I have an Oberheim Matrix 1000 that had a pretty loud power supply hum issue. I hired a local electronics shop to install a new power supply as detailed here: https://www.gearslutz.com/board/electronic-music-instruments-and-electronic-music-production/1006972-oberheim-matrix-1000-psu-fix-guide.html#post11047551
New power supply is installed, working and nice and quiet. The power hum problem is gone.
Since getting the unit back with the new power supply none of the 800 ROM patches work or sound correctly. It is like they have become corrupted in some way. Some of them don’t make sound at all. Some do, but sound very odd. Some play out of tune.
I am able to load patches in the 200 RAM slots without a problem. These sounds all work perfectly. The unit plays like normal and sounds great if I am using any of the loaded 200 RAM slots.
I read a forum post online where someone was having a similar issue as I have described. Someone recommended updating the firmware chip thinking this might solve the issue. I did purchase a 1.16 firmware upgrade EPROM and installed. Unfortunately this did not change the issue/problem with the ROM patches. They still sound strange and corrupt.
Does anyone know where the 800 ROM patches are stored? If they were on the firmware EPROM I replaced I think the issue would have been solved.
I would like to get the ROM patches restored to normal if possible. Thanks in advance for your help.