Sam_Lowers Posted November 27, 2009 Share Posted November 27, 2009 Hi All I have a show on this week using MAC 500’s in mode 4. They have both been fine all week until last night.One of the units has started playing up and wont reset it’s self to its home position properly. This is not so much of a problem because it is accessible and a manual reset can be done directly on the unit. The other has started to play up. I have a feeling that there may be a problem with the cooling on the unit. The fans are all clear but the unit has started to overheat so won’t open the shutters at the right time. It is a strange one though as there is a 575 wash by this unit that is fine and the Mac is in one of the coolest places in the rig. I couldn’t find it in the manual but do MAC 500’s have variable fan spend – can they be set to high? If so can someone write down on how to get to this option? I have to admit that I am not a regular user of MAC 500’s as I usually use Robe 575AT’s instead. If someone can get back to me ASAP that would be great so I can try and rectify it before the show goes up tonight! Thanks Sam Link to comment Share on other sites More sharing options...
Wol Posted November 27, 2009 Share Posted November 27, 2009 Is it not something to do with studio mode on the macs, where if you run them in normal mode, they run the fans faster, but noisier? Its in the bit about the menu in the manual. You should be able to get a readout of the temperature on the device too through the menu (again, documented in the manal). What temperature is it currently running at? Link to comment Share on other sites More sharing options...
Ben Posted November 27, 2009 Share Posted November 27, 2009 Most likely just to be a faulty temperature sensor but without further investigation all any of us can do is guess Link to comment Share on other sites More sharing options...
Sam_Lowers Posted November 27, 2009 Author Share Posted November 27, 2009 Thats what I was thinking, this is why I was hoping you can crank up the fans like on the Robes. I suppose the only other thing possible would to put a desk fan blowing onto the unit to try and cool it! Link to comment Share on other sites More sharing options...
Ben Posted November 27, 2009 Share Posted November 27, 2009 Thats what I was thinking, this is why I was hoping you can crank up the fans like on the Robes. I suppose the only other thing possible would to put a desk fan blowing onto the unit to try and cool it! If its a faulty sensor this is unlikely to help as they will normally be fixed in one position, the only thing to do would be swap the sensor Link to comment Share on other sites More sharing options...
Sam_Lowers Posted November 27, 2009 Author Share Posted November 27, 2009 This is what it really confusing me. I have full controle over everything but the shutters! Link to comment Share on other sites More sharing options...
timmeh2 Posted November 27, 2009 Share Posted November 27, 2009 Hi Just a few pointers. The head temperature sensor won't shut off the lamp if it reads too high - its purely the bimetallic switch which controls it. This is a shortcoming in all the old macs, including the 250, 300 and 600. Also the display will only read up to 100 degrees. If you're losing shutter control when the unit gets hot I'd suggest that the wiring to the steppers is faulty. A typical fault with older units is that the insulation becomes conductive as it is heated up. As has been mentioned before make sure that the unit is not in Studio Mode which halves the fan speed. A quick way to tell is if it pan and tilt speed is slower than the others. As an aside if a mac ever flashes up HTER then lamp off immediately - the +12v DC rail that supplies the temperature sensor also powers the fans, so this error sometimes means that your fans have stopped working. This will cause catastrophic damage to the wiring and other internal components, usually before the bimetallic switch has a chance to shut down the lamp. HTH All the bestTimmeh Link to comment Share on other sites More sharing options...
Ben Posted November 27, 2009 Share Posted November 27, 2009 This is what it really confusing me. I have full controle over everything but the shutters! What exactly is the unit doing? what messages are showing on the units display? Link to comment Share on other sites More sharing options...
Sam_Lowers Posted November 27, 2009 Author Share Posted November 27, 2009 I'm afraid I havn't had a chance to look into the screen as when it failed was during the show. When I got a chance to get upto the unit after the show it was all working again! Hence why I thought it may be somthing to do with the heat Link to comment Share on other sites More sharing options...
Ben Posted November 27, 2009 Share Posted November 27, 2009 I'm afraid I havn't had a chance to look into the screen as when it failed was during the show. When I got a chance to get upto the unit after the show it was all working again! Hence why I thought it may be somthing to do with the heat Could this just be a control issue if its just at certain times you cant get shutters working? Link to comment Share on other sites More sharing options...
Sam_Lowers Posted November 28, 2009 Author Share Posted November 28, 2009 No checked all the controle settings and according to the desk it should work! Link to comment Share on other sites More sharing options...
Ben Posted November 28, 2009 Share Posted November 28, 2009 Are the units hired? Link to comment Share on other sites More sharing options...
KevinE Posted November 28, 2009 Share Posted November 28, 2009 If a moving head loses its shutters when warm, it's often just another symptom caused by overheating, since the shutter is usually the closest thing to the lamp and usually overheats first, seizing or going stiff. This happens in many brands of head. Maybe if you sort out the overheating first, the shutters will be ok. Link to comment Share on other sites More sharing options...
Ben Posted November 28, 2009 Share Posted November 28, 2009 If a moving head loses its shutters when warm, it's often just another symptom caused by overheating, since the shutter is usually the closest thing to the lamp and usually overheats first, seizing or going stiff. This happens in many brands of head. Maybe if you sort out the overheating first, the shutters will be ok. This is working on the assumption that the head is over heating to start with, as the OP has not checked the temp at all and the only problem is the shutters not responding the problem may well be one of the motors or cables not being good as the unit itself may be within the normal operating temperatures. The Problem here may be over heating but also may not and without a little further investigation all we are doing is guessing. The chances are if you are certain this could not be a control issue that it is a heat problem but that does not necessarily mean that the unit is over heating or running hot it may just be that the parts are past their best. Let us know what the screen tells you and we can help further diagnose this. If you get stuck when with the unit give me a call and I will be happy to advise you over the phone. Ben Link to comment Share on other sites More sharing options...
thelxbloke Posted November 29, 2009 Share Posted November 29, 2009 I'm an ex moving lights tech for a hire company who used to deal with a fleet of mac 500's. Chances are this problem is not down to over heating but down to the magnetic alignment on the col1/gobo1 wheels.What tends to happen with this is that the fixture resets fine and will run fine for a while and will then randomly close the shutter, and attempt to re-home these wheels. The best way to check if this is the case is to hang the fixture with the covers off and run some chases with the col and gobo wheels going at the same time and leave it on for a while and watch it. The way to fix this is in the service manual which I don't have to hand but if you find this is the problem I might be able to get hold of a copy for you. Hope this helps you Steve. Link to comment Share on other sites More sharing options...
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