G07 shifted to the left 1+"

richpuch

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Donor 2023-2024
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I've stepped into monitor chassis repair and picked up 4 G07 that all were shipped as 'consider non-working'. I've done a bunch of video watching and thread reading and carefully worked on these chassis. The first three, I got working with great results however the fourth one is giving me a battle. I'm glad this one wasn't the first one I did, otherwise I would have thrown in the towel on chassis repair.

Anyways, here is what I 've done:

washed in water to remove ages of dirt and dust
visual inspection, 901 fuse was blown
flyback looked good with no cracks, some goop on top, no mounting posts to the chassis as these flybacks normally have on G07s, looks like a knock off, may not be for G07
width coil was broken
everything tested ok on the power side with meter as per Amateur Mike's videos
first try powering up the tube and I thought I heard high voltage, but nothing on screen
powered off, went to discharge tube and it had no static sound
filter cap was charged up, when shorting I got a big spark and blew fuse
did a recap with a kit from www.arcadepartsandrepair.com along with filter cap
did a lightbulb test and voltage was high, moving B+ POT made no difference
after some KLOV research resistor 908 is NG, had to test out of circuit
replaced 908 and did light bulb test and was able to control voltage...voltage only went up to 117 with POT turned all the way .
Replace R517 because it was out of spec, reading 220 K ohms instead of 180 Kohms
Tested B+ pot out of circuit, it wouldn't go below 227 Ohms.
Replaced B+ pot, and voltage was adjustable to 120...
Replaced flyback and chassis worked...image not centered.
Picture stable, but statically shifted left following flowchart shifting image shows x301 and x305 (I assume that means image is moving to the left mine was just statically shifted, but investigated the X301 and X305)..
Checked both X301 and x305 and initially x305 seems bad...ordered 2SC1815 from Digikey
Replace R516 because it was out of spec, reading 0 ohms instead of 180 Kohms (could cause image darkness)
Replace R512 because it was out of spec, reading 7.3K ohms instead of 8.3K Kohms
Received new replacements and checked X301 and X305, pulled them both and compered to news ones and they tested fine.
pulled IC501 and socketed and new IC501 and still same problem (screen shifted to left about 1"+)
I tried to move image with the jumper on the G07 board and it wouldn't move, even if I moved it to each jumper post
I added the Image centering mode from www.arcadepartsandrepair.com and still very little image movement, not enough to make it a useable chassis
Replaced all 4 pots on board because they were all very touchy, slightest movement created havoc on the screen
went ahead and replaced X301 and X305 because I was out of ideas.
replaced X304
tested X303 out of circuit with a new one and it was identical

I'm stumped, any ideas. Is it possible a bad cap from the kit? I didn't change C402....however that is for a vertical collapse which is not what I'm seeing.

I even stuck GoldenTee 2K on this chassis monitor and get the same image, if I try my other 3 G07 I get a nice centered image on this tube and yoke.

Thanks for any recommendations.
 

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You replaced a lot of stuff that had nothing to do with your problem. R516 is 150k ohms, not 180k. (it may be within tolerance and probably isn't the issue, but who knows)

DId you adjust the H-freq pot? It should shift your image, then if you have curl you either have to live with it, or go from there.

Additionally, I typically don't trust the TPG to center the image perfectly. (edit, I see you tried it in a game).

start with the h-freq pot.
 
May as well add...............show us a top and bottom pic of your chassis when you get a moment.
 
Thanks for response....

Yeah I tried the H-freq pot with no luck....If I move the pot ever so slightly in either direction I loose that image on it goes crazy. I remember reading the TPG is sometime flaky on certain chassis, I've tried it with an actual pcb (Golden Tee 2K) and it gave same non-centered image. I've got a few other boards I can try.
 

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Your chassis looks pretty good. Because you had success with the prior 3, I doubt anything weird was done. I'd start beeping out traces, looking for a broken trace.

Maybe start at the flyback and work outward. Then go do the monitor input , 3 pin and 6 pin headers and working outward. (put a 150k ohm resistor in R516, but I'm not sure that is really a problem).
 
Did you change R414 (3.3k ohm resistor) as well? I didn't see you indicate that you changed it, but it looks new.

Also just for clarification, you said you bought parts from ArcadeRepairShops. Do you mean www.arcadepartsandrepair.com?
 
Your chassis looks pretty good. Because you had success with the prior 3, I doubt anything weird was done. I'd start beeping out traces, looking for a broken trace.

Maybe start at the flyback and work outward. Then go do the monitor input , 3 pin and 6 pin headers and working outward. (put a 150k ohm resistor in R516, but I'm not sure that is really a problem).
Yes I did change R414, and I don't remember if it was out of spec or not....it must have been. I forgot to add that in my personal log, will add it.

Yes i did mean www.arcadepartsandrepair.com?....good catch I will correct, to give them credit for their cap kits.

I'll start tracing things out...thanks for your input. I write back if I find anything.
 
Would changing the width coil cap help with this?
I thought about the width cap. But wouldn't that just shrink or enlarge the image width wise? I also tried adjusting with width coil and that didn't do much either.
My problem is I can't seem to move it over to the right.
 
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