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Sega Astro City - Complete dead monitor?

kazuma

kazuma

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Hi, I'm new here and this is my first post. I acquired an Astro City cab a couple months ago, which is in need of some work on the monitor. The power supply in the cabinet seems to work fine, and the cab did seem to output audio during some earlier testing, but I am unsure where to begin with troubleshooting as I'm completely new to this. I believe the chassis to be a nanao ms9-29 (please correct me if this is wrong). When the cabinet is powered on, the monitor doesn't seem to visibly do anything; no picture, no noise from either the monitor or the board, etc. Here are some pics of the chassis and the rear side of the monitor in general, posting these in case there's something that's immediately and obviously wrong that I haven't noticed. I've been told that the tube itself is fine.

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kazuma said:
I've been told that the tube itself is fine.
Click to expand...
Based on what? Was it tested?

Is the monitor plugged into power?

Can you feel static on the face of the tube if you turn it on?
 
Don't feel anything, get a multimeter and check if there's voltage going into it.
Also: There's two switches to turn on, one on the back, and one inside the front door on the power brick for maintenance.
 
That’s one dirty chassis! Needs lots of love!

I can see that you are missing a capacitor for the power side of the circuit board.
I don’t remember the exact value, but locate the silk screen ID (for example C952) then you can find the values in the link below
https://wiki.arcadeotaku.com/w/Nanao_MS-9_capacitor_listing

PS. Looks like a lot of the cables have been spliced together poorly… I would check everything with a multimeter before firing it up.


IMG_2762.jpeg


Also. Degauss is not connected.

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rewrite said:
Based on what? Was it tested?

Is the monitor plugged into power?

Can you feel static on the face of the tube if you turn it on?
Click to expand...
Currently just going based on the info I was given by the seller. Monitor does seem to be plugged in at the very least, but I actually neglected to check if I can feel any static; definitely will consider this the next time I take a look at it.

Asure said:
Don't feel anything, get a multimeter and check if there's voltage going into it.
Also: There's two switches to turn on, one on the back, and one inside the front door on the power brick for maintenance.
Click to expand...
Is there any components in particular I should be checking if I use a multimeter? Never really used one before, so I don't wanna go poking and prodding blindly. In regards to the switches, both of them are on and the power supply does light up. Plugged in a jamma tester board as well, and it seems to receive power through the connector.

BuddyC said:
That’s one dirty chassis! Needs lots of love!

I can see that you are missing a capacitor for the power side of the circuit board.
I don’t remember the exact value, but locate the silk screen ID (for example C952) then you can find the values in the link below
https://wiki.arcadeotaku.com/w/Nanao_MS-9_capacitor_listing

PS. Looks like a lot of the cables have been spliced together poorly… I would check everything with a multimeter before firing it up.

-

Also. Degauss is not connected.
Click to expand...
Once I make sure the monitor is discharged, I would definitely like to give this thing a deep clean. Are there any non-corrosive cleaning materials you'd recommend for this? Also, there are some cables that were indeed spliced together at some point, the seller informed me of this. Will have to take a closer look once I actually start to further disassemble the cab.


Appreciate the general advice so far, hopefully I should be able to find the time to delve into this further. My one major hurdle that's preventing me from working on this regularly is that the cabinet is currently in storage so I have limited access at the moment. Based on what I've looked at though, I'm sort of considering just re-wiring the whole thing, is this overkill?
 
Cabinet wiring? Don't do a rewire, unless it's really hacked up.

That missing cap will definitely stop the monitor from firing up. However, I would be surprised if that alone fixes your chassis. It looks like a China Special.

EDIT: clarification
 
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Took some more photos after I had some time to check in on it again. Can't really start any work on it since I'm waiting for some tools to arrive, but here's what else I found.
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Control panel is a bit ugly, but the exterior isn't really a huge concern; intending to replace this with a repro based on the original. However, the internals of the control panel are a bit concerning. Based on the diagram from here: (https://wiki.arcadeotaku.com/w/Sega_Astro_City_Wiring_Guide), I seem to be missing the AUX cable. Is that really important for anything?
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Pic from the underside of the chassis board, not sure how concerned I should be about those blackened traces. The tube itself seems to be a Toshiba A68KJU96X.
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A few other curiosities I noticed included this random cap that I found at the bottom of the cabinet, what appears to be some kind of mechanical counter installed beneath the control panel, and an extra chassis controller board: the one pictured in the CP photo from earlier. Turns out it's not even connected, and the actual one is sort of mangled (one of the knobs are busted) and just hanging loose inside of the cab.
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One last thing for now, does anybody happen to know what this says? It's stuck to the bezel above the monitor.
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Yep, that's a China cab alright. I would split it apart, tear absolutely everything out of it and go through everything piece by piece.

