Automated Fixtures Troubleshooting and repair

[030366]

I looked around for a topic like this, but didn't find exactly what I wanted.

I've done minor repairs on moving lights with good success, but it's always been a situation when I've clearly seen the light doing something wrong, and tackled that thing directly--for example, the color wheel acting goofy, or lamp issues.

Now I'm the new ME, and I've been handed two MAC 600s that I've never seen before that need repair. One is "dead", and the other one "does whatever it wants to do".

Does anyone have any suggestions for a linear troubleshooting pattern that could be followed for an intelligent when one knows that there is a problem, but has no idea what it might be?

 

[chawalang]

So for the dead one this is pretty simple as far as looking to diagnose the power issue. First make sure your getting the right amount of VAC into the fixture. So use your multi meter and make sure its connected to a power source that has the right voltage. Now if thats all good you will need to meter from there to every possible point where signal flow could break. Now if i remember correctly this should be similar to a 2000 series fixture. The AC in will go to a small board that is on the same plate as the ballast, i forgot the name of this board but basically its a fail safe incase you get some crappy power coming into the fixture. In the event you do get this the board will fry breaking signal flow so other parts of the fixture don't get damaged. From there the flow has a break out to the fuses that are located above the 3 and 5 pin connectors and another break out that goes to the power supply. From the power supply you then have it going to the main pcb/logic board. I would meter to see if you have a break any where in signal flow from your pig tail to the actual PCB/logic board to see if something has gone bad. An easy way to see if the logic board is bad is once you can visually see the whole board, move the fixture pan back in forth in a decently fast motion, you should see some led's light of on the board if its still good. Moving the fixture like that will generate current to the board just don't go doing all day as it can damage the board.If your signal flow is all good meter the fuses for continuity to see if they have gone bad. I believe there should be those two fuses as i stated before above the connectors, two in the power supply and i think one or two on the PCB. If every thing is still all good from there I would unplug every attribute from your PCB one by one and try turning on the fixture after you have unplugged each one. Do this to see if there is a short in a harness of possibly in a motor or something. For the one that "does whatever it wants" could you be more specific so I would know where to begin?

 

[JD]

Diagnostics is 90% of the battle. When I did service, I was level 3, which means I got the unit after two other techs gave up. As a result, I never had anything that was easy! There is a simple procedure used in service that would be a good place to start. It is called "divide and conquer."

Basically, you have two of the same units units with different problems. That is fortunate! Start by exchanging sub-sections to see what is leaving unit A dead. Once that is identified, replace it and then start the process of swapping and see which swap causes the "does whatever it wants to" to change units. Now you have identified both failed parts!

 

[030366]

Good call, JD. I actually have several working fixtures as well.

Yeah, I'm just kind of in the dark here. I haven't even seen this "dead" fixture, and I don't know if "dead" means "no power", "not moving", "not striking", or "it fell from the electric and shattered on the deck". The other fixture...well, I can't consistently reproduce the behaviour, but I think that the divide and conquer method will work well.

Thanks, guys!

 

[chawalang]

Im also curious what venue this is in Florida, i lived/ worked in Orlando for two years and Miami for a year.

 

[jhochb]

Good Morning 030366

Chawalang has some good pointers. The 600 /500 are older & are setup a little differantly.
Power comes in thru a fuse & to the transformer, line voltage then goes to the lamp circuit.
If its a lamp issue check the thermal switch.
Low voltage comes off the secondary of the transformer ( 3 pairs ) to the PCB. check all the fuses ( fixture unpluged )
If the LED display lite up but all the segments are lit, than the fixture is tapped to the wrong voltage.
do NOT plug or unplug the motors with the power ON! The motors always have power to them. you can blow a driver chip or a connector.

let us know what you find
I'm in Miami, if I can help, call me.

__/)_

 

[LavaASU]

***Assuming you have the knowledge/experience/training to safely troubleshoot electrical equipment***

Plugged in (to known good power), correct voltage, and good fuses is generally the best starting point for dead units. Typically after that I'd open it up and look for obvious damage (lose/broken wires/ pieces, burned spots, melted bits). At this point temporarily bypassing any thermal/interlocks *other* than lamp might be a good idea. Then I'd meter the AC going into the PSU. If that's good then meter the output of the PSU. If AC's good but there isn't correct low voltage from the PSU, then there's a pretty good chance that either the PSU or logic board is the problem (I'm assuming that if you're asking this you're swapping components as opposed to repairing them). Swap those with known good. If for some reason that fails to solve it there is probably some sort of interlock/safety that you weren't aware of or a combination of problems. Oh and don't forget to re enable the interlocks (they are there for a reason!).

 

[jhochb]

Good Morning Lava

The MAC600 doesn't have a PSU ( its very old ) It has a Transformer & a power section on the PCB to take the 3 AC voltages & make them DC on the board.

030366
You can unplug the connector from the PCB & meter the AC off the transformer but IT IS A LIVE CIRCUIT !!! Not recomended

The transformer often fail in the older fixtures.
Try this
Unplug the fixture.
with a quality meter check the resistance between the 0V tab and the other voltage taps on the primary side.
You should get something around 1.5ohms,3ohms, & so on, Very low resistance. It’s not uncommon for the 120 tap to fail.

On the MAC500 / 600 Martin used the primary side as an autotransformer to get 240V to the lamp circuit even when tapped at 120V. So there should be 3 or 4 wires on the primary side.
You can check the resistance with the wires in place.

let me know how it goes

 

[Esoteric]

Diagnostics is 90% of the battle. When I did service, I was level 3, which means I got the unit after two other techs gave up. As a result, I never had anything that was easy! There is a simple procedure used in service that would be a good place to start. It is called "divide and conquer."

Basically, you have two of the same units units with different problems. That is fortunate! Start by exchanging sub-sections to see what is leaving unit A dead. Once that is identified, replace it and then start the process of swapping and see which swap causes the "does whatever it wants to" to change units. Now you have identified both failed parts!

One word of caution. I once had a short in a wiring harness that blew out a PCB board. I thought it was a bad board, so I swapped a PCB board from a good unit. BOOM! Good PCB board was then a bad PCB board.

By the way, the talk of MAC600's as being old units is making me feel really old. I haven't done moving light repair in two or three years and all the units I did them on then were the "old style" like the MAC600's.

 

[LavaASU]

Good Morning Lava

The MAC600 doesn't have a PSU ( its very old ) It has a Transformer & a power section on the PCB to take the 3 AC voltages & make them DC on the board.

Haha-- I guess I should've mentioned I've never actually worked with a 600 so that was more of a general where I'd start with a dead mover than specific for the unit in question .