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Author Topic: G07 vertical roll  (Read 2627 times)
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Shun_di
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« on: July 08, 2016, 05:17:12 pm »

Hi,

I was wondering if anyone can help me here.
I have an Electrohome G07 monitor (CBO chassis) in a Pole Position cab.
Its hooked up to a recently serviced Namco Pole Position board however the picture rolls vertically and will not lock however much I adjust the v hold pot. I've tried the following fixes on the chassis and I still can't stop the image rolling:

Sync header solder removed and re-added
X302 and X306 transistors (2sc1685) replaced (existing appeared to be good anyway)
IC501 (HA11244) socketed and replaced
V hold pot removed, tested and re-soldered
B+ adjusted to 120V

I've also hooked up the board to a RGB start tv and the picture is fine on that so the issue is definitely with the monitor.
Does anyone have any other ideas of what I can try?
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mrdude
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« Reply #1 on: July 12, 2016, 10:21:20 pm »

I encountered something similar to this the other day. No matter how I turned the Vertical Hold pot it wouldn't lock in. It would roll one way or the other. Turns out one of the sync wires going to the monitor was loose and didn't have a good connection. Probably not your case, but thought I'd mention it. Did you try the monitor with another harness or game? I know you said the board is fine, but let's rule out the middle man (harness).

Good luck!
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Shun_di
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« Reply #2 on: July 17, 2016, 07:15:25 pm »

Thanks for the reply. Do you have a youtube channel called "That Tim Guy"? If so, I'm subscribed to the channel, the videos are great.
Anyway, regarding the harness, the way that I tested the board on a RGB scart TV was to use some small solid core wire connected to the scart cable and plugged directly into the wiring harness connector which in turn is connected to the board. So the harness is good as well.

So, I'm out of options. Well almost. I've sent the chassis off over to someone here in the UK who's pretty good with monitors and he should hopefully be able to fix it for a reasonable price.

I'll post a few videos ups on my channel soon once I get around to editing stuff. I also have a load of footage for the Pac-Man build. I think the Pole Position has been distracting me  Grin
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BadMonkey
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« Reply #3 on: July 19, 2016, 05:42:53 pm »

Shot gunning the g07 could have fixed your issue. TherealBobRoberts.net sells a deluxe kit for the g07 which includes the caps, HOT, soldered fuses, fly back, and power transistors. Re -flowing all your pins and your sinc connections is always good practice. I have done a few g07's and just did my centipede the other day. The deluxe kit is the way to go.
« Last Edit: July 19, 2016, 05:44:32 pm by Jofis » Logged

just rebuilt another g07. On to the vector on Asteroids!
Shun_di
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« Reply #4 on: July 23, 2016, 05:41:22 pm »

Shot gunning the g07 could have fixed your issue. TherealBobRoberts.net sells a deluxe kit for the g07 which includes the caps, HOT, soldered fuses, fly back, and power transistors. Re -flowing all your pins and your sinc connections is always good practice. I have done a few g07's and just did my centipede the other day. The deluxe kit is the way to go.

To be honest, I'd pretty much given up on fixing the issue so caved in and sent it off for repair to one of the guys over on UKVAC.
He's now fixed it for me and said that one of the resistors in the sync circuit was open. He's also replaced all of the caps and cleaned the chassis which was filthy. So he's pretty much serviced the chassis and for a very reasonable price too. i'm looking forward to getting it back and into the Pole Position.
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