DrRusty Posted December 17, 2017 Share Posted December 17, 2017 Hi I assist with a local dramatics group putting on a panto each year. We have lacked a follow spot and this year we obtained an ifollow 575. However, although I was assured it was fully working the dimmer refuses to work. I can get "full" or "off" but the dimmer control has no effect. Other controls seem to be ok. I have also tried a separate DMX controller, but still no dimmer function. I can see nothing obviously broken or damaged inside the case. If anyone can provide some advise I would be very grateful. Link to comment Share on other sites More sharing options...
timsabre Posted December 18, 2017 Share Posted December 18, 2017 Almost certainly the triac in the dimmer has failed... Not user-fixable Link to comment Share on other sites More sharing options...
Mazz Posted December 18, 2017 Share Posted December 18, 2017 A quick Google shows various followspots with the name "iFollow 575" and they all appear to use discharge lamps, so presumably they have some kind of mechanical dimmer shutter ? Link to comment Share on other sites More sharing options...
DrRusty Posted December 18, 2017 Author Share Posted December 18, 2017 Yes, the lightbhas a discharge lamp and mechanical dimmer. Using the dedicated controller there is a button to fully open the shutters, which works. I can also use an offset function on the spot itself which brightens and darkens the spot. However, using the dimmer control slider has no effect. Link to comment Share on other sites More sharing options...
timsabre Posted December 18, 2017 Share Posted December 18, 2017 Yes, the lightbhas a discharge lamp and mechanical dimmer. Using the dedicated controller there is a button to fully open the shutters, which works. I can also use an offset function on the spot itself which brightens and darkens the spot. However, using the dimmer control slider has no effect. Doh should have looked it up before making a stupid answer. It's a goldenscan ripoff isn't it ... so could be a stepper motor fault? If you look inside (with the lamp off so you don't get arc eye) can you see the dimmer shutters? Link to comment Share on other sites More sharing options...
DrRusty Posted December 18, 2017 Author Share Posted December 18, 2017 I have looked inside with the unit completely off and I can see the dimmer shutters and stepper motors. I am starting to feel this light is a lost cause and probably not worth repairing :-( Link to comment Share on other sites More sharing options...
Brian Posted December 18, 2017 Share Posted December 18, 2017 I can also use an offset function on the spot itself which brightens and darkens the spot. However, using the dimmer control slider has no effect. So if the full on/off buttons work, but the slider doesn't, it sounds like the motor and mechanics work but the slider is faulty. This could be as simple as the slider has been bashed or a wire has dropped off. Both simple fixes. Link to comment Share on other sites More sharing options...
timsabre Posted December 18, 2017 Share Posted December 18, 2017 So if the full on/off buttons work, but the slider doesn't, it sounds like the motor and mechanics work but the slider is faulty. This could be as simple as the slider has been bashed or a wire has dropped off. Both simple fixes. He said it didn't work on DMX either... though there could be other problems there. It'll definitely be fixable and probably not a very difficult fix, it depends on your skill level in dismantling stuff. Link to comment Share on other sites More sharing options...
DrRusty Posted December 18, 2017 Author Share Posted December 18, 2017 Timsabre I am probably capable but it is a case of knowing what needs fixing first. So far simple obvious fixes haven't worked. I really had thought the fault was the slider and so tried an external DMX controller. However, that just confirmeconfirmed the fault was inside the unit after all :-( I read there can be an issue with the motor control IC. That might be an easy fix (proof of fault) as I could swap out a chip from another channel. Timsabre I am probably capable but it is a case of knowing what needs fixing first. So far simple obvious fixes haven't worked. I really had thought the fault was the slider and so tried an external DMX controller. However, that just confirmeconfirmed the fault was inside the unit after all :-( I read there can be an issue with the motor control IC. That might be an easy fix (proof of fault) as I could swap out a chip from another channel. Brian, checked all wiring nothing obviously broken or disconnected. As the an extenral DMX controller didn't operate the dimmer I am now convinced the fault is inside the spot not at the control (well excluding it is both). Link to comment Share on other sites More sharing options...
