G07 -- any point to trying to adjust out curl w/no game board attached?

hindered

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G07 -- any point to trying to adjust out curl w/no game board attached?

I just did a cap kit, HOT and flyback on a G07 I had that was displaying some pretty serious foldover/curl. I also replaced the pots. There were some hacks done to this board on the solder side, 3 diodes and a cap were bridging some of the traces. I undid all of these hacks as part of the cap kit. I also did the C303/C501 mod as recommended by Bob Roberts.

Hooked the monitor up to my ISO (which is on a test bench but has no harness hooked up to it yet -- it's just 120vac -> ISO -> monitor) and turned up the screen control until I could see white raster -- success! However, there's still a bit of curl. I checked the B+ and it's at like 119.8 -- close enough for jazz. I tweaked the other pots but couldn't get rid of the tiny bit of curl at the top.

A: Is there any point in me trying to adjust out the curl w/o any board attached? Is the white box/raster enough?

B: Bob's notes say to adjust B+ until there's no curl. Does this mean to forget trying to get it as close to 120vdc as possible and just look at the curl, tweaking it until the curl is gone?
 
If you have to crank it to 100 or 140 to get it out, then leave it alone. But 118 or 122 isn't going to kill anything.

Also, you'd better put those "hacks" back on. Those are undocumented factory modifications to correct minor issues during final testing. They need to be there. Some are probably in the schematics, but were mounted to the bottom because there wasn't any room on the top. They might even be contributing to your current problem AFTER the cap kit which should have fixed it...
 
If you have to crank it to 100 or 140 to get it out, then leave it alone. But 118 or 122 isn't going to kill anything.

Also, you'd better put those "hacks" back on. Those are undocumented factory modifications to correct minor issues during final testing. They need to be there. Some are probably in the schematics, but were mounted to the bottom because there wasn't any room on the top. They might even be contributing to your current problem AFTER the cap kit which should have fixed it...

You know, I thought about checking to see if those were supposed to be there or not, but I had a couple sanyo chassis that had resistors soldered to the solder side and they always came off, sooooo. I just assumed they needed to go. :) Thanks, I'll put them back and try again.

EDIT: Good thread about it here: http://forum.arcadecontrols.com/index.php?topic=45704.0 I'll check those resistors too.
 
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Put the diodes & cap back in, and checked all resistors mentioned in the other thread were the right values. No visible change to the monitor. I'll just wait until I have a game board hooked up to it to continue futzing with it.
 
The answer to the question, at least in my case, is "no, there is no point to trying to adjust a monitor w/no board attached".

Here's pics of it w/a semi-working gt2k attached. Ignore the bars, they're from the PCB. Looks pretty decent IMO, although I hope the 60 in 1 doesn't need much adjustment, this cab is a BITCH to get to the adjustment pots when the monitor's in the cab... Maybe I'll just order the board and leave everything out until it arrives and do the adjustments out of the cab and THEN button it all together...

Also pics of my ghetto jamma monitor test harness I threw together today for this purpose and my small test bench.. I hope to get another table down in the workshop tomorrow so I can leave stuff like this set up permanently on it while I still have my workbench for soldering/etc..
 

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I am going to revive this post, because I am experiencing a similar issue.

I have not checked the b+ yet. Start there huh?

virtually the same rebuild as mentioned by the OP. new everything, only I did not removed any "factory hacks"
 
Here's a tip for you: You can adjust your GO7 till you're blue in the face and you will most likely never get rid of the curl it's gonna produce on the right side of the monitor with your 60 in 1 board. These boards do not work well with the GO7 period and it's not the fault of the monitor. Cranking the B+ well beyond the factory specs is going to lead you down the path of several other part failures.
 
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I put it in my tron.

and the picture never looked so beautiful. way better than the k4900 I had in there. (which I just recapped)

I will try to adjust it a bit more. It doesn't really bother me, but I was hoping after the modification that bob suggested and rebuilding this bitch it would be perfect.
it is close though


i should mention, the only thing I did not do to this chassis, is replace the resistor r908 I think.
I couldn't find it, lol, so I didn't change it. still could if anyone thinks that it matters.
 
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Here's a tip for you: You can adjust your GO7 till you're blue in the face and you will most likely never get rid of the curl it's gonna produce on the right side of the monitor with your 60 in 1 board. These boards do not work well with the GO7 period and it's not the fault of the monitor. Cranking the B+ well beyond the factory specs is going to lead you down the path of several other part failures.

I should mention that I have had some G07's work just fine with the 60-in-1 with no curl, and others that have been pretty bad.

Now, is this caused by some mystery part on the G07 that is slightly out of tolerance on some chassis' but not on others? Or is there some difference in the manufacture of the 60-in-1 or it's programming between different versions? No clue, although I'm leaning towards the 60-in-1.

Of more significance is that some of these 60-in-1's lately have produced a severely shifted image using the RGB output (as opposed to the VGA). This has been reported on several different monitor models, not just the G07...
 
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