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

[dmitri]

Sorry, I just realized you wanted me to check voltage.
pin 6 through 9 =4.65
pin 10 = 4.85
pin 12 = .01
pin 13 = .03
14 = 4.85
16 =4.75
18 through 20 =4.75
21 = 2.73
24 = .01
27 = .04
28 = 2.38
29 = 2.38
30 = 4.83
32 = 2.4
33 = .02

It all looks right except pin 27. If the MIDI LED is connected you should be reading around 3.6V there. If the LED is not connected then it should be close to 0.

At this stage I can only suspect the following.
1. When you insert Atmega into the socket, you don't insert it all the way in.
2. A faulty crystal or bad soldering of the crystal/C1/C2/pin12/pin13.
3. Atmega failed.

[jeffbeckib]

ok I didn't have the led connected. with the led connected pin 27 is measuring 2.5, and now for some reason it's 0.00 when i disconnect it.

[dmitri]

ok I didn't have the led connected. with the led connected pin 27 is measuring 2.5, and now for some reason it's 0.00 when i disconnect it.

It can be 2.5V.

[jeffbeckib]

At this stage I can only suspect the following.
1. When you insert Atmega into the socket, you don't insert it all the way in.
2. A faulty crystal or bad soldering of the crystal/C1/C2/pin12/pin13.
Im assuming your talking about pin 12 & 13 on the atmega socket. Is there polarity on the crystal? If I do a continuity test from the 16mhz crystal to pins 12 & 13 on the atmega socket I get a beep. Does it matter which of the 2 pins from the crystal go to 12, and which goes to 13?1 pin on he crystal beeps on pin 12, and the other pin on the crystal beeps at pin 13
3. Atmega failed.[/quote]

[dmitri]

Crystals don't have polarity.

[jeffbeckib]

Crystals don't have polarity.

ok, so is there anything else I can test? Is there a way to test the crystal?
I know I have the atmega all the way in,

[dmitri]

Crystals don't have polarity.

ok, so is there anything else I can test? Is there a way to test the crystal?
I know I have the atmega all the way in,

You can temporarily borrow a crystal from PIC18F.

[jeffbeckib]

Crystals don't have polarity.

ok, so is there anything else I can test? Is there a way to test the crystal?
I know I have the atmega all the way in,

You can temporarily borrow a crystal from PIC18F.

you mean unsolder the 12mhz and solder it in 16's location? Can I make use of the 20mhz you sent also?
So there's no way to test the crystal with the meter like you do with a resistor?

[dmitri]

you mean unsolder the 12mhz and solder it in 16's location? Can I make use of the 20mhz you sent also?

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

So there's no way to test the crystal with the meter like you do with a resistor?

No.

[jeffbeckib]

you mean unsolder the 12mhz and solder it in 16's location? Can I make use of the 20mhz you sent also?

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

So there's no way to test the crystal with the meter like you do with a resistor?

No.

instaled 20mhz crystal in the 16mhz/20mhz slot, and still nothing