monitor is very dark. help plz.

[F_Zero45]

I have a wells gardner 25k7193 and my picture is way dark. Adjusting the contrast makes the colors neon like and the blk level makes the entire screen either pale/faded or very dark. I cannot get a crisp picture. I tried different game pcbs and it's dark so I know it's not the game board but something with the monitor. I also tried adjusting the 'screen' dial on the flyback, i believe is what it's called, and it doesn't fix the problem but pretty much does what adjusting the blk level does.

[F_Zero45]

Also to play at night I have to turn the overhead light off to see the screen b/c it's so dark.

sorry for the double post. my edit isn't working

[Ken Layton]

And you've done a fresh capkit on it?

[F_Zero45]

not a fresh one.
The last time it was capped was less than a year ago and then went into storage. I just bearly started using it about a month ago.

[grantspain]

it is always worth checking the power supply +5 is adjusted correctly as this can cause the same problem.
if still no joy then try adjusting the neck board colour gains and background,don't forbet the contrast pot as well
i usually set my monitors by turning all the colours backgrounds and gains,brightness and contrast to minimum then turn the screen volts so you can just make out a pic,then add a bit of brightness,then add contrast a little,now add a small amount  of each colour background then the colour gains.use a colour bar from a test menu to help

[F_Zero45]

checked voltage and replaced ISO transformers but still the same thing.

[grantspain]

checked voltage and replaced ISO transformers but still the same thing.

have you done the other things i suggested yet?

[Ken Layton]

There are 3 non polarized electrolytic capacitors near the video input connector. These do go bad, but they are not included in the capkits. These caps go open circuit and cause a sharp drop in picture brightness.

Also, remember that capacitors (even new ones or fairly new ones) can fail at any time for any reason.

[Kevin Mullins]

i usually set my monitors by turning all the colours backgrounds and gains,brightness and contrast to minimum then turn the screen volts so you can just make out a pic,then add a bit of brightness,then add contrast a little,now add a small amount  of each colour background then the colour gains.use a colour bar from a test menu to help

Ditto ....
Turn everything down and adjust the SCREEN voltage pot on the flyback until a pic starts to show. Then re-adjust the rest of the brightness, contrast and color pots to suit you.

If this isn't enough then go with the caps Ken mentioned.

[F_Zero45]

so what you're saying is to turn down contrast, brightness and ALL red, green blue pots down all the way and then using the screen pot on the flyback turn it until i get a picture then add the colors and contract?

[F_Zero45]

OK. I tred it and it didnt seem to fix the problem.
it's probablly what ken said.

[Ken Layton]

If yours has a ZENITH picture tube it's possible it may be going bad and might need to be rejuvenated.

[F_Zero45]

Ken, can you give me more info on the 3 non polarized electrolytic capacitors? ie. where are they(pic of possible) where can I get replacements

thanks

[Ken Layton]

C4, C5, C6. Located near integrated circuit IC1. All three of these caps are the same value: 10 uf @ 25 volts non-polar. Bob Roberts should have them.

[F_Zero45]

Thanks. that did help but now. it's like there is no white color. I go to like a color bar test and the block that should be white is a dark grey

[F_Zero45]

Anyone?

ken?

[grantspain]

whats the video source??

[F_Zero45]

First I tried a pc using arcade VGA then I put in my Mortal Kombat board and both show same thing. The picture is there and colors are good but in the diag test  , or anything for that matter, white shows up as a grey color.

[grantspain]

and it stays grey when you turn up the brightness/contrast or screen volts?
the red/green and blue are rich without ghosting

[F_Zero45]

It only turns white when I turn the contrast up all the way but that ruins the clearity of the picture

[grantspain]

well its either the tube dying or your setting the colours/contrast/brightness/screen volts/focus badly
i had a sanwa monitor do a similar thing whereas all the colours were present but you could not get richness and clarity,no matter what adjustments i made i could not get it perfect-in the end i swapped the tube and hey presto a perfect picture and this monitor was only 3 years old on a sega outrun 2
maybe you gonna have to adjust to the best pic and live with it

[Ken Layton]

Put the tube on a rejuvenator to analyze the internal condition of the tube. As I asked before (but did not get an answer) is this a Zenith brand tube?

[F_Zero45]

Sorry, it is a Zenith. Whom woul I go to that would have a rejuvenator?

[F_Zero45]

here's a pic. the middle bar is supposed to be black and the top and bottom bars are supposed to be white. The blk level is down all the way btw.

[Ken Layton]

Looks like the focus adjustment is way off. I think you've got a weak tube.

Many tv repair shops have a rejuvenator. Cost is between $35 to $75 to have them test your tube and rejuvenate if needed. You'd need to bring them the entire monitor.

Some forum members here own rejuvenators and one may be located near you. Suggest posting a thread asking for assistance near you.