Nanao monitor - intermittent (h-hold?) problem

[Kokapetl]

I encountered a strange problem yesterday with my Astro City 2 cabinet (Nanao monitor).

The screen was horizontally scrambled and wavey, and adjusting h-hold was able to change it but not fix it.
My initial thought was to try replacing the control panel pots but then I left the machine off for a day, tried it the following day and the problem was gone.

This has only happened once, but I imagine it will probably happen again some time soon.
Could this mean that something is on its way out? ..possibly due to overheating? (the cabinet is kept in a shed which can get very hot).

Many thanks.

[Kokapetl]

In case it's relevant, I may have not allowed sufficient time between switching the arcade off, and back on again just before this happened.
I was working on something and was testing out all my power switches / if the computer would automatically boot up etc.

[Kokapetl]

I think i figured out what was happening.

I have my computer and arcade running under separate power switches, it seems that I only have the display problem if I turn the arcade on without an attached game board (when using MAME).
I've been making sure to turn on the computer first so that there will be a signal coming in, and then the arcade and I haven't seen the problem again (yet).

Does anyone know if leaving an arcade on without a game board attached can do damage?
I imagine the lack of a load could interfere somehow but I don't know a great deal about this sort of thing.
Thanks.

[gokun]

very generally speaking it shouldn't hurt anything...I often leave min on for extended periods when I'm working on them, or even wiring them and it's never been an issue other that the occassinal spark or shock hehe. just my 2cents...i'm no expert though

[MonMotha]

The monitor shouldn't care.  The DC power supply you may have installed for a dedicated game board might not like running with no load, but most seem to just shut down safely.

What may be happening is that the PC may be able to "detect" the monitor connected when it's off (since the inputs may be fairly low-Z when there's no power) but not when it's on (as the inputs may go fairly high-Z relative to the 75ohms the PC expects).  Sounds odd, I know.  If it doesn't detect a connected monitor, it may run in a different than intended "default" mode.  Try either "forcing" that the monitor is connected on the appropriate output, if your driver allows that, or strap some ~75-100 ohm resistors between the RGB signals and ground at the input to the monitor (you may need to turn up contrast or get a video amp, then, unfortunately).

What model monitor is this?  Is it a multisync?  Does it have a PC style HD15 input for video or just something more "arcadey"?

[Kokapetl]

Thanks for the replies.

If it doesn't detect a connected monitor, it may run in a different than intended "default" mode.

I think you may be right.. i noticed that even when the display would screw up, for the first few seconds (while displaying the bios screen) all was okay.

What model monitor is this?  Is it a multisync?  Does it have a PC style HD15 input for video or just something more "arcadey"?

it's a 29 inch, 15/24 kHz Nanao MS8-29FSG (one of the defaults for the Astro City 2 cab).
The only connection other than the control panel is a fat square plug with many connections (I can't remember how many).