Neo Geo Monitor blowing fuses.....

Bendiesel

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The monitor on my dedicated Neo Geo 4 slot recently went dead. I left it running for a few hours and when I returned it smelled liked a curling iron was left on too long. The monitor was completely blank, and the neck didnt light up. I checked the voltage, which seemed fine (128V). I pulled out the board and found that the fuse had blown. I replaced the fuse, and it immediately blew again.

Other than hiring someone to fix it, I dont know what to do. Im a total newbie when it comes to working with monitors, but im not afraid to get my hands dirty so to speak. Could anyone help guide through this? Or give me any advice?

I found these numbers on the monitor:

GA63ADGg25X
04RC0105-005
WG-502928

here are some pix (if it helps)

http://picasaweb.google.com/BenjieSell/NeoGeoMonitor?locked=true

Thanks for any and all help,
Ben
 
Ok... I was able to detirmine that it is a WG K7000. After spending some time with a multimeter I can away with these readings:


Ohm reading Diode Check

D19 .3 mOhm 0.534
D20 .3 mOhm 0.545
D21 .3 mOhm 0.545
D22 .3 mOhm 0.534
R103 3.5 Ohm
HOT 8 Ohms
IC4 174 Ohms

The Flyback is the older version with the white knobs, so Im already going to replace it, but does anyone know if that could be the only reason that the fuses would blow? I havent found anything else wrong....

Thanks,
Ben
 
You must remember what the fuse is there for.........

It is NOT to protect your chassis - it is there to stop your house from buring down when something goes wrong!!!

There are dozens of things that can cause the fuse to go open circuit.

Diodes that rectify the mains voltage
Transistors and diodes in the power supply voltage regulator
Horizontal output transformer that drives the flyback transformer
shorted yoke windings

and just about anything else.

If you have limited knowledge in monitor chassis repair it is best left to the experts

Also consider the LETHAL voltages floating around on the chassis - do you know where it is safe to touch and where it is not???
 
Everything was discharged and checked for any reisdual charges prior to taking apart. What I'm asking for is guidance in troubleshooting. I appreciate the warning, however.
 
Everything was discharged and checked for any reisdual charges prior to taking apart. What I'm asking for is guidance in troubleshooting. I appreciate the warning, however.

right here:

Diodes that rectify the mains voltage
Transistors and diodes in the power supply voltage regulator
Horizontal output transformer that drives the flyback transformer
shorted yoke windings
 
You must remember what the fuse is there for.........

It is NOT to protect your chassis - it is there to stop your house from buring down when something goes wrong!!!

There are dozens of things that can cause the fuse to go open circuit.

Diodes that rectify the mains voltage
Transistors and diodes in the power supply voltage regulator
Horizontal output transformer that drives the flyback transformer
shorted yoke windings

and just about anything else.

If you have limited knowledge in monitor chassis repair it is best left to the experts

Also consider the LETHAL voltages floating around on the chassis - do you know where it is safe to touch and where it is not???

The fuse is there to protect the chassis from further damage. The breaker for the AC circuit is there to protect the house.

Straight from answers.com...

The purpose of the fuse is to protect the equipment receiving power from overload or short circuit. Having no fuse could result in destroying the equipment and/or a fire.
In buildings the fuse protection (or circuit breakers) also protects the building wiring.
 
Im on it heh.. Hes a local boy.

Its got a white knob fly thats obiously blown ( theres your smell man)
that killed the hot. That shorted c36 and the v reg. Dioded checking ok. ALso has one bulged cap that i will replace..

Have most of the new parts in and will repost once i get it working..
 
I've got one right now with a bad replacement flyback that was only in use for not even 3 months. This one has a date on it 2003.09.02

My flyback ringer tester says it's bad (shorted). The flyback took out the horizontal output transistor and the voltage regulator before blowing the fuse.

I've already tested the other diodes and capacitors in the horizontal section (including both C36 and C38) and they test fine.

Lately, I've had THREE replacement k7000 flybacks fail shortly after installation.
 
well mabye im barking up the right tree then. THis fly was gotten from a monitor guy , a whole other story id rather not get into, but it looked like it was new but had been in and pulled before i got it

Ive had no luck with it in 2 chassis now, im pterry convinced that this dude knew what he was doing.


will get another fly from bob and post back to let you know if i got a trojan flyback :D
 
Well its not a trojan fly lol. put it in a workign chassis and the fly is o.k. so its somethign else with this frickin board.

ben- to get you done i went through another chassis, its ready to go lmk when you want to pickup.

i will continue on with this though, this was the 2nd chassis ive dealt with in a row that blows fuses " for no good reason"
 
to close this out i basically gave up on the original chassis and rebuilt another chassis for ben. Hes happy. I will dig into this chassis from hell when i get some time..
 
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