Choplifter Sync issues jamma harness

brocksampson

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Not sure if this is the right section but here goes. I'm rewiring my choplifter cab with k7000 monitor with a new twisted quarter jamma harness. I made a jamma adapter and tested it on my bench no problems. I'm having problems with getting the picture to sync. I have tried all variations of sync wires. Both tied together, just -v, just -h. I have put a new end on the sync cable and new end on the ground cable still no dice. Just to verify I didn't screw up the adapter I put my test harness in and it syncs great. I traced the wires and all look to be in the correct location on the harness. My test harness only has -v sync. Attached are pics of the image with new and test harnesses as well as pinouts of each connector. I don't understand why it won't sync with the new harness. Any help would be appreciated.
 

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your black wire i am guessing should be your video ground and should be in the 4th position of the connector next to the blue wire. and your white sync wire stays on position 10.

FYI: the reason your test rig is working is you have a 6 position and a 3 position header and both those headers i am betting have a video ground so you only need to be connected to either one of them since they are bridged/attached together on the pcb while your k7000 has a 10pin header and only 4 is your video ground.
 
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Switched ground to pin 4 still no dice. That test harness is a 10 position just split at 7. Attached is a pic of the original choplifter harness. I stole the connector and originally wired it to match but that didn't work either. I think I'm going to pull that new harness and test continuity on the ground and sync pins.
 

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Switched ground to pin 4 still no dice. That test harness is a 10 position just split at 7. Attached is a pic of the original choplifter harness. I stole the connector and originally wired it to match but that didn't work either. I think I'm going to pull that new harness and test continuity on the ground and sync pins.

you didn't take the sync off pins 9 and 10 in your picture which it can only be on 10 for a k7000.
 
The last pic was the original harness that I took out that had pins 9 and 10 tied together. I originally jumped 9 and 10 together on the new harness but didn't take any pics like that. After I tried my test harness and got sync with just 10 I switched my new harness to match. So I have tried ground at pin 4 and 8 still same. Tried sync at 9 and 10 still same. Tried sync at 6 and picture was worse.
 
So I took the jamma harness loose. I'm getting good connection on all of the video connectors with my meter. They are all pinned to the correct locations on the jamma connector and match my test harness. So I'm really confused I don't get why this new harness isn't working.
 
You don't mention it, but I'm guessing you've already tried playing with the H.HOLD & V.HOLD pots on the chassis.
 
I think there most be something flaky in the jamma adapter I made. I had to put the basement back together for my son's birthday party tomorrow but before I put everything away I plugged in my speed rumbler pcb into the new harness great picture no issues. I'm going try to fiddle with that adapter post sleepover if I can't get it I'm ordering one of these which I probably should have in the first place.

http://arcadeforge.net/Jamma-Adapte....html?MODsid=bf9680ed95b2f00b866775021ea0b73a
 
Got new adapter from arcadeforge today and synced right up I must have had something wonky in that adapter I built, which has been terminated with extreme prejudice.
 
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