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.
Ensoniq Mirage power supply issues
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ersatzplanet
- Synthwerks Design
- Posts: 6903
- Joined: Fri Mar 06, 2009 1:18 pm
- Location: Seattle WA
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.
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
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
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kinkujin
- Wiggling with Experience
- Posts: 389
- Joined: Sun Mar 03, 2019 2:06 pm
- Location: on the shores of Lake Ontario
Re: Ensoniq Mirage power supply issues
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
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