Qbert

I got this from a trade with a local collector. The cabinet was solid, artwork had its shares of cuts and scratches and the game was semi-working. The game displayed the graphics upside-down and a verticle split in the screen. It produced the "I'm turned on" voice upon power up and made a tone when the test button was pushed on the sound board.

I noticed that the game would reset if the power cord was wiggled so I replaced that with a new one. I also found out that the game would reset when the back door was closed. While the door was open I wiggled all the connections one at a time and was able to recreate the problem. Closer inspection of the filter board revealed several cracked solder joints.

Mike's Arcade - Q*bert

I reflowed and added solder to all the header pins on the filter board. I also inspected the header pin solder joints on power supply board which looked good as well as reseating all socketed chips on the CPU board. I replaced the board and powered the game on and it seemed more stable but still had the video issues. I was able to wiggle the connections and close the door without it reseting.

Next I inspected the power supply board. All power LEDs were on so that was a plus. I checked the voltages on P3 (using pin 5 as ground) and had the following results:

• Pin1 13.7v (should be 20v)
• Pin3 -11.7v (should be -12v)
• Pin4 12.2v (should be 12v)
• Pin6 32.0v (should be 30v)

Voltages at P4 (using pin 1 as ground):

• Pin16 5.3v (should be 5v)

Voltages at P1 (using pin 4 as ground):

• Pin1 11.65vv (should be 11.5v)
• Pin1 11.65vv (should be 11.5v)

I also tested the resistors with the following results:

• R12 102 ohm (should be 100 ohm)
• R13 13.6 ohm (should be 12 ohm) ***burnt***
• R14 14.3 ohm (should be 12 ohm)

I pulled the CPU board to inspect it closer and noticed that the 3 74LS377 chips at A8, A9 and A10 where missing. I checked the schematics and seems that they control veritcle flip and horizontal flop. I posting to KLOV repair forums confirmed that this could be the root of my video issues.

A parts order to Mouser was put in for the 74LS377s and some other parts.

Update 16MAY09...

Well I put sockets and 74LS377's on the CPU and the screen is now right-side-up but still split..

I recapped the monitor to no avail. There is an arcade party at a fellow collector's this coming weekend and he offered to take a look at the boards and monitor.

Well Mike (Riptor) ended up fixing my Qbert boardset. I ended up trading to a fellow collector so he can work a trade for a game he was looking for. I'm such a nice guy. Too nice sometimes.