Schematic needed for Quadraverb

  • Thread starter Thread starter jwalker262
  • Start date Start date
J

jwalker262

New member
Originally posted this in The Rack but no response, so I'll try over here...

I have an old Quadraverb Plus that's gone belly up. I'd like to see if I can repair it. I checked with Alesis about getting a schematic for it, and they want to charge $50. The unit itself isn't worth much more than that!

Any ideas where to look for a schematic so I can repair this guy? The problem is more than likely in the analog input stage, but without a schematic I'm going to have a hard time finding exactly where.

Thanks,
John
 
What is the problem you are having. I might be able to help.

Paul
 
Well, I traced it through and it looks like a short.

I pulled it apart and did some poking around with a voltmeter. The 5V regulator is getting really hot and there's no 5V coming out of it. I checked it with the meter and I've got about 40 ohms between 5V and GND. I thought the regulator might have smoked so I replaced it, no luck.

I'm thinking maybe I lost a capacitor and it's shorting?

John
 
Your problem does sound like one of the 0.1uf bypass caps that are on the +5v line of the IC's. These caps are usually blue in color. Look for one that looks a little burnt and that should solve your problem.

Paul
 
Thanks!

Thanks Paul - I thought that was probably where I should go next but without a schematic you're never sure which caps go where.

We'll try this and see if we can get it.

John
 
You must log in or register to reply here.
Back
Top