High End Studio Spot 575 moving light.
This unit has started seriously failing to tilt, first symptons were noisiness when tilting which escalated to shudders during tilts or slow tilting, now the unit will be halfway through tilting when it will make a grinding noise as if the drive belt is slipping, shudder, and then quite pitifully attempt to reach the desired tilt like a man dragging themselves up a steep hill when both of his legs have been broken. It is effectively useless at present and I've just spent 2 hours fixing cue lists to remove the unit from a show as I have no replacement .Before I send it off for repair I was wondering if anyone has any simple fix solutions.
I've made sure the sensor wheel is clean and free from dust, the belt appears to be in good shape and I've observed the unit doing a tilt test with it's covers off and the belt doesn't slip. The noise seemed to be emanating from within the body of the lantern but I'm loathe to dissassemble Johnny 5 on it as I've never had any formal training in that area.
Incidentally the fault persisted during the tilt test too.
Any suggestions gratefully received, if all else fails it's going in for repair later this week.

One of our EVL ProSpot575 makes the same noise when hung but is fine when on the floor. Would be interesting to hear your solution as I can't see anything obviously wrong with ours either.

Hi

Just a guess, but it sounds like the one side of the tilt stepper driver has blown, so only half the motor's core is getting power. I've seen this problem on a few heads (most notably MAC500s) and a new chip has always fixed it straightaway.

HTH

All the best
Timmeh

try swopping pan and tilt connectors on the main circuit board first. then try swopping the stepper driver chips, I have also had the pre driver chip cause this exact same problem, and it was soldered in so quite difficult to replace.

And of course the loom is suspect as always

[quote name='timmeh2' date='8 Feb 2010, 10:12 PM' post='330834']
Hi

Just a guess, but it sounds like the one side of the tilt stepper driver has blown, so only half the motor's core is getting power. I've seen this problem on a few heads (most notably MAC500s)



I second that we had the same problem on a varilite we had to replace the entire the motor.

How's the motor feel? With power off-- you should be able to feel the steps and the feel should be consistent. With power applied it should have a reasonable amount of resistance. Compare with a known good motor.

You say the problem seems to be in the head-- on this unit is the tilt motor in the head or the arm? Have you watched with the head covers off or just arm? I haven't worked on this particular unit, so I don't know quite how it's laid out, but this is how I'd approach this problem for whatever mover.

My experience with carrying our repairs on moving heads isn't huge as I said but I'll do my best to answer questions after I've dropped the unit to the ground again tomorrow morning and tried the suggestions made so far to diagnose the problem. Thanks for responses so far chaps.