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Author Topic: [troubleshooting] Otari mx 5050 mk III - 8  (Read 178 times)

Offline joebass

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[troubleshooting] Otari mx 5050 mk III - 8
« on: March 16, 2017, 10:03:52 am »
Hi Tape people!

First post from me - love that this forum is here!

I have been rewiring my studio and decided to pull my 1/2" 8 track otari out of storage and wire it up into my new patchbay for an all analog option for my clients.  The deck was working well, when I put it into storage about 3 years ago.  This time when I fired it up, the take up reel came on immediately when I powered it up and ran on it's own for about 5-10 minutes.  It ran regardless of the position of the tape sensor arm position and did not respond to any other transport control commands. I have a memory of it doing this years ago, but only for say 30 seconds, after which it returned to normal operation.  I'm guessing this indicates (increasingly???) leaky caps.  Now the unit is quiet, but the transport controls are completely dead.  I have checked the 3 fuses on the main circuit board, as well as exercising/deoxit for all of the reelsize/speed/pitch/cue controls. I have also unplugged and replugged all of the cable connectors I can get to in the belly of the beast.  The transport remains completely inoperative.  The edit light does not engage.  The capstan activates normally when the tape sensor arm is moved into place, and all of the speed/reel size switches audible active switches/relays somewhere inside the machine and change the capstan speed as in normal operation.  I have 2 two track 5050 machines that are working great.  Any help is greatly appreciated as I ordered a new used headstack that I only have a few days to audition, so I'd really love to get this thing rolling ASAP. 


Offline ironbut

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Re: [troubleshooting] Otari mx 5050 mk III - 8
« Reply #1 on: March 17, 2017, 12:38:33 pm »
Hi Joe,

You might find some troubleshooting help in the Reel to Reel Links sticky located above the General Forum. Lots of Otari stuff there.
In the days when that sticky was created, YouTube hadn't quite become the juggernaut it is today so I would also suggest doing a crawl through the pages of Otari 5050 related videos there.
I wouldn't be so quick to assume that leaky caps are the problem (although they very well could be). I suggest checking all the multi pin connectors on the boards (pull each one, clean the male end and reconnect).
steve koto
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