Soundlab Colourscan blown component replacement

[DMXBandit]

A couple of months ago when I had set up my rig and powered everything up one of my Soundlab Colourscans went up in smoke. I removed it from the rig and everything else worked fine for the rest of the night. During the gig I found time to remove the circuit board from the fixture and have a quick look. One of the components was completely burnt out, melting side of the dip switch block and damaging the track on the bottom of the board.

I've now decided I need all 4 scanners working again so I've been having another look at it. The burnt out component was a 22ohm resistor connected between the ground on the DMX input and ground on the board. Basically what I would like advice on is whether replacing this resistor will fix the unit, or if its likely that something else is at fault and caused it to burn out again. Before I removed the smoking fixture from the rig all the lights where flickering and moving randomly, but where fine after. Could it be the case that something was sending a high voltage down the DMX line?

 

Its about time I upgraded these cheap units to something more substantial, but that wont be possible for this next gig as its a charity event and I've already spent enough of my own cash on it, so if anyone has any ideas about possible faults that would be great!

 

Thanks,

J

[lightsource]

Follow the circuit path of the resistor, and see what components are next in the chain, before and after the resistor.

 

 

I'd probably not bother though........

 

In ours, there's been faulty pan/tilt motors, the colour wheels on some of them are cracked, probably because they can't take the heat of the lamp. Various cable faults, and on at least 2 of them, the focus lens falls out, if it's not taped down.

 

We started with 8, Now using 4 of them as spares, to maintain the others.

 

Oh, and when all 8 were working.....Starting a Jet aeroplane was probably quiter.

[DMXBandit]

Very true about the jet plane! I've had the stepper faults before and have probably replaced each of the pan/tilt motors.

The thing about tracing the circuit path is that the only thing its connected between is the ground on the DMX in/out and ground on the board which is, obviously, connected to everything else. The board is clean, there are no shorts or any corrosion anywhere.