Monitor is rapidly turning on and off!

[Rick]

My monitor has been rapidly turning on and off for I while, and I cannot seem to locate the problem. The game will keep running and the sound keeps going, but the monitor will flash on and off until I unplug and replug the MVS harness or jiggle the MVS harness. It will flash on and off a couple more times and eventually it will stop and it will be fine, at least until the next time I turn off the MVS and have to repeat the proccess over and over. I don't know if the problem stops because I'm jiggling the right wire or if it stops for other reasons?? I bought my Wells Gardner monitor brand new 2 years ago. I'm not sure the problem lies with the monitor or what? Please any suggestsions will be greatly appreciated!!

 

[StealthNinjaScyther]

I'd say to check your power supply first, tends to be at the source of most problems.

 

[SuperGunGuru]

I'd check the MVS harness and make sure the wires that connect to the monitor are nice and secure. Can you tell if the monitor is fully losing power or is the screen just going black? Check to see if the neck of the monitor tube is glowing.

The power supply doesn't provide the monitor's power. The power comes from an isolation transformer (most monitors require them, but some newer ones don't) and is seperate from the power supply's output.

 

[Rick]

What I noticed yesterday is I left the machine alone and it stopped doing it by itself. It seems after the machine warms up, it isn't an issue any more; it just does it for the first few minutes???

 

[ttooddddyy]

It sounds to me like a problem with the monitor pcbs power supply circuitry (not the game boards 5/12 volt psu) maybe a flakey electro cap, perhaps a cap kit will fix this, I realise that the monitor is not that old, but even so a faulty electro could cause the "squegging" or poor regulation you describe. Also check the +B voltage, let me know the model # of the monitor.

 

[Rick]

Actually, the tech at Wells Gardner suggested the same thing (checking B+ voltage). I don't have the monitors model# handy, but it's their 25" replacement specifically for the 4 Slot MVS. Honestly, I don't know how to go about checking the B+ voltage;maybe you can help??

On a side note, yesterday I turned on the machine and I didn't experience the problem at all; everything worked just fine...

 

[::J@mm::]

Had that problem once on a Monitor I had,

same thing on and off warms up doesent do it, latter on I thought it was ok,

and one day DAMN!!!

had to replace it!!

may wanna leave it alone until you can actually chet it and not use it till then

 

[ttooddddyy]

Actually, the tech at Wells Gardner suggested the same thing (checking B+ voltage). I don't have the monitors model# handy, but it's their 25" replacement specifically for the 4 Slot MVS. Honestly, I don't know how to go about checking the B+ voltage;maybe you can help??

On a side note, yesterday I turned on the machine and I didn't experience the problem at all; everything worked just fine...

With the model number of the monitor I may be able to help

 

[Rick]

I finally found the instruction book to the monitor:

The model # is Wells Gardner 25K7401

Here's a few more tidbits:
It seems like if I turn the power on and of 20 or so times, the problem eventually corrects itself. Also, it seems like the volume gets louder as the machine warms up, so it seems like when the volume is quieter, the problem with the monitor persists. However if the volume seems louder, than the monitor doesn't act up?! does that make any sense?

I'm almost certain it's a power supply issue; either the machine power supply or the monitors.

 

[chris1]

I finally found the instruction book to the monitor:

The model # is Wells Gardner 25K7401

Here's a few more tidbits:
It seems like if I turn the power on and of 20 or so times, the problem eventually corrects itself. Also, it seems like the volume gets louder as the machine warms up, so it seems like when the volume is quieter, the problem with the monitor persists. However if the volume seems louder, than the monitor doesn't act up?! does that make any sense?

I'm almost certain it's a power supply issue; either the machine power supply or the monitors.

I'd say you have to go over the wiring..Make sure the Jamma harness is on right.
Make sure it's pins are clean and the edge connector clean..

With the power supply I'd say you really need to get a voltage/digi meter and take some readings.

I'm all for buying a new power supply and if you have the cash I'd say go for it.
Thing is:..The New power supply will have to be voltage tested anyway IMO..
I don't know what they set them at factory....who knows..there's no guarantee the power supplies +5V will be set right..
It could be to high or low when you get it...(All it takes is someone to turn that knob)