Ensoniq Mirage power supply issues

Any music gear discussions that don't fit into one of the other forums.

Moderators: Joe., lisa, luketeaford, Kent

Post Reply
Rynoise
Learning to Wiggle
Posts: 6
Joined: Mon Jan 27, 2014 6:43 pm

Ensoniq Mirage power supply issues

Post by Rynoise » Thu Jan 01, 2015 3:46 pm

Hey all,
awhile back posted some problems my mirage was having, and it was suggested that the cause was bad caps on the power supply board. (sorry for the long response, got busy with school). well, finally got around to pulling the unit apart, pulled out the board, and while none of the caps have any visible signs of damage, the board itself looks... weird. the underside of the board looks swollen in spots, and other regions have a raised, vein-like fractal pattern. i'm guessing it's not supposed to look like this? i included a picture for reference.

User avatar
ersatzplanet
Synthwerks Design
Posts: 6446
Joined: Fri Mar 06, 2009 1:18 pm
Location: Seattle WA

Post by ersatzplanet » Thu Jan 01, 2015 5:14 pm

I cannot see any attachments but "back in the day" if the board was flow soldered at a slow rate, the solder would sometimes flow under the solder mask along the traces and make bulges and wrinkles like you describe.

I have 3 mirage samplers, 2 racks and a keyboard. I have had problems with them in the past that manifest as erratic performance or failure to do some things. I have so far found that all of these problems were fixed by re-seating the socketed ICs. Older machines like this often suffer from "dissimilar metal effects" in which corrosion occurs where two different metals (the IC pins and the socket) are in long contact with each other. All you have to do is pry up one end of the IC, push it back down, pry up the other and push it back down. This will often wipe the contacts clean. One of my Mirages was a "broken" one that I bought cheap for parts (the CEM filters were worth over $20 each and there are 8 of them in there) and did this and it worked perfectly and has for years since.

Worth a try since you have opened it up already.
-James

James Husted - Synthwerks, LLC - www.synthwerks.com - info@synthwerks.com - james@synthwerks.com
Synthwerks is a proud member of the Mostly Modular Trade Association (http://www.mostlymodular.com).
Always looking to trade for Doepfer P6 cases

kinkujin
Common Wiggler
Posts: 187
Joined: Sun Mar 03, 2019 2:06 pm
Location: USA

Re: Ensoniq Mirage power supply issues

Post by kinkujin » Sun Mar 22, 2020 11:09 am

Hi - necropost - seems appropriate in this case ...
I was playing my newly fixed Mirage today. All was well, when display started flashing and then a couple of pixels lit up in the display, I heard the drive start to clunk away, then it just went dark.

I unplugged from the wall and replugged in and nothing.

So again I unplugged and now it is just sitting. Do these overheat (I have the gray metal one- DSK8 - mkII)?

If it’s a power supply problem, is this how it would go? Thanks for any help.

-kinkujin

Post Reply

Return to “General Gear”