Virtua Cop 2 - Mid Res Monitor Rebuild

[Derrick Renaud]

Just thought I'd post about my success rebuilding the 26" monitor in a Virtua Cop 2 Cab.

The old monitor had severe burn-in.  There was no white, only brown and browner.  There was vertical colapse, retrace lines and 60Hz hum.  The guns would not register anywhere but the center of the screen.

It used an Nanao MS8 chassis. I replaced all the caps.  30 or so.  All were bad/leaky except the 1uF, 50V, which I replaced anyways.  Now I had full screen and a semi-decent picture.  But the burn-in was still causing the guns not to register.  You just could not get the screen white enough.

Time to replace the CRT.  Out with the A63LCC61X tube.  Time to gut a Sharp TV Model CC26S20 with a A63AEH20X tube.  Sharp tubes are great because the yoke is removable.  All RCA/GE TVs have a bonded yoke, that I had no success removing while leaving the neck on the tube.  

The yoke on the Sharp TV was made for 15Khz, and the Virtua Cop uses 25Khz, so you definitely have to swap yokes.  Of course that means you need to do a full Purity/static alignment on the CRT, and Virtua Cop 2 has no test patterns for that.

Well, if you go to gun test mode, it puts out a nice white screen.  Short the Base/Emitter connections on the final Blue & Green drive transistors on the kine board, and you now have a red pattern allowing you to align the purity.  With that done, it was a small matter to use the grid test pattern in test mode to align the static geometry (neck rings) so all 3 colours align.  Then use the same pattern to align the H/V size/position.  (Actually you need to do a quick course adjustment of these before doing the purity.)

Success, I now have a nice picture with no burn-in and good whites.  The guns mostly work now.  There is still a problem with black bars rolling across the screen, which means I need to check the caps in the game power supply and on the game boards. I'll get to that next week.

This cab is a repair at work, not mine.  I just thought people would like to know that the arcade monitor CRTs can semi-easly be replaced with TV CRTs if needed.  So do not throw out that old TV before checking if the neck is bonded or not.  Bonded means throw it out.

[Derrick Renaud]

I fixed the rolling bar interference in the picture.  I added ground wires from the Arcade Monitor chassis metal brackets to power supply ground.  1 on each side of the bars near the kine board.  Drilled a small hole in the brackets and used self taping screws.

Picture now looks great.  This might be something to try if you have interference on your own arcade monitor.

[lilshawn]

thanks for the updates! I'm always glad to hear about things being brought back from the dead.