Martin Mac 500 Not Changing DMX Address

[bsidebob01]

I have 4 Mac 500's, all of them have developed a DMX fault (apparently simultaneously) whereby their DMX address stays at 1, they were orginally in sequence from 400.

 

When I go into the dadr menu to change the address I can see that 400 (or whatever number in the sequence the fixture is) is already selected, and when I press enter to store that address it just goes back to 1 and does not receive DMX from the desk as it is the wrong address.

 

I have reset the fixtures, powered them down and back up again, but the problem persists. Interestingly the red DMX light does not glow when connected to the desk, but the desk works as it can control other fixtures fine.

 

Is this possibly a CPU / Motherboard issue or something else? It just seems strange that all the lights developed exactly the same fault at once.

 

Thanks for any help.

[gyro_gearloose]

As with most of the earlier Martin products, your Macs can be controlled either by DMX or Martins own protocol. Its possible that your Macs have somehow been set to respond to the Martin protocol rather than DMX. Have a look at PSET to see which mode your Macs have been set to.

 

From the Mac manual:

1. Apply power to the MAC 500/E.

2. If you want to change settings while the MAC 500/E is in a flight case, push [MENU] and

[ENTER] simultaneously to disable pan and tilt reset. The partial reset procedure can take 2 - 3

minutes and will result in error messages being displayed; this is not a fault with the fixture.

3. Press the [MENU] key and then press [up­] or [Down] until the display shows PSET. Press [ENTER].

4. Press [­Up] or [Down] until the desired protocol (Martin, or DMX mode 1, 2, 3, or 4) appears on the display.

Press [ENTER] to confirm.

5. Press [­Up] or [Down] until the display shows dAdr (to set a DMX address) or MAdr (to set a Martin

address). Press [ENTER] to confirm.

6. Press [­Up] or [Down] to select the address. Press [ENTER] to confirm.

7. Press [MENU] to return to the main menu. The address is displayed.

[KevinE]

This rings a bell, I've had the fault before and I think it was caused by a stuck chip select line which wouldn't allow writing to the serial eeprom. Without glancing at the diagram I can't be more specific.

No idea why you'd have it on 4 of them though :blink: