Describe this behavior to me... give me some hints as to what would cause it?

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Describe this behavior to me... give me some hints as to what would cause it?

I have re-tubed a G07, converged very well. The picture looks great. The chassis is newly capped w/new flyback, HOT and regulator...

Here is what happens... (the game is Gorf)

#1 After the mother ship is destroyed the screen flashes blue (like its supposed to)... but when it flashes it kind of goes ape-shit.. sort of collapses/warps instantaneously while its flashing.

#2 Also when I compete the first wave, and the screen goes blank, I see raster lines for a blip of time... but when the next wave stars its clean as a whistle...

I think I may be dealing with 2 things here... #1 I think is definitely a monitor issue #2 maybe not...

Thanks for your input
 
The B+ supply is sagging under the increased current draw. What's happening is that bright flashing screen draws a lot more current from the monitor's power supply than normal, causing the B+ voltage to drop. If you hook a meter up to it and watch, I'll bet it jumps all over. You're never going to get it perfect - that screen of Gorf is going to cause the picture to change size regardless - the DC restoration on arcade monitors isn't perfect. But if you're losing sync, then something is wrong with the monitor.

My best guess - change the B+ filter cap. That's the great big one on the chassis. Put in a somewhat larger value if you can.

-Ian
 
The B+ supply is sagging under the increased current draw. What's happening is that bright flashing screen draws a lot more current from the monitor's power supply than normal, causing the B+ voltage to drop. If you hook a meter up to it and watch, I'll bet it jumps all over. You're never going to get it perfect - that screen of Gorf is going to cause the picture to change size regardless - the DC restoration on arcade monitors isn't perfect. But if you're losing sync, then something is wrong with the monitor.

My best guess - change the B+ filter cap. That's the great big one on the chassis. Put in a somewhat larger value if you can.

-Ian

That makes sense... I bought this chassis of someone recently it was totally rebuilt EXCEPT the B+ filter cap. I have a new one, I will replace it.
 
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