Troubleshoot Sanyo EZ-20: No Picture

[gar0u]

About 16 years ago I bought a Gumshoe cabinet that was converted from a Donkey Kong cabinet.  I converted the cabinet into a dedicated MAME cabiniet, and have been learning a lot about the hobby off and on since then.

The monitor in the cabinet was a Sanyo EZ-20.  I've moved the cabinet about four times since I acquired it.  Each time I moved it, I unbolted it from the cabinet, and moved it by hand--except the last time I moved it.  A professional moving company moved it using a dolly, down two stories, and back up two stories; stairs both ways.

Now there is no picture on the monitor.  I've isolated the problem to the monitor by switching out the EZ-20 with a VGA monitor.  (I'm using MAME and ArcadeOS, and edited the config file, and recabled.)

There is a high-pitched whine in the monitor, and an orange glow in the neck of the monitor.

I'm not surprised there is no picture after the beating my cabinet took in the move.  But I don't know how to begin troubleshooting the issue.  Knowing that the monitor worked before this mistreatment, can you think of any likely things I could check?

[baritonomarchetto]

If your neck glow is there i would suspect a signal loss. Turn yout monitor on, rise the "screen" potentiometer on the flyback and look at the screen

[mgb]

First off it's something to be very careful with if you have no experience with monitors.

I'm assuming this has worked before the move?

if you have neck glow, then It's powered and would appear to have a functioning flyback. check all connections.
I'm assuming you have some sort of inverter on here being that 20ezs are backward to regular monitors as far as video signal goes.

[gar0u]

Yes, it worked great before the move (and after several other moves when I was more careful about moving the cabinet).

How do you "rinse" the screen pot?  I thought you might mean the brightness setting, and I have moved that to its stops in both directions while looking at the screen.

I believe it does have the color inverter board.

What connections should I be checking?  There are some molex connections that I checked; not sure if there are other connections that perhaps don't look like connections?

Is it possible a fuse was damaged that would allow the monitor to "power up" but not display a picture?

I know my way around low voltage electronics, but not monitors; I have a healthy fear of it, which so far has prevented me from doing much poking around.  Eventually I plan to discharge it, remove it from the cabinet, clean it, and do a cap kit replacement.  The cap kit I bought is now about 15 years old.  Is it still good if the caps haven't been used, or are they old and dried up, too, now? 

[mgb]

You 15 year old cap kit is most likely still fine.

What he means about raising the screen knob is, on the flyback transformer, there are two knobs.
When looking at the monitor from behind the cabinet, the flyback to the right. It's typically covered by a metal shroud but has two access holes for the adjustment knobs.
The left knob should be focus and the right one, screen ( verify which is which as I may have it backward)

Turn down your brightness to halfway before doing this.

Another important step on those monitors is adjusting the B+ voltage to the correct 108 volts.
This can be a little bit of a pain if your not used to doing it.
You can google it for a video on the steps to take.

[obcd]

If the monitor became bad during transportation, I doubt a B+ adjustment or a capkit is what it needs.
This doesn't mean that it's a bad idea to do once the monitor is working again.
Basically, you should carefully visually examine the pcb for bad solderings. Those can finally make bad contact when the monitor chassis is getting shocks and vibrations during transportation.
Just make sure you know how to discharge the tube for the removal of the anode cap. Make sure you discharge again before you put the anode cap back in place. Try to locate where the high pitch whine is coming from. The bad soldering might be in the same region.
Suspect the solderings of the larger components like the THT transformer and the high power resistors. Connector solderings and adjustable resistors can become bad as well due to aging.

[mgb]

If the monitor became bad during transportation, I doubt a B+ adjustment or a capkit is what it needs.
This doesn't mean that it's a bad idea to do once the monitor is working again.
Basically, you should carefully visually examine the pcb for bad solderings. Those can finally make bad contact when the monitor chassis is getting shocks and vibrations during transportation.
Just make sure you know how to discharge the tube for the removal of the anode cap. Make sure you discharge again before you put the anode cap back in place. Try to locate where the high pitch whine is coming from. The bad soldering might be in the same region.
Suspect the solderings of the larger components like the THT transformer and the high power resistors. Connector solderings and adjustable resistors can become bad as well due to aging.

True, I only mention the b+ adjustment because it sounds like he planning a cap kit anyway.

[menace]

I just worked on a slightly different model of a sanyo and it had a little daughter board stuck to the top of the metal cage that surrounds the flyback--the signal cables (red, green, blue etc.) came into this thing and they were very easy to slip off in my case--check that.

Also check all the connections at the gameboard side of things as well--basically tighten every plug and wire that you can..

[gar0u]

Menace, that sounds like it might be a color inversion board.  Not sure though.  I am still very new to monitors!

I have discharged the monitor (with the help of a friend who is a EE), so I have the homemade tool to do it.  Still makes me nervous, but I know how to do it safely.  I will discharge it and take a closer look at everything soon.

Hoping it is a knob adjustment, or a loose plug now that I know where to look, but I suspect a bad solder joint knowing how it was likely mistreated in the move. 

Will likely install the cap kit and check/set the B+ voltage as well.

Thanks everyone.  Will report back with my success or more questions...