ms. pacman stand up display backwards?

darrenz

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im thinking about buying off a guy.... states that it plays but everything is displayed backwards.ive worked on a few games before but its been a while. is this as simple as a switch on game board? i cant fully remember but i relaced a monitor board on a game before and i cant remember if screen was backwards but when i called company i think they had me cut the 4 prong plug in half and had me reverse two of the wires to solve whatever issue it was. any info would be great. thanks
 
You just need to swap the polarity of the windings in the yoke. Super simple to do. Someone probably replaced the monitor with one from a game that had a mirror in it.

-Ian
 
ahhhhh

ok i think thats what happened that time i swapped that monitor board.......do you recall wheater i swap the red and blue? or yellow and brown? thanks much
 
Mine was a board issue, cold solder joints I believe.

149.jpg

145.jpg
 
ok i think thats what happened that time i swapped that monitor board.......do you recall wheater i swap the red and blue? or yellow and brown? thanks much

Depends on exactly how you mean it's "backwards." If the scores are at the proper end of the screen (top as you view it) but everything is mirrored left-to-right, then you need to switch the vertical windings. Yes, the vertical windings, because in monitor-speak, "vertical" is always the "short direction," regardless of the orientation the monitor is mounted. Vertical yoke windings are typically the pair that ARE NOT red/white or red/blue; so in your case should be the yellow/brown pair. As was mentioned, verify continuity before switching any pair. And the resistance should be over 10 or 12 ohms for the vertical windings. If it's less than 10 or 12 ohms, you've got the horizontal windings.

Oh, and I'd just a tiny screwdriver and release the pins from the connector housing and re-install them reversed, rather than cut and splice the wires. Or if they aren't soldered at the yoke (i.e. if they have QDs) just swap them there.
 
thanks everyone

ill know more tomorrow when i go check out. but sounds like monitor came from a mirror unit. he didnt say distorted or anything, just backwards.ill check the ohms. oh and i didnt mean cut wires just cut plastic in middle of 4 prongs basically creating 2 plugs. thanks much. ill keep ya posted.
 
It looks like there's more going on though as sprites / characters are flipped vertically. Most likely a bad XOR gate ('86), multiplexer ('157) or a bad attribute RAM..

-Y
 
ill know more tomorrow when i go check out. but sounds like monitor came from a mirror unit. he didnt say distorted or anything, just backwards.ill check the ohms. oh and i didnt mean cut wires just cut plastic in middle of 4 prongs basically creating 2 plugs. thanks much. ill keep ya posted.

If the monitor is mounted so that the chassis is on the left side of the cab when facing the back, then the monitor was installed upside down. The chassis should be to the right (opposite side from the game PCB) when facing the back...
 
Yeah- it's not a monitor problem or anything with the yoke wires.

Something is whacky on the board.

unless you're the one selling it, or have seen it, we don't know that for sure. The pics in this thread were from somebody else who mentioned a problem they had that could relate to the description given...
 
unless you're the one selling it, or have seen it, we don't know that for sure. The pics in this thread were from somebody else who mentioned a problem they had that could relate to the description given...

The characters are flipped individually... It's on the board and it's affecting tile-mirroring.

-Y
 
The characters are flipped individually... It's on the board and it's affecting tile-mirroring.

-Y

Well, I haven't seen a picture of the game in question, so I wouldn't know. The description given from the OP does not indicate that either...
 
unless you're the one selling it, or have seen it, we don't know that for sure. The pics in this thread were from somebody else who mentioned a problem they had that could relate to the description given...

Ahh- got it. Phet was just offering assistance by describing an issue with HIS board. So, you're right. Based on the original poster's information, it could just be a mirrored image.

Phet- quit helping. You're making me look foolish..
 
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