Galaga cab G07 monitor suddenly went out save for a red dot

rhistr

Member
Joined
Oct 18, 2024
Messages
68
Reaction score
49
My galaga machine's monitor, while playing, just went out save for a cloudy red dot in the upper part of the screen. The game is still playing in the background but I can't see it. Here's a picture. It was working perfectly before and I even got the monitor chassis serviced recently. Any ideas what might be the issue? I'm way out of my league trying to diagnose it without any guidance...thanks for any help you can give!

IMG_0188.jpg
 
first step is including information regarding what monitor model it is. if you don't know, take pictures of the [largest] deflection board mounted on the bottom metal tray. not the TV tube labels, those have nothing to do with this.
 
Gotcha! So here are some pictures. I also asked the fellow who swapped the chassis out just a few months ago in case the pictures aren't enough, so when he answers I'll also add the answer: image0 (3).jpegimage1.jpegimage3.jpeg
 
Welcome to the G07 COB 904 or 907 malfunction study club ,there is allot of threads about these fuse eaters .ill be watching this thread to learn hopefully
 
Can I ask what was wrong with the former chassis a few mos ago?

Flyback looks ok from pics, as do caps.
 
Can I ask what was wrong with the former chassis a few mos ago?

Flyback looks ok from pics, as do caps.

It was an issue with brightness and colors...the whole thing had grown dim and green. Once the repairman swapped out the chassis, it looked bright, colorful, great with no noticeable issues up until yesterday. He did mention that the tube itself seemed fine.
 
Any ideas on what the issue could be? Is it something that's for sure on the monitor side, or could it be something else? If it's for the sure the monitor, I have someone an hour-half away who might look at it. But I don't want to bother him if it isn't a monitor issue.
 
Any ideas on what the issue could be? Is it something that's for sure on the monitor side, or could it be something else? If it's for the sure the monitor, I have someone an hour-half away who might look at it. But I don't want to bother him if it isn't a monitor issue.
Here is the typical terminology so you don't confuse yourself or anyone else:

Chassis = The board sitting under the tube. (ie G07)
Tube = The glass tube with the screen
Frame = The metal that holds the chassis and tube together.
Monitor = Chassis + Tube + Frame

I'm way out of my league

Without knowing what you are doing, then you don't even know where to start. There is nothing wrong with this but it's going to make it very hard for you to figure this out without spare parts to swap in.

You need to start do a process of elimination.

You either (or all) of the following to help narrow this down.

  • Tube rejuvenator/tester
  • Known-working spare chassis
  • Known-working spare tube
Unless someone here wants to confirm that your tube is 100% working then you need to ether buy (and swap-in) and known working chassis. But I'm not going to die on the hill and say your tube is 100% working.

The other option is to send the chassis out to someone like @paul400 and he can service it for you. But the gamble there is that there isn't anything wrong with your chassis and the problem is actually your tube.

Then you have spent time and money getting your chassis fixed but the problem is actually your tube.

Where are you located? Maybe someone nearby could test your tube for you and then at least you could be sure the problem is your chassis.

Again, there are other things you could start testing on the chassis but it would require a multimeter and some confidence that you know what you are doing. Plus help from G07 experts on here.
 
let's try something simple. unlatch the control panel, unplug it, set it to the side. then take off the glass and set it in a safe place. turn the game on. touch the face of the tube. if there's no static, the monitor isn't working.

try this, report back
 
While you are learning how to diagnose this problem, do not leave it on for extended periods. Do the check you need quickly and turn if off again.

If it is working with no deflection it will end up burning the tube phosphor where the dot is hitting it.
 
Back
Top Bottom