New to me Gravitar can't start a game

Good progress. Honestly, the fact that the AVG is original alone gives it a 95% chance of being dead, in my experience.

I have one original that is still working, and I feel like it should be encased in glass and put in a museum somewhere. They're always the first thing to be replaced if I get a dead board with one.
 
I'll be ordering the parts for the 6100 tomorrow along with the AVG. I'll report back once I get it swapped. I am sure I will have more questions about the XOUT and YOUT at that point anyway. Don't want to hurt the fresh rebuilt monitor!
 
...I will have more questions about the XOUT and YOUT at that point anyway. Don't want to hurt the fresh rebuilt monitor!

Absolutely. Leave the monitor's 15 pin Molex unplugged at least until you have the game playing blind. But since you have a scope, you can be even safer by using it as your test monitor and only reconnecting the monitor once you know you have good output. What kind of scope?
 
Its an old POS. I don't think I could use it to see the game like some will do. I know enough now though to not connect the monitor when I have voltage present on the outputs.
 
IMO, the scope doesn't need to have an XY mode in order to be useful. It's nice when you can display the image on the scope screen, but seeing the XY signals in time is good enough to verify that they're ok, once you get familiar with what they should look like, at least in a general sense.

You'll definitely need to look at them on the 6100 to make sure they're completely correct, but in terms of verifying they're safe enough to connect to the monitor, pretty much any scope will do.

I've been wanting to post pics of 'correct' and 'bad' signals somewhere for reference, as if the DACs are bad, or any of the amps after them, you can usually tell by the signals being either railed, lopsided, or otherwise not having the characteristic stairstep detail they normally have.

If you post pics we can definitely help you out, once you get to that point.
 
This ain't a bad example (for a digi scope). Shows X/Y trapazoids. Levels per channel. Time base. etc ... :cool:
Need a keen eye (and experience) to see the errors in X-T mode.

 
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That's pretty interesting to watch! I'll see what I can do once I get my parts. Thank you guys for the help!!
 
I got some of my parts in today. Didn't have much time but I did swap out the avg. The game starts and plays now! (Blind of course) while I had it on, I did a quick voltage check on x and y out. Voltage was .3-.8 VDC which seems much better than the high voltage I had before. Parts should be here in time for me to rebuild the monitor this weekend. Do you think it would be safe to plug into the monitor with the output voltages being down like they are now?
 
What is the status of the monitor? What, if anything, have you checked on it already?
(Voltages, transistors, etc). Are there any burned components, particularly on the lower left corner of the deflection board?

You should give things a once-over before firing it up, IMO, and potentially save yourself some headache. Going cowboy style with 6100's is not advised.

- Test all 6 frame transistors, with a DMM, using the diode function. See the color vector FAQ Appendix B if you need more details.

- Reflow the solder joints on all headers.

- Check ALL wiring for any broken wires. Particularly where the wires connect to the deflection board, as well as where they connect to the frame transistor sockets. They are very brittle, and love to break in those places. Always check this, any time you have your hands in the monitor, as they can break at the drop of a hat, and a broken wire will often nuke a lot of other stuff.

- You may also want to pull the HV cage, and give it a visual inspection. Make sure no components are burned, including the HV transformer. Reflow the header as well.
 
The monitor has a couple of burned up resistors is the LV section. I have the parts to rebuild the monitor completely. I was mainly wanting to know if you guys think once I get the monitor repaired, if it would be safe to connect to the game with the voltages currently being output on the x and y out.
 
I tried to boot it into test mode but I just get static from the speaker. Very strange.
My options are limited with the monitor being dead. I guess I'll get it going before I mess with the pcb any more.

Normal for Grav and Black Widow, sometimes switching into test while power up go away.. Even does it on my test bench, as well as the games.
 
Thanks to help from you guys......... It's alive!
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