Repairing SI Monitor: On bench vs. in-cabinet? (WG19v1001)

Mojodog333

Active member

Donor 2024-2025
Joined
Nov 5, 2024
Messages
379
Reaction score
157
Location
Michigan
I just finished bringing back an SI board that I took from a trashed cabinet and starting on the monitor. I will be putting this board and monitor in an empty cab I found in decent shape for $75. (Franken-vaders?) I have been working with things out on my bench but not sure this is really feasible with the monitor since it is not integrated into the chassis like the other ones I've worked on. I plan on doing as much as I can before reconnecting everything (ring out bottlecaps/BRs, measure ESR, go over the solder joints, etc.)

After that, any advice on the best way to work on this? Working on it in the cabinet doesn't look like fun. I could build some sort of rig to mount the tube in an orientation that keeps the neck safe but allows me reasonable access to the board, but wasn't sure if there was an easier way to approach this. Is there a safe way to power up the chassis without the tube to go through checking the voltages and circuits behavior relative to the service manual. (I suspect it is something in the vertical section as it was a flat horizontal line before I tore things apart) I could tape up the leads that go to the yoke, but was not sure about the flyback, or anything else that might make me regret not sucking it up and digging around in the cabinet to work on it.

Thanks!

-John
 
the V1001 has the isolation transformer built into it, so you could do just that except the tube is separate from the chassis part, so I would encourage doing it in the game.

Thanks, I hadn't considered the transformer because I was going to power everything from the main transformer and power supply using the game's harness. But if you are saying it's bad to power up a chassis without a tube connected, I'll start reassembling everything in the cabinet. Just wanted to confirm there wasn't a better way to approach it. Sea Wolf wasn't too bad because the chassis hangs vertical facing the back of the cabinet. SI sits on a shelf directly under the tube.
 
Thanks, I hadn't considered the transformer because I was going to power everything from the main transformer and power supply using the game's harness. But if you are saying it's bad to power up a chassis without a tube connected, I'll start reassembling everything in the cabinet. Just wanted to confirm there wasn't a better way to approach it. Sea Wolf wasn't too bad because the chassis hangs vertical facing the back of the cabinet. SI sits on a shelf directly under the tube.
I didn't say power it up without the tube connected I said to do it in the game. also don't hook the yoke wires up wrong. there's colored dots on the yoke assembly indicating what wire goes where but that's for standard orientation, not mirrored. I think red and black are the horizontal pair and like green and grey are vertical pair. I don't remember the wire colors off hand now.
 
Measure the yoke windings to confirm which pair is which. I just finished repairing a SI monitor where someone had temporarily mixed up the yoke wires. Luckily it was repairable. They had also removed the yoke so that had to be reinstalled too. Got it rebuilt and have it working.

I just ordered a pair of brackets that were on the normal 19V1001 so I can use those in the future for holding a SI monitor together while working on them.
 
I didn't say power it up without the tube connected I said to do it in the game.

Thx, I see that now. Jet lag's a bitch...

I did mark the yoke wire connections with a sharpie before removing them, but to @RobotWorkshop 's point, they may not have been correct to begin with. When I was running the test ROM, I found one of the buttons had the logic ground connected to the ground plate under the switch assembly ground of the transformer connected to the switch contact. How do you F that up? It's not like its a blade terminal that got knocked off and got reversed by someone just randomly plugging together things that fit. It's a soldered connection.
 
You want a monitor extension cable, to be able to run the monitor outside of the cabinet, but still be connected to the cabinet.

In this case, it's the same as an extension cable for b/w vectors. 12-pin Molex.

@Jason_971 used to make and sell them here, not sure if he still does. I've seen them on ebay as well. Or you can get the parts and a crimper (both of which you should have anyway, if you're in this hobby) and make one as long as you want. I have ones for 12-pin (b/w) and 15-pin (color vectors), that are 10 feet long each, and they come in very handy.

