MAC 600 paer

[WiLL]

Hi chaps,

any advice appreciated on this one.

Recently had a Martin Mac 600 go 'a bit special' on me with colour changing difficulties and shuddering on reset and flashing a PAER (pan time-out error)

Popping open the head quickly showed me a broken Cyan wheel which is now replaced, however the panning error is stumping me.

The unit will find it's stop when panning anti-clockwise but when panning clockwise it doesn't recognise it's stop and keeps trying to run past it, resulting in shuddering and general unpleasantness until the unit decides it's had enough and sets a new 'soft' stop to enable it to function, trouble is this means it won't work on the plotted desk cues correctly.

I've opened up the base and made sure the sensor wheel and sensor are clean and the belt is in good condition. Swapping the pan and tilt leads over on the motherboard transfers the shuddering from pan to tilt so am I right in thinking that it could be a bad logic chip?

It's been an expensive year and I would rather avoid the hefty service bill of outsourcing this repair until I know it's beyond me.

Will

[mac.calder]

Test the wiring loom - probably slightly more likely to die than the logic chips.

[WiLL]

Test the wiring loom - probably slightly more likely to die than the logic chips.

One of the wires on the pan group close to the clamp is badly pinched, this is probably a suspect. Any reason why I shouldn;t attempt to cut out he break and clamp/solder this wire or should it be replaced entirely?

[mutley]

I always replace the entire set (six wires), including connectors. I figure that if one has broken, the chances are the others don't have long left...

 

You can get the connectors contacts and housings from CPC, RS, Farnell, etc. For a longer "life expectancy", you could use silicone insulated wire.

 

When you've done a few, you can get the whole process done in less than 30 minutes!

[Jamtastic3]

Mutley, do you know what the connectors are called to attach ribbon to stepper motors? I've got a disintegrated one and I can only find computer based connectors (like IDC's) on CPC's site

[mutley]

Housing

Contacts

silicone insulated wire (RS)

PVC insulated wire (CPC)

 

It will be one of the sensor wires that is broken, not the motor wires. To prove this, just pull on each of the wires (after cutting the cable ties off) and one or two of them will seem to stretch, because the wires inside the insulation have broken.

 

Also, check the screws on the opto-slotted disc to make sure they're tight. It's not uncommon for them to work themselves loose causing the disc to come off the spindle.

[jamieshurlock]

Hi Will, this is a common problem, there are a few answers to what the fault is as I have done a lot of mac repairs over several years...

 

I have re-read your post a few times so I'm presuming that when the unit starts up and tries to calibrate it does not judder until it reaches it's end stop?

If it is turning until it hits the end stop switch (which it does first) and stopping itself then that part of the circuit is working fine.

If it then turns in the opposite direction and will not stop itself then the problem lies with the optical position sensor.

This is what it looks like to me, the chances of it being a damaged loom is unlikely as the wiring for the pan is in the base with the main pcb but if you see damage to the connector then it may be the problem - use a multimeter to test for continuity and if necessary change the connector (or I may have a spare loom here)

 

You may find that the sensor itself is the problem and will need replacing.

Swapping the pan/tilt connectors is a good way of finding some faults (always do the swap with power off as you can damage the driver chip I.c.) it makes it look like there may be a problem on the main pcb but you must also remember that the sensors will not see the pan/tilt going to it's position as it should which can confuse the sensor circuit.

 

If the problem is not the optical position sensor or wiring then the pcb fault can be the driver chip, I would swap the actual chip over with the tilt one you know works and see if it makes any difference. - This seems unlikely though.

If the juddering is still present then it can be the surface mounted resistors that protect the chip, this is for competent soldering as it's not easy (I do these repairs a lot)

You could be very unlucky and find the smd chip (surface mounted) that runs the driver chip needs replacing which is advanced soldering and requires special soldering techniques and equipment.

 

Even the guys at Martin send pcbs away if it's that bad, I have had mixed results on this repair but there is always the lighting hospital or a replacement pcb but this is worst case scenario.

This is all based on not having it in front of me, if it was I could diagnose it in about ten minutes and with my many parts fixed in half an hour.

 

If I can help further it would be better to email me with any more questions : jamieshurlock@hotmail.com or sales@jamiesmagictorch.co.uk

 

Good luck!

jamie

[WiLL]

Hi chaps, many thanks for your replies,

To clarify, after swapping the connectors at the motherboard (pan and tilt) the problem is immediately transferred to the tilt function (which operated normally when plugged correctly) and conversely the pan function seems to operate well. I have done a temporary fix on the pinched wire near the pan sensor, just stripping back, twisting together and insulating the broken ends, in the spirit of diagnosis but this has had no effect. To be honest, having had no formal training I feel I am reaching the limit of what I can do here. I'm hands on enough to have replaced the broken colour wheel and reassemble, but electronics is not my strong point. I do have 3 other units so I could go down the path of swapping the sensor or wheel but the idea of tampering with a pcb when my soldering looks like something from the set of 'The Munsters' is a little daunting.