Galaga video is all blue with vertical white stripes

spookyblue

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Galaga video is all blue with vertical white stripes

Been lurking here for...ever, really. I'm not very experienced with the extremely technical stuff (basically beyond cleaning contacts and replacing fuses), so hopefully I can explain myself in a useful manner.

This is an all-original, full-size Galaga, purchased in November. It worked, but with scrambled video, so I took it to a shop that I really like. My tech replaced the bad video ROMs, installed a monitor cap kit, and replaced the original power supply with a new switching supply. He does excellent work, and I trust him. Everything looked great, and I gave it to my wife for Christmas. We play it every day and turn it off every night.

* The issue:
Today I turned it on and noticed an unfamiliar, faint, high-pitched whine. It went through self-test and played the 'ready' explosion. But the monitor is a bright blue without any graphics. It will accept credits and seems to play normally, just nothing on the monitor except this blue screen.

* Adjusting the monitor:
I tried adjusting the brightness/contrast. No discernible change. Adjusting the cutoff also does nothing. I would think that at the very least, I could brighten or dim the monitor, but the trim pots don't seem to have any effect at all.

* Removing PCB:
Next, I unplugged harnesses and removed the PCB. The edge connector contacts look fine to me...nice and shiny. I don't have a chip puller (yet), and I'm hesitant to start popping chips and cleaning posts just yet. I put the board back and powered on again; no change, not that I really expected one since I didn't actually do anything but do a visual inspection.

* In conclusion:
My tech guy warranties his work, and I can take it back to him, but I thought perhaps someone who is familiar with these dinosaurs might have an idea. I don't think it's going to be some simple adjustment, but I figured it would be worth a shot to ask.

I've learned never to underestimate the collective power of a bunch of geeks. My own geek-dom extends into a different realm (software), and I'm just a trainee with respect to the hardware world.

Thanks in advance, and thanks to everyone who has posted helpful info here. You helped me to get my Asteroids Deluxe up and running, and someday even that pile of Battlezone in my garage. (Sort of looks like R2D2 threw up)

Best,
Spookyblue
 
Sounds like the monitor may have lost a cap or two. Did you have the monitor serviced as well? New cap kit etc?

Do you have any other Raster games you can swap a monitor with to check?

I'm still new to Galaga issues, so I can't say 100% that it's not a board problem, but it doesn't sound like it is. But it coins up and plays so that's a good sign.

Most high pitched whines come from a fly back that is going, or it's lost sync. Which could be caused by a cap going bad.

If you can post some pics of the screen, and the back of the monitor if you are unsure of what monitor chassis you are dealing with.
 
Recalcitrant Galaga

Sounds like the monitor may have lost a cap or two. Did you have the monitor serviced as well? New cap kit etc?

According to the person who serviced it, yes. The monitor was originally a little dim. In addition to the cap kit, he performed another service, the name of which I can't recall. I want to say "rehab". Maybe he degaussed it. I'll call him on Monday.

Do you have any other Raster games you can swap a monitor with to check?

Yes, a Tron. However, it's downstairs and this is upstairs.

Most high pitched whines come from a fly back that is going, or it's lost sync. Which could be caused by a cap going bad.

The whine stops after the power-up self-test.

If you can post some pics of the screen, and the back of the monitor if you are unsure of what monitor chassis you are dealing with.

There is a sticker on the back of the monitor which reads, "Phillips ECG, Inc. MV A48ABK05X".

Photos are here... http://spookyblue.com/heap/galaga.htm

One other note: I hadn't appreciated just how filthy the interior of this box was until today. What is the best way to vacuum/clean the interior without building up a static charge? I've zapped PCBs in the past while vacuuming up dust. If I leave it plugged in (and turned off, of course), the grounding strap should protect the boards, shouldn't it?

Thanks!
Spook
 
According to the person who serviced it, yes. The monitor was originally a little dim. In addition to the cap kit, he performed another service, the name of which I can't recall. I want to say "rehab". Maybe he degaussed it. I'll call him on Monday.

A rejuvinate???

The whine stops after the power-up self-test.

I have 2 boardsets and they both do the same...

- Mike
 
Those are retrace lines you are seeing. It appears you have a problem in the monitor with a shorted transistor on the blue drive. Check the transistors on the neck board.

If you find one is shorted then you'll want him to check the CRT for shorts, especially if he recently rejuvenated it.

This thread should be in monitors, not general repair & help.

Galaga makes lots of strange noises while it does the self tests. It all depends on the board... hums, whines, squeals, etc until the kaboom is OK.
 
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First, turn the brightness down until the diagonal lines go away. then turn the blue pot(s) all the way down. if it stays blue, unplug the video connector. if it stays blue, remove the blue drive transistor. if it stays blue, your tube needs to be tested with a rejuvenator.

otherwise, if any of the above steps makes the blue go away, come back and tell us which....
 
can someone answer this:

One other note: I hadn't appreciated just how filthy the interior of this box was until today. What is the best way to vacuum/clean the interior without building up a static charge? I've zapped PCBs in the past while vacuuming up dust. If I leave it plugged in (and turned off, of course), the grounding strap should protect the boards, shouldn't it?

i'm curious myself.
-s
 
First, turn the brightness down until the diagonal lines go away. then turn the blue pot(s) all the way down. if it stays blue, unplug the video connector. if it stays blue, remove the blue drive transistor. if it stays blue, your tube needs to be tested with a rejuvenator.

Still blue, which makes me blue. And my wife, since it was her Christmas present. I didn't remove any transistors, though. I'm leaning more toward a short in the crt. It's nice how easily this particular monitor/tube assy comes out of the box. It's sitting in the car right now. Taking it back to my "guy" at lunch today.

Totally unrelated... Every time I stop by his shop, I have to tear myself away from the rows and stacks of games/bits/parts that would destroy my every paycheck for the next 20 years. There is this one box that draws my attention every time I walk through the door; a restored Tempest. It's just gorgeous, and I don't begrudge him one penny of the price tag for all the work he put into it. One of these days I'm going to walk in and it will be gone. I might just have to put it on layaway ... for the next 6 months. :)
 
Totally unrelated... Every time I stop by his shop, I have to tear myself away from the rows and stacks of games/bits/parts that would destroy my every paycheck for the next 20 years. There is this one box that draws my attention every time I walk through the door; a restored Tempest. It's just gorgeous, and I don't begrudge him one penny of the price tag for all the work he put into it. One of these days I'm going to walk in and it will be gone. I might just have to put it on layaway ... for the next 6 months. :)

Tempest is a great game........and you (might) be surprised at what it would take to walk out the door with it! :)

Edward
 
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