Thursday, April 27, 2017
Oberheim Matrix-12 Synthesizer Power Supply Issues RESOLVED
In this video I show what I did to resolve my power supply issues on the Oberheim Matrix-12 analog synthesizer. Symptoms were intermittent non-boot, locking up, and the dreaded Voice 1 Processor Malfunction message. Along the way I'll talk about how the power supply works and how it is different than many synths from the era prior to this. Even though the Oberheim Xpander is a little different than the Matrix-12, its power supply works exactly the same. This may not enable you to fix your Matrix-12/Xpander completely, nor answer ALL questions you may have...but hopefully it will be helpful information.
YOU ASSUME ALL RISK WHEN REPAIRING YOUR OWN ELECTRONIC INSTRUMENTS! There's no shame in asking a friend for help or taking it to a reputable synthesizer technician. BE SURE TO UNPLUG THE SYNTH PRIOR TO DOING THIS KIND OF WORK.
1:10 Getting Started
1:54 Dealing with an SMPS
3:16 Why did Oberheim use an SMPS?
3:40 Why I'm NOT going to troubleshoot this power supply
4:38 Power Supply Restoration and Results
Here are the Mouser parts numbers:
Power Entry Module - 871-B84771A0001A000
2W Shunt Resistors 0.1ohm - 667-ERX-2SZGR10V
sorry I don't have capacitor numbers, I did that work 2 years ago