Here's a thread with more info:

 
You want a monitor extension cable, to be able to run the monitor outside of the cabinet, but still be connected to the cabinet.

In this case, it's the same as an extension cable for b/w vectors. 12-pin Molex.

@Jason_971 used to make and sell them here, not sure if he still does. I've seen them on ebay as well. Or you can get the parts and a crimper (both of which you should have anyway, if you're in this hobby) and make one as long as you want. I have ones for 12-pin (b/w) and 15-pin (color vectors), that are 10 feet long each, and they come in very handy.

Here's a thread with more info:


Thx! I have almost everything to make an extension, but at least in this case, i dont necessarily need one because the transformer, PS, and harness are laid out on my bench. I used this setup to test out the PS and fix the game board. The problem is the monitor is just awkward to work with outside of the cabinet. Right now its face down on a blanket. The connections from the chassis are too short to connect in that orientation. I either need to build some sort of rack for it or just suck it up and work on it inside the cabinet as mecha suggested.
 
If it's a 19" tube, you could mount it in any 19" monitor frame, if just holding the tube is the problem.

I had the same issue with Amplifone vector monitors (which don't have a frame, in Star Wars cabinets. The bare tube is bolted to the cab, and the deflection and HV boards are bolted to the sides of the cab). I just mounted the tube in a spare G05-802 frame I had laying around.
 
I made my own extension cable for working on the Black and White composite monitors. If you make one I would highly recommend using a M/M RCA extension cable and a F/F RCA adapter. Then cut the RCA cable in half and use the F/F to join the cable. Put the cut ends into each connector.

With that you can plug it in any cabinet and easily test output from the game board (by connecting an external flat panel with composite input) and test the monitor in game by connecting any composite video source. Or just use it as a regular extension cable. I've found splitting the video portion with that RCA cable really helps!
 
Space Invaders is unusual because the chassis sits below the tube which is oriented up. So yes, work it in the cab, or in a place where you have a tube and can attach the ground and anode to the tube.
 
Last edited:
I made my own extension cable for working on the Black and White composite monitors. If you make one I would highly recommend using a M/M RCA extension cable and a F/F RCA adapter. Then cut the RCA cable in half and use the F/F to join the cable. Put the cut ends into each connector.

With that you can plug it in any cabinet and easily test output from the game board (by connecting an external flat panel with composite input) and test the monitor in game by connecting any composite video source. Or just use it as a regular extension cable. I've found splitting the video portion with that RCA cable really helps!

That's a neat idea!
 
I was able to bring it up on my bench and the image looked good, but when I installed everything in the cabinet, I am getting what I would call vertical jitter. (Is there a name for this?)

1751905342159.png



I am trying to figure out how moving it would have introduced this. I know there are some pots on the board in the vertical output section. Maybe one of them needs to be cleaned? I guess it could be a solder joint as well, but I thought I went over them pretty well.
 
Looks like noise, possibly leaking into the power supply from somewhere.

Try unplugging all fluorescent lights and other non-critical stuff inside the cab, to rule those things in or out.
 
Hmmm. There is nothing plugged in that was not on my bench. I have not even connected the black light or marquee. Pretty much, PS, Main board, and monitor.

I'll double check none of the free hanging wires got knocked loose from any of the caps on the chassis and look if there is some ground that isnt connected somewhere in the cabinet. Also go back and check all the rails for noise or ripple at the supply, then just drill down into the blocks of the circuit looking for some signature that might explain what I am seeing. The good thing is that it is persistent. I'm not chasing some randomly occurring bitch of a problem.
 
Agreed that it looks like power supply noise.

Check the CRT anode connection. It might be loose and arcing, causing that type of spiky noise.
 
I powered it up this morning before work and the issue was not there. Let it run an hour or so and it did not come back. I'll play with it some more tonight. I'm hoping I can get this up for sale soon so I can start on an Out Run project I'm picking up tomorrow.
 
Back
Top Bottom