G07-FBO Partial Horizonal Collapse

Peale

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This is an odd one.

Took in a repair, as noted in the subject. Recapped, replaced flyback (original had a crack). Powered it up to find partial horizontal collapse. Yes, I have it correct. I'll attach a photo later.

Lots of solder touched up, B+ @ 117VDC steady (and, obviously can't be adjusted, nor do I think it's part of the problem).
 
Okay, I had thought that it was collapse, but now I'm reevaluating that statement - I believe it to be foldover.

Photos forthcoming - batteries in the camera are dead.
 
I'm starting to wonder if this might be flyback related. The existing flyback had a crack, so I swapped it with one for a CBO.

Where on the chassis can you meter for specific voltages, related to flyback output, and what voltages those pins are supposed to supply?
 
Most definitely appears to be the flyback. Replaced the CBO model with the original (and ducked in case it exploded or started to throw sparks) and....nothing. B+ is now metering @ 134VDC. It appears to be in shutdown.

I'm at a loss of what to do here...there are no FBO flyback models available, and the CBO one, though I got it to work, made the picture horribly shrunken. What I thought, at first, was collapse, isn't. It appears to be as Modesitt described in a few other threads.
 
I'm thinking that I might want to experiment with the values of C517 and C518. I had originally put in the CBO values in these spots (220 and 100) but when I saw that I had issues, I swapped out the 100 with a 47.

Will these affect the overall picture, or just in one direction? I did note a change when I moved from the 100 to the 47, but how much change was the question. Should I go with 100/47, or even 47/47?
 
Replaced the fly with the CBO model, B+ still @ 140VDC.

Replaced the VR...STILL @ 140VDC.

At first I thought it might have something to do with IC501 (I'd pulled it before to swap it out when I originally started having issues, but socketed/replaced once I realized what was going on). I fired it up once with it missing. That /shouldn't/ have done anything...right?
 
Just curious.....did you install a complete CBO cap kit in the FBO chassis? There's quite a few caps that are different between the two.

Edward
 
I made the changes when there were differences. I didn't replace the 1uf @ 50V BP because I can't find the bag that I bought. Other than that, they've all been replaced.
 
This thing is kicking my butt. Using notes from another tech that I posted in the G07 Common Issues thread

http://forums.arcade-museum.com/showthread.php?t=196257

I've been metering voltages.

I've got 140 VDC on the collector of X501, but nearly nothing coming off the base or emitter.

IC501 is supposed to have 12VDC on pin 11, but I'm only getting 8VDC.

I've replaced both IC501 and X501.

I can not find any evident cracks. All the traces are Ohming out just fine.

Suggestions?
 
Shrunken picture with a CBO flyback, so I swapped back in the FBO flyback, and...back to 140 VDC, For the first ten seconds though, the B+ was @ 117 VDC, then cranked up to 140. And, now it won't come back down.

There's got to be a way to get a CBO fly to work with one of these cranky FBO chassis.
 
Just making sure that it was, indeed, the flyback, I put the CBO one back in, and it fired right up.

I'm going to include a photo in a moment. Modesitt, I'd like to hear from you to see if that's what you also get when you have one of these "problem child" chassis.
 
I was going to experiment with C515, taking another from a parts chassis and doubling it. I'd been letting the chassis run, and when I disconnected it, the HOT is...well, hot. Really hot. Is this going to be an issue? It wasn't hot enough to burn me, but it was pretty close.
 
Figured "heck with it" and did it anyway. Picture may have changed by doubling the caps, but it's very, very subtle.
 
I had the bright idea to pull the flyback from my own working FBO chassis, installed it...and, the problem persists. I couldn't believe it. At least the CBO flyback works on my chassis (though the image /is/ a little small, but only a little).

Any suggestions? This has me really stuck. See the above screenshot.
 
Son of a gun. I fixed it.

Remember how I remarked that the HOT was getting....well, hot? Like, really hot? I thought, perhaps, that maybe it was leaky. Or, being overdriven somehow. So, I thought that I'd replace it.

So, as I was removing it, I noted that one of the legs was bent. Like, /really/ bent. It was bent so that it wouldn't touch the frame.

Because the darn thing was installed UP SIDE DOWN.

I have no idea how it was operating like that, at all. But, it was. I flipped it around, and now it's working 100%.

Dude. This has had me stumped since I took it in.
 
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