Oberheim OB8 - Keeps Restarting

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Svanis
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Oberheim OB8 - Keeps Restarting

Post by Svanis » Tue Jun 13, 2017 2:44 pm

My OB-8 keeps resetting itself if I play too many notes. It happens very regularly, which makes me nervous about playing it until the problem is fixed. What's the issue? Dying battery, power supply? I live in Europe so it's on 240v.
What's odd is that I was tweaking Bank A preset 1 once when it happened, and for some reason it wrote it to memory, even though I did not use the write option. Memory protect was off, though.

It also has a dud key, could that be the source of the problem?

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desmond
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Re: Oberheim OB8 - Keeps Restarting

Post by desmond » Tue Jun 13, 2017 10:24 pm

If there's weird things going on, it's probably time to send it in for a service - could be any number of issues (I've been watching a few SynthChaser vis on YouTube lately, he's overhauled a few OB's. There are some notorious failure points on the OB's...

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Re: Oberheim OB8 - Keeps Restarting

Post by sam » Wed Jun 14, 2017 7:05 pm

I won't be a dodgy key .....

It's a really good idea to recap the power supply on a oberheim these days.

Nevertheless something is interrupting the logic and because I do service these things it could be anything.

Probably start with cleaning all the connectors inside.
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Re: Oberheim OB8 - Keeps Restarting

Post by Svanis » Sat Jun 17, 2017 1:27 am

Yes, I imagine the power supply is the problem, I bought it from the US (I live in Europe) and the seller said he had no issues like this previously, no reason to think he was lying. It happens if it's left on for too long, I ordered replacement capacitors and bridge rectifier and will be installing these as soon as I get them with the help of a friend. I'm thinking it could be the extra stress as a result from the switch from 110V to ~220V. Correct me if I'm thinking out my arse here. :idea:

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Re: Oberheim OB8 - Keeps Restarting

Post by madtheory » Sat Jun 17, 2017 5:25 pm

Yes you are taking a big risk here. Changing from 110 to 220 is not normally going to cause a problem like this. Something has probably gone amiss during shipping. Best send it to a tech for a service. A tech who knows Oberheims! You could damage other parts in the synth, parts that are expensive to replace.

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Re: Oberheim OB8 - Keeps Restarting

Post by Svanis » Thu Jul 13, 2017 10:05 pm

Actually it was a very simple fix. I replaced the capacitors and other parts in the power supply a while ago using that repair kit and it runs like a dream since then. The problem was that the old parts had gone bad after so many years they malfunctioned when the synth warmed up.

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Re: Oberheim OB8 - Keeps Restarting

Post by madtheory » Fri Jul 14, 2017 10:55 am

That's good news. You're lucky! Enjoy this wonderful instrument :)

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