I had a 20M4U shipped to me, I know it's not the greatest idea but I've had a 20M2MDU shipped to me and it turned out fine so I decided to roll the dice again. It arrived today with no visible damage outside but I turned it on and was greeted by this (that's not the photo, it really is bright blue in addition to the visible raster lines, and also kind of flicks between different shades of blue):
I performed a factory reset and tried degaussing (via the degauss button) which had no change. To my eye internally it seems fine:
I was shown pictures of it working correctly before buying so I'm pretty sure this happened in shipping. I've checked that all cable connections are seated correctly. Does anyone know where I should go from here to troubleshoot this?
Same problem with a console is hooked up?
75ohm terminators on the outputs? (I've never used my RGB monitors without those but I read it fixes issues with RGB levels or something, not sure how it looks like without the terminators.)
Maybe a pot like screen/G2 has rotated slightly?
Hopefully the tube wasn't damaged on its way...
Sorry, trying to help with my limited knowledge
That's the kind of image you get if you short one of the neckboard transistors to ground. Those are the ones in the little metal heatsinks, i would guess, but PVM's are much more complicated than arcade monitors or consumer CRTs. Normally i would say you can test the other colours the same way to see if the image changes, and then see if activating the blue one makes any difference. The cause would be a faulty transistor. In this case i'm not sure.