timsabre Posted December 18, 2017 Share Posted December 18, 2017 OK so you said that the full on / blackout button works - is that using the same motors/shutters as the dimmer or is there a different mechanism for that? When the unit powers up, you should see the all motors run briefly to an initialisation position. Also if you poke the shutters with the unit powered they should feel "notchy" as the stepper motor jumps between its phase positions. With the power off the shutters should move smoothly with a very slight notchiness from the motor. If you can identify the motor output on the mainboard which is controlling the dimming shutters, you can swap it on the electronics board for another motor (eg colourwheel). That will test whether it is the motor controller IC or the motor. I've never fixed one of these units, but on other units the dimmer shutters are right next to the lamp and this can cause them and the stepper motor(s) to get very hot if the unit is left running with the shutter closed. The motors then gum up and feel really gritty or sticky (with the power off). Link to comment Share on other sites More sharing options...
niclights Posted December 18, 2017 Share Posted December 18, 2017 As far as I can see these fixtures have a very similar appearance to the Clay Paky Shadow (and the various Clay Paky moving mirror fixtures that these are also common to). If it's the same inside then there will probably be a pair of direct-drive blades near the front of the unit that perform both the dimming and shutter functions. When dimming they move together and when strobing they alternate. I'm making a lot of assumptions of course but if I'm correct then it can't be the motors. This a link to the 1200W version of the only match for 'iFollow' I could find:iSolution iFollow HMI 1200 Followspot product pageLink to manual for 1200 and 575W models According to this there is a dimmer calibration setting. It seems unlikely this could have been adjusted in such a way as to prevent dimmer but retain shutter but I would suggest is worth checking first if you haven't already done so. Link to comment Share on other sites More sharing options...
DrRusty Posted December 18, 2017 Author Share Posted December 18, 2017 njclights and timsabre Thank you for the helpful advice. Yes I saw two "blades" at the front which I deduced were the shutter for the dimmer function. Each blade has a separate stepper motor. I found the "calibration" setting (refered to as offset). This seems to work as increasing from -127 a light is projected from the lens. Which in a way suggests the blades are working. If I can figure out which IC controls the dimmer function I might start by swaping it out with colour or light temperature controller. njclights and timsabre Thank you for the helpful advice. Yes I saw two "blades" at the front which I deduced were the shutter for the dimmer function. Each blade has a separate stepper motor. I found the "calibration" setting (refered to as offset). This seems to work as increasing from -127 a light is projected from the lens. Which in a way suggests the blades are working. If I can figure out which IC controls the dimmer function I might start by swaping it out with colour or light temperature controller. Link to comment Share on other sites More sharing options...
DrV Posted December 18, 2017 Share Posted December 18, 2017 You'd expect that if the calibration was all the way down at -127 then its neutral point is 0 and that might be all that's wrong. If that function operates the blades correctly and if they are able to move from off to full by means of the other control then it does sound like a simple calibration/setup fault Link to comment Share on other sites More sharing options...
DrRusty Posted December 19, 2017 Author Share Posted December 19, 2017 You'd expect that if the calibration was all the way down at -127 then its neutral point is 0 and that might be all that's wrong. If that function operates the blades correctly and if they are able to move from off to full by means of the other control then it does sound like a simple calibration/setup fault I was having the very same thought driving into work. I will have to try this again using the deidicated and separate controllers. Thank You Link to comment Share on other sites More sharing options...
DrRusty Posted December 20, 2017 Author Share Posted December 20, 2017 I seem to have dimmer control, albeit shutter has to be fully on as well (I can't remember if I tried this before. Anything less than full and the shutter sttobes, which is not an effect I will need. Obviously, the best news was that the stepper motors work. Colour temp is off, but it should hooefully only be a case of getting the calibration setting correct. Still on a steep learning curve but feeling more confident Thank You Link to comment Share on other sites More sharing options...
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