general question about monitor troubleshooting

Cartouche

New member
Joined
Dec 5, 2007
Messages
679
Reaction score
3
Location
Southington, Connecticut
I'm just starting to get into troubleshooting non-working/faulty monitors and am looking for a confirmation on something. I'm sure there are exceptions to this, but in general, let's say you have a common raster monitor like an Electrohome or Wells-Gardner that shows a blank screen. Cranking up the screen control on the high voltage unit has no effect.

What would be the first couple of steps to diagnose? From what I've read, it looks like you would:
1. test to make sure fuse isn't blown
2. measure B+ voltage

Is this accurate in general?
 
From my experience a blown fuse won't produce a picture at all unless that's what you mean by a blank screen. No B+ would also cause no picture or distorted picture if juice is getting through but is out of adjustment..
 
The next step would be to see if it has high voltage and/or neck glow. If neither, then check the fuse and go from there. If the fuse is good, check the board for bad solder points, burnt traces, etc.

Try to find randy froms flow charts - that'll give you a good list to go by.
 
Just so I understand you correctly, you would check for neck glow BEFORE the two tests I mentioned (fuse and B+ video)?

When you say "see if it has high voltage", by that do you mean testing the high voltage unit (flyback)?

The next step would be to see if it has high voltage and/or neck glow. If neither, then check the fuse and go from there. If the fuse is good, check the board for bad solder points, burnt traces, etc.

Try to find randy froms flow charts - that'll give you a good list to go by.

Yes, Robran68, by blank screen I mean no picture at all.
 
There is not a simple generic answer for arcade chassis boards being they all are different and don't show a picture for different reasons. You are right about the fuse being that is an obvious reason for no picture. Now a blown fuse could be a bad flyback or HOT but other factors could be the cause.
 
I see. I guess that would be too easy, huh?:)



There is not a simple generic answer for arcade chassis boards being they all are different and don't show a picture for different reasons. You are right about the fuse being that is an obvious reason for no picture. Now a blown fuse could be a bad flyback or HOT but other factors could be the cause.
 
I think the working/non-working situation is a lot easier to troubleshoot than the works but has a small problem with color, horizontal linearity, waves, ect...

I can manage to install a fuse, flyback, hot, and capkit, but troubleshooting the small problems are tough for me. I think we just need to go back to mechanical scanning and screw all these electronics. :)
 
Well there are basics to look at - not every monitor is the same, but as far as basic troubleshooting they all need a few basics - power, video signal, neck glow, and high voltage.

Just logical things...IE..

Ok - no picture, but is it *really* dead? Lets check for a pulse...
Neck glow...check...high voltage...check
Ok seems to be somewhat functional...lets crank up the brightness...ah there we go.

OR

Ok - no picture, but is it really dead...
Neck glow....nope (immediate no picture scenerio)...high voltage...nope...
Unplug power connector and check for juice...hmm nope
Check fuses in power brick...ah blown fuse

When I say check for high voltage - usually you can hear it working, or put the back of your hand near the screen (on the front where the pic usually is) and feel static. Another way I've used sometimes is take a piece of napkin or paper and hold it near the tube - if it immediately sticks, it has or at least had high voltage.

BTW a lot of people pretty much assume that neck glow and high voltage go hand in hand. They do for the most part, since often the 6v for the heater comes from the flyback, but there are exceptions, like vectors, where the 6v heater supply comes from the power brick. Thus, on a vector you can have high voltage but no heater.
 
In the past month I have worked on a variety of monitor boards with different problems and I will tell you almost EVERY one of them had cold solder joints!
 
Step 1: Make sure game is on.
Step 2: Check for AC input.
Step 3: Turn up brightness.
Step 4: Check fuse.
Step 5: Check for neck glow.
Step 6: Check for B+.
Step 7: Remove chassis and check for burnt/exploded parts/flyback.
Step 8: Check Voltage Regulator and HOT.
Step 9: Install complete cap kit and new fuse, VR, HOT, or flyback as necessary.
Step 10: During parts installation, inspect entire chassis for cold solder joints.
Step 11: Reinstall chassis and hope it's fixed. If not...
Step 12: Trace voltages through circuitry utilizing schematics, looking for bad parts....
 
Back
Top Bottom