how can I know if my mac is truly communicating with the MD?

[dmitri]

Switch back to 16MHz.
Your Atmega either has failed or somehow lost all it's firmware, including bootloader (provided all your resistance and voltage readings were correct).
If it just lost all firmware, reprogram it using an ISP cable. See http://www.megadrum.info/content/progra ... bootloader for details.

[dmitri]

As a last test before re-programming Atmega, take all 74HC4851 ICs out of their sockets and see if it makes any difference.

[jeffbeckib]

First, I didn't send you anything. And yes, you can try 20MHz crystal.

Wait, you don't work fort synthex? How come the synthex people aren't trying to help me?

[dmitri]

First, I didn't send you anything. And yes, you can try 20MHz crystal.

Wait, you don't work fort synthex? How come the synthex people aren't trying to help me?

LOL.
Read this again: viewtopic.php?f=3&t=502

[jeffbeckib]

So the only way to reprogram it is using a parallel connection to a PC? I'm on a mac, no lpt port... No way to do it using usb?

Switch back to 16MHz.
Your Atmega either has failed or somehow lost all it's firmware, including bootloader (provided all your resistance and voltage readings were correct).
If it just lost all firmware, reprogram it using an ISP cable. See http://www.megadrum.info/content/progra ... bootloader for details.

[dmitri]

So the only way to reprogram it is using a parallel connection to a PC? I'm on a mac, no lpt port... No way to do it using usb?

A PC, PonyProg, LPT port, a few wires and resistors IS the easiest way to program a blank Atmega IC. All other methods require building/buying a proper programmer.

[jeffbeckib]

So the only way to reprogram it is using a parallel connection to a PC? I'm on a mac, no lpt port... No way to do it using usb?

A PC, PonyProg, LPT port, a few wires and resistors IS the easiest way to program a blank Atmega IC. All other methods require building/buying a proper programmer.

ok

[jeffbeckib]

The pin on your photo is pin 31.

I've been doing some extensive testing with dmitri. Is there anything else you can think of based on all the testing I've done? All readings of voltage and resistance has checked out ok, but I'm still getting a blank LCD with the backlight being ON. Even if I disconnect the LCD and power up holding the left button for a few seconds, then pressing the down key to get it into firmware mode for me to upload it again, I can tell it's not going into that mode because the midi led used to light up solid when it went into that mode.

[Synthex]

How come the synthex people aren't trying to help me?

Sorry, but I've already sent more than 40 private messages to solve your problems ...

[Synthex]

The pin on your photo is pin 31.

I've been doing some extensive testing with dmitri. Is there anything else you can think of based on all the testing I've done? All readings of voltage and resistance has checked out ok, but I'm still getting a blank LCD with the backlight being ON. Even if I disconnect the LCD and power up holding the left button for a few seconds, then pressing the down key to get it into firmware mode for me to upload it again, I can tell it's not going into that mode because the midi led used to light up solid when it went into that mode.

Components may be toasted ...
The PCB may be damaged ...