Inversed colors on a 25K7000

[SirPeale]

I'm working on a 25K7000 with a dim tube.  I finally made a CR-23 adapter for my rejuvenator and was able to shoot it finally. 

Afterward the colors are *inverse*.  I fiddled around with it and for a few brief minutes had all the colors correct, but then kept trying to adjust and it went inverse again.

New tube time?

[Kevin Mullins]

Inversed ?
Can't say that I've ever had that happen.

Have ya tried working with just one color at a time ?
By disconnecting the other colors via the video input.

Does the neckboard look good ? (cold solder joints and such)

[SirPeale]

Inversed ?
Can't say that I've ever had that happen.

Right?  That's why I'm perplexed.  At first I thought something happened to the test board I was using, so I tried another with the same result.

I haven't figured out how to get into test mode with this board yet, that's next on the list. 

Neckboard is fine. 

This was my first time using this rejuvenator, and it may not being working correctly.

[Kevin Mullins]

Does each of the color guns check good ? (emissions test)
Test for shorts ?

I would think worse case scenario would totally kill the guns, but not something wonky like you're describing.

I rarely even use the "rejuvinate" function on mine. Most of the time just run the "clear shorts" setup and it does wonders. The rejuvinate function on this one seems a bit harsh and down right scary when it goes off. (Sencore CR161)
 

[SirPeale]

I had bad emissions before and a really dim picture.  When I was rejuvenating it was like fireworks were going off in the neck.  I've shot a bunch of tubes before (never with this rejuvenator) and I've never seen that before to that extreme.

I do have another K7000 chassis I can test with, but it's untested as of late.  It's been on my workbench for the last couple years and I haven't exactly been gentle with it.

Weird thing is I did have a good picture - for a few minutes.  This is a head scratcher.

[SirPeale]

Swapped the tube today with pretty much a brand new tube.  Well...the tube is old, but out of a barely used TV.  Still has inverse colors.  Either inverse or it's missing a color.  Need to get some color bars on there.  Does Golden Tee '98 have color bar tests?

[Ken Layton]

Yes, I think it does have some kind of color bar test.

Have you tried new neckboard transistors and checked the large resistors on the neckboard?

There are three color preamp transistors on the k7000 mainboard and right next to them are three NON-Polar electrolytics. Have you tested replaced the non-polar electrolytics?

[SirPeale]

The monitor was fully working (though with a horribly dim tube) when I used it last.  Then it sat for about eight months until I plugged it in again.  IIRC I replaced ALL caps when I capped it, but I'll certainly check it when I get back to the shop to make sure I did.

I checked out GT98 in Mame and yes it has some basic tests.  Not as good as my dead Tetris board.  :`(

[SirPeale]

Bumping this as I'm going to go back to it soon.  I did plug it in the other day, and I can say it' sure looks like it's outputting inverse color: white is black, red is green.

[lilshawn]

Bumping this as I'm going to go back to it soon.  I did plug it in the other day, and I can say it' sure looks like it's outputting inverse color: white is black, red is green.

 



the world has gone crazy!!!!

[SirPeale]

The only thing I can think of is that something's wrong with IC1. 

I also wish my test bench had easy access to a color bar test.  I miss my Tetris board.

[Kevin Mullins]

The only thing I can think of is that something's wrong with IC1. 

If I recall correctly you could get the pinout for IC1 and check each output for voltage.
So disconnect say the blue input and see if the voltage loss on that particular output also goes away. (same for red, green)

OH.... another thing I had come across one time on a previously worked on chassis was one of the small four wire ribbon cables plugged in backwards. The blue/white wire cables from the chassis to the neckboard and such.
I forget now exactly what it was doing, but it was weird/missing/wrong color issues for sure.

[SirPeale]

Hey, that backward cables thing has me thinking.  I'll definitely check it out when I get there next.  I doubt that's it, but it's something to check.

Weird thing is when I was attempting to adjust the monitor at one point the colors snapped back to where they're supposed to be.   I kept adjusting it and they went back out, however.