Trying to finish up this cocktail cab for a friend. Here is the problem. When I close the lid the colours start to go off. I am certain it is a electromagnetic field issue and almost positive it is coming from the isolation transformer. Any suggestions?

Have you tried moving the cab around?  Sounds stupid but it worked for me when I had one.  I put it in a different spot/orientation and it cleared right up.  The other thing you may need to do is degauss it (with a real deaguassing coil - not the built-in crap)..

Also, did you turn on the machine with the cover closed or open?  If you change the orientation of the monitor - i.e. close the lid - AFTER the built-in degausser fired, you'll get funky colors.  The monitor has to be off for at least 5 mins for the degaussing circuit to activate on power-on.  

Mike

Ah... you can't fix that... sorry... cab is dead... you can sell it to me if you want!  



First, like previously noted, degauss the monitor.

Second thing, is it near an outlet? It is possible that you are getting EMF interference from the house wiring. Move it around like Mike said.

#3, a nice sheet of fish paper board around the transformer often deflects the EMF enough to solve the problem.

or

#4, a steel cage around the transformer... I have gutted a few old Bally pins for parts and I always keep the transformer covers from pins that had the transformer in the head. They can scramble the EMF enough to help out.

or

#5, overkill... wrap your transformer with Mu-metal (very expensive). I do this on heavy machinery CPUs when they work in foundaries where the magnetic fields are well over the value of a hand magnet. Works wonders, but hard to find.


Sparky

We had this same problem with a cocktail that cooke had. We ended up changing out the iso transformer for a different one to solve the problems.

Other than f'ing up my picture, and satisfying some code (yeah, like a homebuilt unit is going to meet CSA and ULC standards ) what is the iso transformer doing for me?

It allows your monitor to run without blowing itself up. It's pretty much a must-have unfortunatly.

Well if that's the case then which transformer did you use in cooke's cab. I played around positioning the existing one but I think I am going to have to find one that doesn't generate that much EMI. Before I jump into that does the boardset generate enough EMI to be creating a field effect?