U5000 help, was all red, now too much green

tevans333

New member
Joined
Jun 17, 2009
Messages
216
Reaction score
0
Location
Bloomfield, Michigan
I just purchased a game with a U5000 monitor in it. It was displaying all red when I bought it. I have heard that the transistors on the neck board overheat and are a common problem. When I took a look, sure enough the pads on the middle one were completly black and the pads lifted. It already had jumper wires attached though. Looking at the other two transistors the pads were also lifted, but didn't show the same signs of heat damage and didn't have jumpers. I went ahead and added jumpers and touched up any suspect looking solder joints. Now it has way too much green. Although the picutre doesn't show it, there is blue and red but it is just over powered by the green. There are also some horizontal lines across the screen

The first three pictures were how I recieved it, the third is the picture after I added the jumpers and touched it up. Any ideas? Should I replace the transistors as a starting point, along with a cap kit?

It also looks like there was some high temperatures on the chassis as well, I can try to get some pictures soon.
 

Attachments

  • Copy of CIMG9899.jpg
    Copy of CIMG9899.jpg
    99 KB · Views: 22
  • Copy of IMG_1131.jpg
    Copy of IMG_1131.jpg
    96 KB · Views: 23
  • IMG_1133.jpg
    IMG_1133.jpg
    97.3 KB · Views: 24
  • Copy of IMG_1136.jpg
    Copy of IMG_1136.jpg
    101 KB · Views: 25
Last edited:
some pretty ugly jumper work there. lol looks like the neckboard off one of my U5000s. I wound up replacing it with another neckboard.

but your situation... looks like your color drives/biases are out of whack. if you crack open the K7500 manual (it's functionally the same as the U5000, minus the resolution switching capability) there's a section in there about white balancing that will help you here.

start by turning all the biases down though, does this eliminate the retrace lines? you should have a picture that's "complete" but minimally saturated.

I'm going with this NOT being a tube issue because you didn't have green+retrace lines before working on it.

you can alternatively turn down the flyback Screen, just give it a very subtle turn down. try these and report back.
 
yeah, they don't fit on very tight. they just kind of slide on. I wanna say a user on here replaced their heatsinks on the same kind of neckboard once, but I don't know where you'd find such replacements or if they scalped them off something else.

I was going to make a suggestion about adding thermal paste, but realistically how can you do that if it slides on? lol

you might be able to squeeze the clip with needlenose pliers to make it tighter, I forget what they look like exactly.

btw, were you able to adjust that green tint out yet?
 
The green tint appears to be the green gun turned all of the way up. The reason I say this is the green retrace lines only appear when this happens. The cause could be a short on the board or an internal short in the tube. Since you worked on the chassis it is the more likely culprit. Check all components in the green circuit, and look for any possible shorts between components that could cause the overdriven condition.
 
The green tint appears to be the green gun turned all of the way up. The reason I say this is the green retrace lines only appear when this happens. The cause could be a short on the board or an internal short in the tube. Since you worked on the chassis it is the more likely culprit. Check all components in the green circuit, and look for any possible shorts between components that could cause the overdriven condition.

There was a short on the green transistor. All 3 of the pads are lifted and gave it enough wiggle room to short out on the heat sink. I fixed that and it help somewhat, I then turned down the green pot and BAM! it looks great:) I just need to degause the upper left corner, if only I had a degauser:( I tried a drill and soldering iron, but neither helped.
 

Attachments

  • IMG_1150.jpg
    IMG_1150.jpg
    103.4 KB · Views: 16
Back
Top Bottom