Martin Mac 301 fault

[macarts]

Hi Folks,

Had an odd fault on two of my Mac 301's (odd because it happened to two adjacent fixture in the rig at the same time) The fixtures reset fine and they output light for a few minutes then they stop out putting light.(they still pan and tilt) I initially thought it was a data issue so I changed the DMX cables (and the power cables). I readdressed them and swapped them with other fixtures in the rig and the fault remained. There are no errors logged and none of the temperature limits have been reached that would cause an LED shut down.

I have restored the factory defaults which made no difference.

Any suggestions?

Chris

[indyld]

You are right to wonder about heat in faults when things work for a while, then stop working. If you have completely ruled out both data/control issues, finger trouble, and that the units are not dowsing due to temperature control issues (real or imagined), then the final port of call for me is capacitors that act OK for a bit and then give up when warm. In this case, those in the power supply to the LED drivers.

 

Given that you can still control the fixtures and that the processing all still works, this problem is in a relatively small area. But first I'd look for any reason for the fixture to dowse (and apparently not report it)first, including temperature monitoring components and wiring. Given that the fixture apparently thinks everything is OK, I'd have a good poke around in what is actually making the LEDs light and wonder if the fixture is 'thinking' it's lighting them but it isn't actually happening at the end of the control chain.

 

Start with big changes like swapping a known good whole driver board or the PSU, and then narrow stuff down if need be.

 

On a topical note, I had an ART2000 dimmer yesterday that was playing up after getting totally cooked by ambient temperature on a well-known West Country dairy farm at the weekend. Overcooked capacitors are in the suspicion mix at the moment.

Edited July 3, 2019 by indyld

[macarts]

That's great Rob. That's given me a first point of investigation. I'm off on holiday from tonight but I will be on it as soon as I get back.

Thanks

Chris

[rheadproductions]

On 7/2/2019 at 11:45 PM, macarts said:

Hi Folks,

Had an odd fault on two of my Mac 301's (odd because it happened to two adjacent fixture in the rig at the same time) The fixtures reset fine and they output light for a few minutes then they stop out putting light.(they still pan and tilt) I initially thought it was a data issue so I changed the DMX cables (and the power cables). I readdressed them and swapped them with other fixtures in the rig and the fault remained. There are no errors logged and none of the temperature limits have been reached that would cause an LED shut down.

I have restored the factory defaults which made no difference.

Any suggestions?

Chris

Hi Chris,

I don't suppose you found out what the issue was?

we've got 8 of these fixtures and 2 have now developed the same fault while been used over Christmas!

kind regards,

Matt.

[Richard CSL]

check the cooling fan is working. if the head overheats the sensor shuts the RGB dimmers off.

[electronicsuk]

From what I can recall the entire fixture runs on a single 48V PSU, so if pan/tilt are working fine then it's probably not worth spending much time on the PSU. The LED driver board on the back of the head is pretty easy to get to, just four screws to remove. From there it should be pretty easy to ID the power to the driver board from the cable size (I believe the cores are orange), so check that you've got 48V there to rule out any cable breaks.

Like most heads, there are lots of connectors on the boards so probably worth re-seating the ones that are easy to get to and see if this helps. As already stated, check that the fan that cools the LEDs is working and clean. The plastics are also pretty hopeless on these heads, so make sure you haven't got any screws floating about inside the units that could be causing problems. 

If you go into the service menu then you should be able to get the fixture to "lamp on" without any DMX connected, which would rule out a control issue, however unlikely.

Edited January 2, 2022 by electronicsuk

[michaelnguyen]

I've had the similar problems on all 4 of mine. 
This mod fixed it.
https://www.martin.com/en/site_elements/guide-reset-modify-of-mac-301

[Dr D]

I am an engineering technician that has work on many robotic devices in my career.  A friend of mine has 16 of these MAC301's that suffered from the premature reset problem.  I proceeded to modify all 16 units.  In the process I found one that has a burned up motor driver PCB and several others that of overheated boards and some with bulging filter caps.  A spare unit also existed so I proceeded to reverse engineer the entire workings of this thing. 

I found that the main power supply is set to 56 volts, but the marking for this power supply indicate it is a 48 volt power supply.  The caps on the driver board are only rated for 63 volts and the clamping diodes are only rated for 60 volts!   The clamping diodes appear to be what fails on this PCB's and some caps are bludging. 

I suspect these power supplies are missadjusted and causes the driver to overheat and fail.   Any thoughts?  I have no service data.