John's Arcade Forum - Classic Arcade and Pinball Collecting and Restoring Discussion Forum - RETRO MAME - Nintendo Vs Forum

My asteroids has been acting up.
Sometimes it works great, sometimes 1/2 a screen - a smack to the side of the cab fixes that - sometimes a bright dot in the center with faint lines going to all the asteroids.

I would like to reflow all the joints first. The smack fix gives me the notion it is a poor connection somewhere.

I seem to remember though, standard discharge tool = bad??
Is there a special tool/technique required to discharge the vector. XY monitor? 

I checked youtube and all the available vids are grounded screwdrivers under the cup.

Advice please.



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i would check the deflection transistors and generally everything for cold solder joints, maybe reflow everything.

as far as the tool goes, you want to discharge the monitor slowly, just add some 1megaohm resistors in series with the alligator clip of your 'discharge tool'

Hey Ian, yes a total reflow is first on my list.
As for the tool modification, do you have a picture of what I need to make? I don't quite understand and want to make sure I get it right so I don't kill the monitor (or myself).

My understanding of caps, transistors and resistors is limited to watching John change em in his videos. 

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are you using a screwdriver with a wire and alligator clip on the end?

Yes! Thats exactly it. It was a wrist strap but I cut the wire and attached it to the nail-puller screwdriver. 

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so what you need to do is disconnect that wire from the screw driver, and add a 1 megaohm resistor to the end of the wire and attach it back to the screw driver


so Alligator clip->wire->resistor->wire->screw driver

I am on it Ian! 
I will post a pic before I do anything.

Thanks a bunch!

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