Dynamo 250 Lights - Power Problems

[DJ fixer 0]

Hi there

 

Dynamo 250 playing up which looks like power supply problem.

 

The bulb (Osram 24v) will light up then after an interval varying from seconds to minutes will go out. After switching power off it will sometimes light again, but not always.

 

The gobo and mirror motors have also stopped working.

 

I checked output from the two transformers and neither is outputting any power. One common factor as far as I could judge with my limited electronic knowledge looked like it might be a relay (Sanyou SJ-S-112DM) on one of the PCBs which seemed common to both light and motor circuits, and which I guessed might not be switching the power when it should. I tried changing the relay with an equivalent one from RS (stock no 719-6341), the Sanyou relay no longer being easily available, but it made no difference.

 

I suspect it would be unusual for both transformers to fail together so am assuming some other cause, other than what I have tried. Any suggestions would be most welcome. Many thanks.

[McCardle 1]

I checked output from the two transformers and neither is outputting any power.

 

Unlikely to be both Transformers failed, unless its taken a jolt from a lightning surge or something major. How are the primary windings (mains side) of the transformers wired?. Do they go through any voltage selector switch?. On the mains input socket, does the socket have a built in fuse carrier?, these can get damaged or the contacts work loose sometimes, so it may be worth metering the back of the mains input socket to see whether you are getting mains voltages out.

 

Are there any LED's lit at all on any control PCB's?

Edited July 5, 2014 by McCardle

[DJ fixer 0]

No mains selector switch fitted. Mains cable goes direct into the transformer for the motors (12v output), and via the PCB containing the aforementioned relay to the light transformer (output 24v). There is power coming from the input socket.

 

There is a fuse on each of the 2 PCBs; both are intact. There is no fuse on the input socket.

 

There is 1 LED on the PCB with the relay - it lights up.

 

Apart from that, the only thing that works when the power is switched on is the cooling fan for the bulb.

[McCardle 1]

Obvious question, but if there are DMX assignment DIP switches on the rear panel, are they all switching correctly, and non of the individual switches 'stuck' between on and off or damaged in any way?. I had this on a Datamoon once, where the DIP switch was damaged internally preventing stand alone operation to be selected and so the effect did nothing as it was waiting for a DMX signal before the relay would switch on the lamp.

 

A damaged or loose DIP switch or a bad joint on the PCB, could also probably explain why the problem was intermittant before.

 

If there is an LED illuminated on the PCB, then obviously there is power coming from at least one of the Transformers

Edited July 6, 2014 by McCardle

[DJ fixer 0]

All DIP switches look as though they are working correctly. None are damaged nor stuck in an intermediate position.

[DJ fixer 0]

I've given up on this, so unless I find some inspiration this unit is going into the spares box!