Prophet 5 rev 2 problems

[scottcardin]

I have a P5 rev 2 that seems to have an issue with the CPU board. It started with the synth locking up—the memory display went blank, and the LEDs turned off—but the voices continued to fade. Restarting the synth brought it back to life. Here’s what I’ve done so far:

I checked the power supply, and the voltages are correct. I also removed the EPROM chips, cleaned the sockets, and reflowed the solder on both the sockets and the CPU board connector, as I know those can cause problems. I reinstalled the EPROMs, which have the 6.1c firmware.

Now, the synth powers up and produces the correct sounds, but the memory display is malfunctioning. It starts with patch 11 as expected, but when I select any other patch, the display either shows the wrong number or random lines.

I suspect that one of the EPROMs was failing, and my handling may have accelerated its decline. Any other ideas?

[gus]

I would go ahead and post this to the other hardware/software section of the Forum, as this section is specific to the Rev4.

Good luck!