received it yesterday and in my excitement I popped in a tape that is probably 20 years old. It worked decently for a few minutes (although it sounded pretty scratchy, I figured it was just the tape), but then when I popped in a different tape the thing started freaking out! It started playing at fast forward speed, then it would rewind and fast forward on its own, the play head going up and down on its own. Basically it seems possessed... I’m capable of taking things apart and replacing physical parts so I’m hoping it’s something mechanical. This 4-track has soft buttons so I’m hoping it’s not something like a processor or something that I can’t figure out. Any ideas? Also, if it’s something mechanical where do y’all pick up these old parts? Thanks in advance.
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Re: Yamaha Mt120 4-track is possessed

Postby James Perrett » Fri Apr 30, 2021 5:32 pm

My first thought is that the second tape was loose and it went the wrong side of the capstan when you loaded it. This can cause the tape to play fast.

My second thought is that all the switches are probably dirty and need a good clean. This includes the internal switches too. Hopefully, once you've given everything a good clean, you'll have a better idea of what is going on. You may also find that the belts are loose and need replacement if they haven't been changed since the machine was new.

I use Servisol Super 10 for switch cleaning and IPA for head cleaning.
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