Akai AX80 service manual, schematic or service diagnostics

[fzv]

hi all

can anyone (pretty please) help me with a scan of the Akai AX80 service manual, schematic - or does anyone know what buttons to press to get into the diagnostic mode ?

i suspect a dead cem 3372 vcf/vca chip, but have no way of telling which one.

thanks,

fzv

[plus321]

You can find a lot of service documents in this thread.

http://analogue-heaven.1065350.n5.nabbl ... 94998.html

Had it bookmarked from when I was calibrating one.

[fzv]

cheers ! the dropbox links there seem to have expired, but I've PM'd the thread author...

[Swayze]

If one of your voices is dead/distorted on your AX80, all you need to do is power it up, press and hold 8 keys and count. The voices will trigger 1-8 left to right. When you determine what voice is faulty, use a chip puller to remove that 3372 chip.

Synthparts here at VSE might have more of these in stock. I got a replacement 3372 chip from him a while back and my AX80 works fine now.

[synthparts]

Yes I still have some CEM3372s in stock. When replacing them in the AX80 you should replace them with the same rev chip (usually "B" or "C")...

[tim_m]

While perusing the internets today, I ran into the service manual on archive.org here. This scan is a bit more complete (and in color) than the other copy I have. Happy fixing!

[paul.boos]

Greetings,

I posted a Q here: https://www.gearslutz.com/board/geekslu ... an-do.html and after continued googling I would up here. After reading through this forum post and responses I'm pretty certain I can do the chip replacement myself, but I have a follow-up Q that I hope someone can answer given what I have read in the service manual thus far...

In it it talks about an adjustment procedure for getting the levels of the waves correct. Not being an electronics technician it seems this is something that may need to occur after chip replacement of a 3372 chip. Is that what people have experienced? Or is the drop in replacement generally been all that is necessary? What adjustments have people needed to make following a chip replacement.

I believe I have identified the bad voice as #5. I can work around it for an upcoming gig, so I am trying to assess whether to try and fix it before or after the gig (it's my 30th college reunion and we're putting our talent show band back together...)

[synthparts]

You can usually just plug in the new 3372 without re-adjusting. As I stated above you need to get one of the same rev. I still have a rev B 3372 in stock.

[paul.boos]

Thanks, I'll open up my keyboard this eve and see what rev I have...