astro city monitor doesn't power on

[kyuzo]

Hey guys, sorry for another noob question I dug around for a while in search but couldn't find anything...

After moving, one of my astro cities doesn't actually power on its monitor at all anymore. I found a powery-looking cable hanging loose in the back so that seems suspicious enough, but looking at my still functioning astro city I can't actually see where it's supposed to go. The wire goes from the left side of the monitor (when looking from the front) over the top and hangs loose about a foot below the monitor pcb now. On my functioning astro city I *think* it goes down on the monitor side of the pcb, so I'm assuming it plugs in somewhere over there?

Does this sound familiar to you guys?

Thanks and apologies again for how bad I am at these things

[dieKatze88]

Got some pictures for me? I have a New Astro. should be close enough.

[kyuzo]

Somehow my iphone camera's flash didn't want to fire at all, so the picture of the inside of the cab is miserably dark, but I'll take a better one with a proper camera tomorrow. I did get an okay picture of the loose cable and connector though (is it me or is it strange to have a red/red cable pair?)

http://s1169.photobucket.com/albums/r508/kyuzo1/

Thanks

[Dave_K.]

Looks like the degauss wire. That shouldn't prevent the monitor from working.

Are you saying the monitor doesn't work, or the cab doesn't power on? Can you hear a game playing and just no picture? Otherwise have you checked the switch in the back of the cab as well as the one on the power supply are both turned on?

There is only one wire/connector that goes from the power supply to the monitor. And that should be simple to see if its still plugged in as its on the side of the chassis. If your monitor is rotated, this connector would be facing the bottom. If its setup horizontal, its on the left side of the chassis.

[kyuzo]

Everything seems to work other than the monitor... Games play and the light above the monitor turns on just fine. The led on the little monitor pcb turns on too... (I'm 99% sure, I'll double check again at work tomorrow though) As far as I can tell the monitor itself is just not doing anything whatsoever...

[Dave_K.]

The led on the little monitor pcb turns on too...

I assume this is not the original monitor then, as there are no LED indicators on a Nanao chassis or remote board. Without knowing what monitor you have, or how it was hacked into the cabinet power supply and jamma loom, there is little we can do to help you troubleshoot it.

Aren't you located near me in SJ?

[kyuzo]

Lemme double check and take some pictures, that can't hurt either way I'd be kinda sad if it's not the original monitor (then again, I guess I didn't notice, heh)

Yeah, though my cabinet's at work in Menlo Park right now... If all else fails can I bribe you with lunch or something to take a look at some point?

[kyuzo]

Turns out I was just on crack about the LED Not sure what I was thinking, the only thing close was a few places where the marquee light reflects off of some metal? Sigh...

I added a few pictures of the insides, though I'm not quite up to date on my terminology of what exactly is what... Just for future reference does chassis just refer to the pcb part that has the picture adjustment pots right by the monitor or is it everything that mounts onto the actual tube? Also, is the remote board the one that's inside the control panel? Or is it the small one that's right by the back of the tube?

Thanks again for helping with this stuff guys

[dieKatze88]

Does the game being played make sound?

That looks like some kind of Nanao PCB, and it's using an Astro wiring harness, so It looks pretty legit.

I received a similar set of symptoms when I accidentally shorted Video Sync to Ground. The MS9 I have has a built in protection mechanism and basically refuses to turn on for 30 minutes, but after that everything was fine. Look around for bare wire touching things.

[kyuzo]

Ah thanks, I'll check that

Yeah the game seems to be perfectly fine, it's just the monitor... The wiring is definitely kinda shady in places, it wouldn't surprise me if that's the problem

[kyuzo]

I couldn't find any exposed wires that were actually touching anything (man I need some electrical tape at least), but I did get a vaguely tingly sensation from touching the actual cabinet metal a couple of times, could this whole thing be a grounding problem? I should be able to ground the little metal nub by the external power and solve that right?

[Dave_K.]

You can safely operate the cabinet without the grounding lug in the back connected (at least in most cases), so thats not the problem.

Also good news that the updated pictures confirm you have an original chassis. The board attached to the back of the tube is called the Neck Board. The chassis is the PCB that sits under the tube, and remote board is whats under the control panel.

From the pictures it looks like your neckboard, yoke lines, and deguass and jamma inputs are all hooked up correctly. You might want to make sure the remote board under the panel is connected firmly. Now that I see the degauss wires connected to the chassis, I'm not sure what the dual red wires are for that is disconnected. It looks like its hacked to the deguass line in that one picture with black electrical tape. Could be this is a tube transplant, and the person had hacked to deguess lines since there is a difference between some chassis connectors. Just leave it disconnected.

So with all connectors looking decent, next thing to check is do you see any glow in the tube (near the neck board) or hear any static like sound like the monitor is trying to power up? If there are no sounds from or glow from the monitor then either power isn't getting to it, or a fuse has popped, or worst case the HV circuit on the chassis is preventing it from starting (a fault on the chassis).

Check to make sure the connectors coming out of the power supply inside are all securely latched. If you have a multimeter, you should test to make sure 110v is coming into the chassis via the large square connector on the side (just unlatch it, and check between the black and red wires).

After checking all the above, and you can confirm power is getting to the chassis, then its likely something on the chassis PCB HV circuit went bad...and will need to removed from the cabinet and serviced.

[kyuzo]

Cool, thanks for the reply

[kyuzo]

So Dave_K came by yesterday and we spent a while looking at what was going on. We measured the power to the monitor chassis being fine and checked the fuse on the chassis, which was fine too. To figure out if it was a problem with the tube or the chassis we transplanted the chassis from my working astro city, and everything worked fine. At this point we were pretty sure the chassis was the problem, but we decided to measure the power actually getting to the neck board just to make sure we narrowed down the problem as much as possible. When we hooked the chassis back up, somehow everything came up just fine.

...

...

Well, it works now, I guess I'm happy

The only things we did that might've made a difference was unplug and replug all of the connectors, and we reseated the chassis in it's mounting bracket. Somehow the previous owner had inserted it in a weird way, so the chassis was flexing slightly and sitting on top of the monitor cables initially, so our only theory is that there might be a loose connection that got connected again by not having the chassis flexed...

Thanks Dave_K

[rugdoctor]

My converted naomi monitor chassis also had this problem and sure enough, by having it sitting flush on a wooden board sorted everything out. Nice to hear everything worked out for you!

[Dave_K.]

I was really surprised it worked when we put it all back together, but then again, without seeing any other physical damage to the components on the board, I guess a cracked solder joint due to the flexing makes a lot of sense, especially when moving the cab could make it flex more.

With the chassis seated properly in the frame now, I doubt you'll see this particular problem again anytime soon.