Ashley R Posted May 15, 2013 Share Posted May 15, 2013 Hi All Got a troublesome Futurelight MH660 here, which just refuses to give up on its heat error status. a few days ago, it threw up a heat error, so I swapped out the Heat/ Light sensor PCB with a brand new one from Robe. Rigged the fixture and powered it up a few times and all was good, so it was then hung in a rig. Few days later, Heat appeared again. Now its back on the bench, and I tried playing with the sensor again to no avail. The unit almost goes through its full Reset functions on start up, before heat appears. Checked all the wiring, and its showing continuity through from the Sensor PCB to the arm PCB. So I am a bit stumped on this one. Hoping someone has a magical answer. Also no one here would happen to know which pins on the arm PCB, relate to which pins on the sensor PCB, as I just dismantled it, and smudged off my sharpie markings on the cables! Link to comment Share on other sites More sharing options...
ninjadingle Posted May 15, 2013 Share Posted May 15, 2013 HEAT shows up when you try to lamp on less than 5 minutes after you have lamped off (once the 5 minutes have elapsed the unit will automatically lamp on for you), or when the lamp hasn't ignited after 28 seconds. Tried a new lamp in there? As for pins - tried looking at the Service Manual? Link to comment Share on other sites More sharing options...
Richard CSL Posted May 15, 2013 Share Posted May 15, 2013 If heat is appearing as soon as reset is finishing, this is actually indicating that the heat build up is immediate, have you checked the fans and the air flow? Failing that have you swopped the lamp with another fixture?, as lamps age they blacken and can produce much higher heat at source. especially in the final stages of lamp life. check the balast connections for any signs of arcing or overheating connections. Is the pf corrector capacitor showing any signs of ageing? If you have changed the sensor, logic dictates that heat build up is occuring, so find the cause check the above, then report back. Link to comment Share on other sites More sharing options...
Ashley R Posted May 15, 2013 Author Share Posted May 15, 2013 Fixture has been allowed to cool before re-striking. Already tried a brand new Phillips MSD 250/2 lamp, from a different batch of lamps that the one that is in there came from, as I only replaced the lamp 100 hours ago. From preliminary inspections, all fans, surfaces etc. are relatively free from dust and dirt, and fans are running at Max Speed. I shal check the ballast and the Cap. Link to comment Share on other sites More sharing options...
Whizzzy Posted June 3, 2013 Share Posted June 3, 2013 As a suggestion check the blue / black wires which connect from the ballast and pf capacitor in the base up to the connector block at the top of the yoke arm. One of my units was exhibiting a similar fault, the unit would run through its reset and show 'heat' immediately afterwards. Changing the usual components such as the photo-transistor, lamp, starter, pf cap didn't bring any results so resorted to metering out the wiring. Gave the lamp wiring a firm tug just where it enters the yoke and it just broke away. Replaced the wiring and it's up and running again. Link to comment Share on other sites More sharing options...
ChrisBogg Posted June 4, 2013 Share Posted June 4, 2013 We had a stock of these and the lamp on light sensor dies on them. Give robe UK a call and talk to Nathan or one of the guys. they built these units back in the day. The parts are buttons if it is the sensor and sounds like the kind of fault we used to get. Chris Link to comment Share on other sites More sharing options...
Don Allen Posted June 5, 2013 Share Posted June 5, 2013 Futurelight 660 service manual Brians Futurelight service manuals on BR Link to comment Share on other sites More sharing options...
serious_sound&light Posted July 7, 2014 Share Posted July 7, 2014 If the lamp strikes, then goes off after a few seconds and the HEAT message comes up, that indicates that the sensor or its wiring is not working. If the lamp does not strike, this could be the relay (does it click on and off?), ballast, igniter or lamp. The PF cap is there to correct the mains power factor and will not play a part in preventing the lamp striking. The signal to close thd relay comes from the control panel pcb on pin 7, goes through a surface-mounted relay driver transistor underneath the main pcb and drives the relay. The wires between the pcb and lamp sensor photodiode are prone to breaking between the head and yoke pcbs. This would cause the lamp to shut down with the HEAT error if it is struck in a certain tilt position, but not always. Link to comment Share on other sites More sharing options...
serious_sound&light Posted July 7, 2014 Share Posted July 7, 2014 Something I learned today was that the Robe ct/xt moving heads ( MH660/640 /Coemar ProSpot are all Robe designs) no longer use a photodiode to monitor the lamp - they monitor the voltage across the ballast instead. More reliable, but it means the main boards are not interchangeable. Terminal block SVi on the ct/xt models has an extra pin labelled 'SENS' and there is no connection for the photodiode. Link to comment Share on other sites More sharing options...
serious_sound&light Posted July 8, 2014 Share Posted July 8, 2014 Something I learned today was that the Robe ct/xt moving heads ( MH660/640 /Coemar ProSpot are all Robe designs) no longer use a photodiode to monitor the lamp - they monitor the voltage across the ballast instead. More reliable, but it means the main boards are not interchangeable. Terminal block SVi on the ct/xt models has an extra pin labelled 'SENS' and there is no connection for the photodiode. Link to comment Share on other sites More sharing options...
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