C952 (the one missing) is a 220uf 100v cap. They probably had a 250v cap handy but it was physically too large so they tacked it on with wires. FWIW I got my Maximum Tune cabs from the same seller and one of the chassis filter caps was rolling around on the floor of the cab, so these were obviously very poorly handled at some point.
 
kazuma said:
Based on the diagram from here: (https://wiki.arcadeotaku.com/w/Sega_Astro_City_Wiring_Guide), I seem to be missing the AUX cable. Is that really important for anything?
Click to expand...

It's just a pass through cable. You can make a replacement for it or just not have one at all.

kazuma said:
Turns out it's not even connected, and the actual one is sort of mangled (one of the knobs are busted) and just hanging loose inside of the cab.
Click to expand...

The monitor has been replaced. The loose remote is for a MS8-29. Your current monitor is a MS9.
 
Pivoting away from the monitor for a moment to ask for some advice about the main body. For the most part, the cabinet has been completely stripped down at this point. In terms of potentially getting it re-painted, it seems that a lot of people suggest taking it to an auto body shop, so I'll likely go this route. Though I would like to ask if it's alright to use an abrasive tool to scrub off the rust? It's really bad around the doors and hinges.
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Most of the screws came out without any issues; I used an impact drill based on some information I was able to find. However, there's one screw which is proving to be problematic. I accidentally stripped the hell out of it while trying to get it out. I tried using an Engineer PZ-58 for screw removal but I couldn't even get the damn thing to budge. Would appreciate any suggestions, as this is literally the last screw that's preventing me from fully disassembling this bastard.
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The two things I would try would be an impact screwdriver (not drill, the kinda that you use a hammer with, found for cheap in places like Harbor Freight), or the Engineer PZ-60, which are long nose pliers that still has serrated teeth on the tip for grip, but is smaller for better clearance in tight places.

Of course, plenty of penetrating oil like WD-40 never hurts while attempting removals, although I think these screws are self tapping, so I dunno how much that'll actually help.

Best of luck, and let us know if you find success with any method.
 
Sorry for the delay, had a minor injury so I had to take a break for a while. However, despite trying all of the last few suggestions (impact screwdriver, pz-60, JIS screwdriver set), I still can't seem to get the last screw out. In fact, I think I may have made it a bit worse.
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At this point, I don't really even care if the screw itself remains intact or not (all of the other screws are fine anyways and have been cleaned + de-rusted), I just want to get it out. I've considered an extractor bit, but I'm a bit worried about damaging something. Should I go this route?

On a side note, what type of security bit do I need to remove the panel with the power switch on the back?
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Screw extractor. Home Depot sells them and they’re cheap. Don’t last long but work.
 
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A bit of an update; this is going to be a long post. Finally got the screw out after several attempts with different tools. What ended up working was going back and forth with an extractor set and PZ-60 pliers. Once I got the self-tapping part out of the metal it was downhill from there.
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In the mean time, I also cleaned up the chassis, first pic is how it looked initially:
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Thanks to this I finally got a closer look at the chassis since I can finally see it clearly now, and there are a few points I'm a bit unsure of. One thing I noticed is that some of the potentiometers seem to have a kind of epoxy or adhesive around them
tv5KoMB.jpeg
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Here's a look at the underside traces for the C952 cap, should I be able to solder a new cap in here through normal means? There seems to be quite a bit of corrosion around this spot. Mainly worried about destroying the traces/pads in some way.
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While on the subject of the chassis, I also wanted to ask about these lines on the tube (which I haven't cleaned yet), as they seem to have been cut at some point. I'm assuming they're for ground, but I'm just wondering where they're supposed to go to.
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Other than that, everything else has been going well. Been cleaning and de-rusting the screws and other various parts without any issues.
 
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