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Main => Monitor/Video Forum => Topic started by: battles on October 03, 2012, 10:39:25 pm

Title: Neo Geo MVS Squished Screen
Post by: battles on October 03, 2012, 10:39:25 pm

I just purchased a 2 slot Neo Geo MVS cabinet, but the monitor is fairly dark and even after tweaking the screen controls, NEVER quite fills the monitor screen.

Do I need a new monitor, or is it something more?

Thanks.

Title: Re: Neo Geo MVS Squished Screen
Post by: juanchocnva on October 03, 2012, 11:16:02 pm

pics??
model?
stuff??

how many inches to fill screen

Title: Re: Neo Geo MVS Squished Screen
Post by: MonMotha on October 04, 2012, 04:25:23 am

Most US Neo-Geo multislots seem to have a k7000 or clone (Kortek) in them.  In general, cap it and it'll fix most of your problems, including the ones you describe.

Most "cap kits" don't include the big smoothing cap on the output of the rectifier near the AC input.  I've had them go bad and cause all sorts of problems since B+ is then ripply.  You may want to consider replacing that too, though it can be a bit expensive.

To address the direct questions at hand:  which controls have you adjusted and how?  Is it not filling the screen horizontally (too narrow) or vertically (to short)?

Title: Re: Neo Geo MVS Squished Screen
Post by: battles on October 04, 2012, 10:08:53 am

Thanks for the help! I've attached photos of the power control, which I've been using to tweak the monitor size, placement, contract, etc.... and monitor. My apologies for the quality :/

(1) In general, I've been tweaking the V-hold & V-pos knobs on the power control

(2) The monitor is not filling the screen vertically

I've tweaked the setting a ton with no luck.... anything I should try at this point?

Title: Re: Neo Geo MVS Squished Screen
Post by: grantspain on October 05, 2012, 07:30:03 pm

looks like fault in vertical deflection circuit,might be just a cap

Title: Re: Neo Geo MVS Squished Screen
Post by: battles on October 07, 2012, 01:35:33 pm

Ok, well after searching around more, I ordered a cap kit for the qnic cgm-2500, which I'm pretty sure is the monitor.

Three more questions:

(1) Will I need to discharge the monitor prior to installing the new cap kit?

(2) Will the cap kit help with the monitor brightness? It's pretty dim...

(3) If the cap kit doesn't fix the vertical stretch issue or brightness, will I then need a new monitor? If so, where can I get one?

Thanks for your help, I really appreciate it!

Title: Re: Neo Geo MVS Squished Screen
Post by: grantspain on October 07, 2012, 02:04:03 pm

yes discharge and remove chassis when doing any work like this,install each cap one at a time and note the polarity as the circuit board sometimes lies

cap kits are a shotgun job,lots of time they sort many issues out-both of yours could be cap related.
a low b+ or cap on the g1 would cause brighntess issue.The vertical foldover is a common cap issue on many chassis but sometimes it could be down to a failing vertical deflection ic or a open circuit resistor.

of course check for bad solder joints when doing this work

a replacement chassis would depend on size of tube,neck pinout,deflection yoke readings and of course voltage input

i am not familiar with your chassis so can't say what chassis will fit