Notifications
Clear all
Topic starter
Hello, just tried to upgrade my working EX5R from the original eproms to the latest available versions but accidentally installed them backwards. (Unfortunately, Yamaha did not “idiot proof” the sockets by making it so the chips could only be installed the right way, and sure enough, this idiot did it wrong!) I powered the unit up, but just got a green screen on the display. When I realized my mistake, I removed the chips and reinstalled them the correct way, and for a moment, I thought all was well because it ran through the normal boot up with the “I am ready” screen…but then the unit just froze. I shut it off and turned it back on and only got a blank display. It lights up, but says nothing. Now the synth will not boot up at all. We even tried reinstalling the original chips but to no avail. I feel like I may have just made a thousand dollar blunder.
Can anyone help?
Posted : 24/02/2025 9:42 pm
Yamaha shouldn't "idiot proof" the electronic components on the PCBs that are not customer serviceable. Which is nearly everything. Surface mount, through hole, etc. They mostly all have markings to indicate pin 1 and these markings are sufficient for authorized service technicians to properly orient the parts according to pin 1 markings on the PCB silkscreen or pin 1 "markings" (indicators) on sockets if components happen to have sockets. Looking at the schematics (at least for the non-R version which I imagine is the same) the EEPROM uses sockets and these would be DIP package devices. So absolutely there's a pin 1 indication on the PCB, socket, and on the EEPROM itself.
You see the half circle in the middle of the top. This is the pin 1 indicator on the DIP package EEPROM part. You can see that flipping the part around connects A18 directly to VCC. A0 and A16 are shorted to GND. And lots of address pins are connected to data pins and vice versa.
Got to go - so I'm cutting my message short. More later.
Current Yamaha Synthesizers: Montage Classic 7, Motif XF6, S90XS, MO6, EX5R
Posted : 25/02/2025 8:36 pm
