Monitor just died on me.

[HarrieD]

A while ago, when switching on my cabinet no picture was being displayed. Today i'm checking out the game and notice that the monitor has no neckglow and is "ticking". A very distinct ticking that is at approximately 50 Hertz or so. I guess my monitor just died and that the problem is in the power supply. Or is it the flyback that passed away??
Does anyone have some experience in this area?

It's a neo-geo cabinet with a (yes, i know) 60 in 1 jamma board and an intervideo (??) 25" monitor.

[iankellogg]

I am going to guess your monitor is a K7000. Would be nice to verify that with a photo or something.

But going on that assumption your HOT probably is dead. The clicking sound you are hearing is the B+ supply dealing with a short circuit somewhere on the PCB.

[HarrieD]

I will post a pic. Thanks for your quick reply.

[iankellogg]

I completely missed your comment on the intervideo monitor. but what i said still holds true for the intervideo. The hot is probably dead. To check, remove Q3 which is a BU503 and do a diode test across it. pretty much measure every pin to every other pin. if there is a 0V (short) on any of those pins then thats your problem. If the hot is fine then you will have to do a LOT more digging.

[HarrieD]

It's this one:

http://www.andysarcade.de/data/coinop/videogames/raster%20monitors/intervideo/intervideo_vp_series.pdf

Mine is version 6, manual is for version 4. (22.0329.4).

I will check Q3.

[HarrieD]

Okay,  desoldered it, it reads each 2 times: 0.012 0.026 and 0.035 volts. (Measured it 6 possible ways)
That thing is dead. Will order a new one this week.

Thanks for the help so far. I will update once i've got more info.

[iankellogg]

oh yeah, thats dead.

[HarrieD]

Replaced Q3, measured it before putting it in, and got .5 or so 2 ways. So that one is good (or was good for that matter). Still the same issue unfortunately. I still hear it ticking distinct, at about 50Hz or so.
Next step: i will check out all the transistors in that area.
Is it possible this is caused by a defective flyback???

I will also recap this thing.

I noticed the image was a little unstable from time to time. It glitched out of sync for a few frames and the image was sometimes briefly shaking.

[iankellogg]

it is possible the flyback is causing this but i am not sure, i haven't personally seen a flyback cause a main power supply short before.

The one annoying thing about these types of monitors is the power supply will click if there is an overload or there is no load. So its possible that almost everything is fine and there just isnt a load on the supply.

I would go ahead and cap it. If there is a bad cap somewhere it can cause a no load failure.

[HarrieD]

A flowchart is available, will check that out.

[HarrieD]

I followed the flowchart on page 8.  Measuring the voltage on cathode of D12, must be >= 149Volt. Is around 3.5Volt.
Disconnected the yoke, now it measured 189 Volts. So, according to flowchart Q3 and D16 can be defective. Allready swapped Q3, so D16 can be an issue too i guess.

[HarrieD]

Okay, desoldered D16, it measured 0.5V, the correct way. So i guess that one is good. Hmmmpf, what now???

[iankellogg]

Do a cap kit. As i said before, you don't know if it is failing from a short or from an underload. Its entirely possible you just have a bad cap.

[HarrieD]

Okay, will do. Thanks again.

[HarrieD]

Recapped the shit out of this thing, still no improvement. Can a diode be defective even though measuring it gives a normal value??