atmega64 based device (RW minicommand) No bootloader appearing. Can it be fixed?

Hi all,

Apologies if this is the wrong place to post, If so it would be good to know where I can get some advice. I have searched a lot for a solution to my problem and haven’t found much. I will describe my issue as simply as possible.

I own a minicommand which is an atmega 64 based midi controller and processor. Having not used it for a while I connected the incorrect psu AC9v by mistake :blush: . When I switch it on now it doesn’t load to either program or bootloader as before but instead lights both led’s and shows a full lcd display. If I hold buttons and turn on (previously this accessed different modes) It does the same but without the backlight. I have tried to connect to the device through both pieces of software I have on my laptop (a patch loader and a sketch compiler/loader), neither can make a connection through the midi ports.

I have some questions and would be very grateful if someone could help:

Is it possible to connect via usb to serial (midi ports) and diagnose or reprogram this device?

Has the boot loader simply been erased or is it something possibly more serious/totally different?

Thanks, does anyone have any ideas?

So you connected 9 VAC to something that's supposed to be connected to what? If that's going straight into the Vcc of the chip (ie, it was supposed to be 5v DC), you've likely destroyed the chip and probably most other semiconductors on the board.

Those symtoms are consistent with IC damage - pins in a severely abused IC will often short to ground (or less often vcc) - which would light the LEDs if they were wired active low (which is more common).

Ah ok. Thanks drazzy. That's good to know. Maybe it's time to salvage the case and controls to build a new device.