Help me save this g07!

Ghostnuke

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Cause I'm going to punt it over my garage if you dont.

I've replaced flyback, hot, vr, caps, width coil, fuses, ic501, x301, x302, x305, x306, reflowed all header pins and still can't get the damn thing to work. The tube and yoke are both good. I'm testing with a Galaga board. The starfield shows up correctly, but the words are all messed up like it's not syncing correctly.

I was poking around and was adjusting the width coil when something underneath it sparked and now there's no picture at all. /facepalm
I decided to call it a night before I started hammering it into pieces.

Please give me some advice here.
 
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Post video. Correct starfield, but messed up text kinda sounds like a board issue. I'd like to be sure.

Might be able to get a pic. Assuming I can get it to work at all again. The board is ok I think. At least it works if I try it with another chassis. It is an un-rebuilt Galaga though, so it's possibly fishy. I'll test it again with a working chassis and see what happens.

Any thoughts on the short I mentioned? There isn't even anything under the width coil, how would I get a spark under it?
 
How big was the spark? Could it have been a broken solder joint, and when you moved the coil, it made a better connection, and therefore a spark?
 
I haven't touched it since it shorted out. B+ was spot on and fuses were good beforehand. I'll try to test everything with a known good chassis this weekend.
 
Replaced the small fuse and got this running again with the same problem. Here's a picture this time.

IMG_3268.jpg


Starfield in the background works, but everything else is scrambled. Board works fine with another chassis. B+ is spot on.
 
Replaced the small fuse and got this running again with the same problem. Here's a picture this time.

IMG_3268.jpg


Starfield in the background works, but everything else is scrambled. Board works fine with another chassis. B+ is spot on.

Cant tell from the pics .. if starfield shows up it almost certainly should be a board issue.

If not lately Ive been wrestling with a few go7s with bad trim pots, and sync issues from the header pins. Are you getting trim range with the pots?

Stick with it and stand back, you will figure it out as I am sure its something simple as usual.
 
I am almost positive it's not the board. Right before I took that pic, I had another chassis hooked up to the same tube and board and it worked fine. The pots all seem to be working, as far as I can tell anyway. I reflowed all of the header pins so it should be syncing ok, in theory.

Edit: I've tried wiggling the headers while it's on to see if anything is loose, but there's no change.
 
I just worked on a K7000 yesterday that had what looked like game board issues. It turned out the Hot was shorting to the chassis intermittently. Might be worth a check.

I am almost positive it's not the board. Right before I took that pic, I had another chassis hooked up to the same tube and board and it worked fine. The pots all seem to be working, as far as I can tell anyway. I reflowed all of the header pins so it should be syncing ok, in theory.

Edit: I've tried wiggling the headers while it's on to see if anything is loose, but there's no change.
 
That looks like a hoizontal synch problem. Does the monitor make a crazy high pitched sound? Look at the schematic, and check any semiconductors in the h synch circuit. When you adjust the h synch pot, does the screen/sound change?
 
That looks like a hoizontal synch problem. Does the monitor make a crazy high pitched sound? Look at the schematic, and check any semiconductors in the h synch circuit. When you adjust the h synch pot, does the screen/sound change?

I originally thought so too, so I replaced X301, X305 and IC501. There was no change though. There is one pot that makes a horrible screaming noise if I turn it as well. It's the one farthest to the left of the chassis if you're looking at the tube side of the monitor.
 
shoot- you're almost there-

vertical deflection - check
horizontal - check
HV- check
brightness/contrast/color - check check check

Get your knubby fingers in there and adjust that horizontal frequency into range.

You've got picture data there, son. It's just not lining up like it should.
I think the horizontal frequency is off far enough that it can't sync up.
 
Well, the H oscillator must be running or you wouldn't get any scanlines-

Do you have a scope?
Are you sure the sync signals are getting to the IC501?

Scope out pin 16 there.

Does the HFreq pot do ANYTHING?

Your comment about the starfield is pretty confusing. Do you see a starfield in that picture you posted? I can't see a starfield.

Does anything happen if you hook the sync pins up to the other inputs? (positive vs negative).
 
I just had this issue yesterday. Recapped, new flyback, proper sync wiring - no sync. Checked to make sure the two resistors were the 390-ohm resistors instead of the 4.7k-ohm that were mistakenly put on some G07's. Then I saw my dumb mistake. I had done the curl mod by removing C501 and moving C303 to the C501 spot, but I forgot to put the 10uf 50v cap in the C303 spot....
 
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