NBA JAM - part of screen darker

[BulkOfTheSeries]

So I am working on a NBA JAM that was dead when picked up.

The PS was toast so I dropped a new one in and the game fired right up.

The voltages are good.

Everything works great except for roughly 20% of the image on the left side of the screen is noticeably and significantly darker. It's tough to tell in the photo I provided but when the game is running the area is not 'blacked out', the game is still visible.

I was unable to adjust it out using the pots.

My first thought is that this is a cap issue so I pulled the chassis for rebuild. Hoping this is not a tube issue. Is this a common failing due to cap or flyback issues? Looking at the chassis there is nothing that jumps out at me.

 

[demogo]

Try a cap kit.

 

[security0001]

So I am working on a NBA JAM that was dead when picked up.

The PS was toast so I dropped a new one in and the game fired right up.

The voltages are good.

Everything works great except for roughly 20% of the image on the left side of the screen is noticeably and significantly darker. It's tough to tell in the photo I provided but when the game is running the area is not 'blacked out', the game is still visible.

I was unable to adjust it out using the pots.

My first thought is that this is a cap issue so I pulled the chassis for rebuild. Hoping this is not a tube issue. Is this a common failing due to cap or flyback issues? Looking at the chassis there is nothing that jumps out at me.

i would definitely do a cap kit to start and maybe a flyback but before the flyback i would check the cap on the neck and try increase the uf rating on it. (original is 4.7uf 250v) try a 22uf 250v) (that is C204). put the whole cap kit in too. if you need them i have them on my site 100% nichicon 105c including bipolars the best quality caps.

 

[Mattspad]

Cap kit my dude Thats 90% of the time what causes that. K7000's used cheap caps.

 

[mecha]

TMNT at GGA is doing the same thing. it also has a wave and shuts down after awhile.

here's another area of importance you should address when installing caps. I put this together cause it's something I've seen a lot of the last few years.

 

[brainmegaphone]

If you look at the K7000 troubleshooting flow chart (google image search if you don't have it) it describes your problem as being C57. You should, of course, change all the caps... then see how it looks.

Plenty of great people on here sell the kits. I'm pretty sure 3-4 of them post their site links on nearly every monitor question post offering parts for sale... whether the person needs parts or not lol

 

[Buffett]

yup cap the chassis and change the fly.

Peace
Buffett

 

[mecha]

Randy Fromm, circa-1992 said it was extremely rare for a K7000 flyback to fail.

I personally think they're the biggest pieces of garbage ever