Recent content by LanHell

This board does not use the VIC RAM addressing chip. It has discrete components on the board. (no daughterboard) Yes, I believe both were socketed on my board This board is running a Z80 ... totally possible. I built it late at night on a breadboard as a last resort for the night, and I'm...

I'd be all over these if I were closer heck of a deal!

Which voltages? Another user posted some info in a thread here that I found useful when fixing mine: https://forums.arcade-museum.com/threads/gremlin-dual-vic-power-supply-faq.423469/

Sorry, I didn't notice the note in the schematics saying either 1A-D or 2A-D... It looks like the signal should still be present at the unused pad, though.

You're not kidding about that one being tough to follow. Pin 14 of 2A-2D looks like it's a write enable line, and is generated by the 6Mhz clock at 8B pin 13... Check pin 12 of 1A-1D, and pin 2 of 1E&2E, you should have the same signal there

Still fighting with my Carnival. Finally got it to boot and appear to play, but graphics are all garbage blocks. I built an adapter to dump the 82S123 bipolar PROMs at U14 and U49 and found I don't quite match the MAME ROMs. MAME's 316-0206 @ U14 00 01 09 88 99 99 98 03 03 02 09 8D 9C 9D 9D 40...

The DS212 is so handy to just unwrap and check stuff quick. Usually all I need is to see is if a line is floating or noisy, and this (along with the ground extension) usually does fine for that. I didn't even consider that the scope bandwidth was too low, thanks for the tip. Sadly, I guess I may...

Am I right in assuming this is a bad crystal? I've checked the 330ohm resistors, the ceramic cap checks out close in circuit, and U13 seems to be inverting fine. I don't think there's anything else it can be, but I've never personally seen a crystal go bad before. Next question: Assuming the...

If the wheel is slamming at power on before the PC boots, your LM12CLK transistor (the big one on the heatsink) is shorted on the steering and lamp power board. Disconnect your steering motor (and/or unplug fuse F1 on that board) until you replace it, or you'll risk burning it out. If you find...

Try checking in Menu 6 (options) -> 0 (lockouts) to see if disc 21 somehow got added? If you find it in the lockout list, check menu 6 -> 9 -> 3. This setting will automatically add a disk to the lockout list when the number of 'skip occurrences' reaches the threshold. See section 2-40 of the...

It's looks like it's likely one of those caps causing my trouble. I'll order some up. Thanks!

I got a game a while back with a pretty badly acid damaged Bally AS-2518-35 MPU board. The main ground trace surrounding the board on both sides was nearly gone. After cleaning it up and sticking in a battery corrosion repair kit, pin headers, and recapping the solenoid board with parts from...

I've been googling around and have found plenty of color information for Ms. Pac-Man cabs, but can't seem to find anything for the regular Pac-Man yellow. Anyone happen to have the paint code, or any information on it? Sides are currently (badly) painted grey, with a 'pirate ship / port hole'...

I'm kind of a noob with vids. Didn't realize that's what that IC was.

Alright, I think I got it this time. I wiggled the IC's around on the PCB and found that when I wiggled 5S, it went away. Pulled the chip, and noticed the pins were pretty much black. So I cleaned the pins with an abrasive pad, popped it back in, and so far it's good. Thanks for the ideas guys.