Looks like your DX7 "logic" side is working, in other words, you have the +5V line functioning out of the PSU and the DX7 main CPU etc is working.
However, I would begin to look for the problem from the PSU +15 and -15 DC lines. Please see a part of the schematic attached to this message. First check those two fuses F3 and F4 (remove them from the board, just to make sure, and check for continuity on your multimeter) after that you can measure the DC voltages coming out of the PSU from the connector when the DX7 is powered on. As always, be careful inside a synth when it's powered on! You can check the pinout from the picture below. If all the DC voltages are correct, it gets a bit more complicated, I'm sure someone here is more knowledgeable than me.
DX7 schematics can be found in many places, for example here: http://yates.ca/dx7/Schematics%20&%20PC ... 0Tiled.pdf
However, I would begin to look for the problem from the PSU +15 and -15 DC lines. Please see a part of the schematic attached to this message. First check those two fuses F3 and F4 (remove them from the board, just to make sure, and check for continuity on your multimeter) after that you can measure the DC voltages coming out of the PSU from the connector when the DX7 is powered on. As always, be careful inside a synth when it's powered on! You can check the pinout from the picture below. If all the DC voltages are correct, it gets a bit more complicated, I'm sure someone here is more knowledgeable than me.
DX7 schematics can be found in many places, for example here: http://yates.ca/dx7/Schematics%20&%20PC ... 0Tiled.pdf
Statistics: Posted by ttcaven — Sun Apr 07, 2024 8:52 pm