rvIceBreaker

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Hey all,

Friend of mine bought a cabinet for Lethal Enforcers, and being a light-gun game we want to get the CRT running.

We've already swapped the Flyback since the original popped a hole through its housing, and we've installed a cap kit in it.

We can get picture from it, however its suffering from a strange issue that we can't seem to find any information on.

The picture is offset halfway off the left side of the screen and loops around to the right side of the screen. On top of that, its jittery as all hell.

The horizontal positioning jumpers had no effect on the position of the image.

I have other WG/Zenith boards I can pull parts from (unsure of their actual health), and I've swapped IC2 (LA7823) thinking it might be related, as well as C18 and C19 since they seemed to react to thermal changes (spraying with air duster to cool it).

What we haven't done yet is replace the pots (VRxx), voltage regulator (IC4), HOT (Q11) or H Drive (Q10).

I also don't have a multimeter I'd necessarily trust in a higher voltage circuit so we haven't probed for voltages at all, not to mention we're a bit leery of sticking our hands into a running CRT.

Another strange problem is that whenever the V and H syncs start to become in-line with each other, the picture will drop out and it fades to black. The only way to get the signal to come back again is to force it out of H Sync, then re-sync it back to its offset position.

Does anyone have an idea of what could be the most likely culprit? We're stumped for ideas.

Here is a video of the issue we're having
 
is your sync on pin10 only?? did you reflow solder on all header pins and higher wattage resistors and any other suspect areas?
 
is your sync on pin10 only?? did you reflow solder on all header pins and higher wattage resistors and any other suspect areas?

Not sure what you're asking, pin10 of what? Sorry we're a little new to this...

We didn't reflow the header pins, mainly because they look fine. The board is in considerably good shape as far as cold joints and overall cleanliness.

I was going to reflow them last night as a last resort, but we decided to call it instead, so as it stands those remain untouched so far.

We did go through and re-solder R98 through R101 (which i believe was a recommendation somewhere on here), even though most of those looked perfectly fine as well, save for R100 which looked a little burnt.
 
the header pins are never fine. if you're new to this you probably won't be able to identify the breaks in the solder very well yet. it's something you learn from experience. :p

you probably picked up on my suggestion about the resistors. skipping that step can net you a dead chassis afterwards.

the adjustment pots break if you blow on them. you'll have to master how to identify the breaks in those too. :) if anything I would guess probably the H. Pos pot. the K7000 remote boards are notorious for breaking.
 
the header pins are never fine. if you're new to this you probably won't be able to identify the breaks in the solder very well yet. it's something you learn from experience. :p

you probably picked up on my suggestion about the resistors. skipping that step can net you a dead chassis afterwards.

the adjustment pots break if you blow on them. you'll have to master how to identify the breaks in those too. :) if anything I would guess probably the H. Pos pot. the K7000 remote boards are notorious for breaking.

I'll give the headers a reflow tonight to be on the safe side.

Respectfully, its not electronics I'm new to, its CRTs that I'm new to.

The solder is looking chalky (as most lead-free stuff does) but there aren't any cold joints that I've noticed so far. However I haven't fine-tooth-combed the board yet, so its certainly still a possibility, so I'll give that some attention tonight.

I have to wonder if someone got to reflowing some of the components before we did, since its in pretty good looking shape for being manufactured when I was born haha.

The pots are definitely a suspect on our list since they aren't very responsive to the touch, but since the picture is as coherent as it is I wouldn't think that would be entirely to blame, but its definitely next on our to-do list.

If it were pots I would imagine we just wouldn't be able to calibrate H or V holds very well, would that really cause it to jitter the way it does?
 
is your sync on pin10 only?? did you reflow solder on all header pins and higher wattage resistors and any other suspect areas?

To properly answer your question Security, we're syncing on Pin5 I believe. The jamma board only has a 6 pin connector for video output.
 
I'll give the headers a reflow tonight to be on the safe side.

Respectfully, its not electronics I'm new to, its CRTs that I'm new to.

The solder is looking chalky (as most lead-free stuff does) but there aren't any cold joints that I've noticed so far. However I haven't fine-tooth-combed the board yet, so its certainly still a possibility, so I'll give that some attention tonight.

I have to wonder if someone got to reflowing some of the components before we did, since its in pretty good looking shape for being manufactured when I was born haha.

The pots are definitely a suspect on our list since they aren't very responsive to the touch, but since the picture is as coherent as it is I wouldn't think that would be entirely to blame, but its definitely next on our to-do list.

If it were pots I would imagine we just wouldn't be able to calibrate H or V holds very well, would that really cause it to jitter the way it does?


most monitors are NOT lead-free solder. 63/37 with lead will get you the best soldering results on the old crts.
 
post a picture of the header/wire connector.

I don't have physical access to the cabinet at the moment, I'll post one when i get the chance.

From memory, its wired R-G-B-Gnd-Snc though. The game's manual doesn't specify what kind of sync its using, so using +VSync was kind of a guess, as opposed to using +HSync.
 
I don't have physical access to the cabinet at the moment, I'll post one when i get the chance.

From memory, its wired R-G-B-Gnd-Snc though. The game's manual doesn't specify what kind of sync its using, so using +VSync was kind of a guess, as opposed to using +HSync.

the 10pin input header on a K7000 needs sync on the last pin (pin10 only) and if you have a 6pin connector you don't have sync in the correct location on the monitor which would explain your problem.
 
the 10pin input header on a K7000 needs sync on the last pin (pin10 only) and if you have a 6pin connector you don't have sync in the correct location on the monitor which would explain your problem.

Son-of-a.... That did it. That connector must be some after-market thing.

I never thought to check sync pin, because we had video already. Good waste of a week on that one...

Apparently the owner of the cab bought our replacement flyback off you, huge thanks from both of us!

And thanks for the responses from everyone. Still some issues to sort out, but its looking good so far.
 
Son-of-a.... That did it. That connector must be some after-market thing.

I never thought to check sync pin, because we had video already. Good waste of a week on that one...

Apparently the owner of the cab bought our replacement flyback off you, huge thanks from both of us!

And thanks for the responses from everyone. Still some issues to sort out, but its looking good so far.


glad to hear i could help point you in the right direction.
 
Just pulled a picture that I had uploaded to KLOVIMG a while back, of a K7191 I was working on, and lo and behold, I captured the input header in the pic.

It is on the right side, just north of the screw that is securing the chassis to the spacer on the metal frame.

It is a "10-pin" continuous header, but is actually labelled as 2 connectors - P1 and P2.

The pin closest to the screw is pin 1. The pin closest to the tube is pin 10.

You want RGB and video ground landed appropriately on pins 1-6. Sync will go on pin 10 (closest to the tube). There is no pin in the #7 position.

Hope this helps. If you see something different on your chassis, post a pic.

:edit: ugh, I missed this entire second page of the thread. Sounds like you've resolved it, so this info is probably too little too late. Congrats on the fix!

 
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