Quadrasynth's display lit but blank; all else dead

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jerry aldini
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Quadrasynth's display lit but blank; all else dead

Post by jerry aldini » Wed May 02, 2007 8:39 pm

I have an original Alesis QSynth + Piano, circa 1995-6. Has always worked fine. I power it up the other day and the display is lit, but no characters. No sound, no kind of response from anything. I opened it up, no obvious loose connections, burnt boards or anything.

Any suggestions as to what might be the problem? Thanks.

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Post by Maschinengeist » Thu May 03, 2007 3:01 am

Have you checked the fuses? First step.
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Post by Stab Frenzy » Thu May 03, 2007 3:20 am

Does the Quadrasynth use a wall-wart power supply? A lot of the Alesis stuff uses AC supplies and if you give it DC you get the symptoms you've described. I'd check that first, if it does use an external supply...

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Post by jerry aldini » Thu May 03, 2007 3:37 am

I replaced the one fuse I saw when I pulled it apart, but there may be others (maybe on the other side of one of the boards. Guess I need to pull them to see the other sides.

Yes, it does use a wall wart, I'll switch it out with a different one in case this one's gone bad.

Thanks for the replies, I'll let you know what I find out.

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Post by Maschinengeist » Thu May 03, 2007 3:41 am

If I'm not mistaken, QSynth also use chip fuses. Labeled as FU (usually). They test like normal glass fuses.

There shouldn't be not fuses on the "other side of the board". All the fuses are on the printed side, not on the trace side.

The ac adaptor is a possibility... but I've got my reservations. But Stab might be right.
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Post by jerry aldini » Thu May 03, 2007 4:56 am

Thanks for the info, Maschinengeist. Would they be soldered in?

Does the Qsynth have any kind of internal battery? I saw a battery for later Alesis synths on eBay and it got me thinking that IF it had a battery, it could certainly be gone after 12 years. And if it died, it simply would have lost everything, meaning I'd have to replace the battery and then replace the "software"?

Again, I didn't see anything that looked like this battery inside my Qsynth, but that was before I knew what little I know now.

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Post by Stab Frenzy » Thu May 03, 2007 5:40 am

jerry aldini wrote:Yes, it does use a wall wart, I'll switch it out with a different one in case this one's gone bad.

Thanks for the replies, I'll let you know what I find out.
Make sure you use one the same as the original, most Alesis stuff I've used have 9VAC power supplies.

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Post by jerry aldini » Thu May 03, 2007 2:24 pm

Thanks Stab. However when I actually crawled under and looked, I realized it actually doesn't use a wall wart. I have some other Alesis rack stuff that does, so seeing those Alesis warts plugged into the power strip threw me. Oh well, eliminates that possibility at least.

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Post by Stab Frenzy » Thu May 03, 2007 3:05 pm

Bogus. Good luck sorting the problem out anyway!

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Post by Gothboy » Sat May 05, 2007 1:06 pm

I have an Alesis QS-6 which was the next step from the Quadrasynth. It uses a "lump in the line" power supply, not a wall wart. I don't know about the inside as I've never opened it up. Sounds to me like the internal battery is dead. :wink:

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Post by MrHope » Sat May 05, 2007 1:36 pm

This probably wont help, but try the factory reset. At least on the newer QS,'s it's hold down 0 and 3 during powerup.

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Post by jerry aldini » Thu May 10, 2007 5:24 pm

Thanks, MrHope. I tried the reset during powerup, but got nothing. I've been reading up on some stuff and I found schematics online. I'll open her up again this weekend, so maybe I'll have some more intelligent observations and questions next week.

I'm also saving some cardboard, thinking I might have to box her up and send her up to you in Canada, Maschinegeist.

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