So I visited the arcade of someone I have come to know and while taking a look around and playing a few games, I stumbled across this screen on a Frogger:
Not exactly playable, if you catch my drift. Went over the usual stuff, power, reseating, etc. Voltage was a little low, and the power supply could use some maintenance because of a bit of ripple. But was able to get it back up again. When it booted, it booted into an odd screen and I realized it had some kind of HS kit in it. This was actually nice because it included a RAM and ROM test that showed everything passed.
Went into the game and coined it up to play, and saw this:
Pretty sure that we do not want that many lives per game. Seeing that this was a pretty strange issue, I thought to reconfigure things in the HS kit. After readjusting things to 3 lives per game, saving the changes and restarting the game:
Much better, eh?
After fixing something, always be sure to actually try to play it and make sure everything is working right.
Got an interesting problem with a Roc’N Rope board that I recently connected up to the new JAMMA test rig. It has all its sounds, and plays correctly, but the text and tiles (e.g. the title graphics and the graphics used to build the levels) are all upside-down!
When the screen is flipped for cocktail mode, the text/tiles are still upside down.
Going digging through the schematics to see what’s what…
Mark Spaeth gave me a lead on a couple chips on the board that may be the cause of the problem. That, combined with the schematics lead me to find out that I had a 74174 with a stuck output (pin 10). I first clipped and lifted the pin for that specific output to ensure that nothing else was pulling the output and confirmed that the chip was bad.
After clipping and desoldering the chip and replacing it with a socketed NOS 74174, all of the text and tiles are right side up again!
Also, I found out that I have another RnR board, this one with a graphics issue involving the sprites. Should be able to get that one fixed as well, and then I will have two original RnR boards (both with their original serial number stickers on ’em).
OK – this other RnR board just had to have some of its chips cleaned and/or reseated. It is looking good now as well:
Nutshell: Flipped tiles and text, cause was a 74174 at location G15 with a stuck output @ pin 10.
Boots and passes self-test, but immediately coins itself up and starts playing itself(!), although not too well.
Well, it looks like some of the inputs are firing rapidly and randomly. Grounding one of the enable pins on one of the 74LS253s seems to make it settle down for a few seconds, so I will try playing with it.
[07/30/03] Update #1: OK, it looks like one of the outputs (za) is always low on the 74LS253, regardless of its inputs. Will try swapping it out.
Solution: None yet.
Random garbage (no sprites) and occasional random sounds, reboots randomly. Clock looks good, CPU and bus address and data lines have what appears to be otherwise normal activity (i.e. nothing appears stuck or floating). Pulled EPROMs and Romidented them; Romident does not identify all but 2 of them, and the two that are identified are not identified as Kicker ROMs!
OK, so I pull the EPROM archive for Kicker, and match them up that way. Three of them match up, four do not. Hmmm… One of the EPROMs does not erase(!). Going digging for a replacement…
Solution: None yet.