WG6100 w/Tempest Showing a Tangled Mess in the Bottom Right Quadrant

So this is basically the second part of a previous post about a tempest that lost deflection.

After running for a while that Tempest’s display changed into something that can only be described as a tangled mess:

Tempest Tangle Edition
Tempest Tangle

That is something that I never had seen before.  The owner turned the game off and back on again later that day and it was working normally.  Then it would get screwed up again.

Continue reading “WG6100 w/Tempest Showing a Tangled Mess in the Bottom Right Quadrant”

WG6100 w/Tempest Showing a Multicolored spot in Center of Screen

So I was helping a newly minted arcade game owner when his first purchase, which is his favorite arcade game: Tempest.  Shortly after getting it the X-Size pot fell apart and the game ended up only showing a Multicolored spot (larger than a just a “dot”) which changed depending on what the game was doing.  We soldered in a larger replacement (dangling from some wires) but while this did change the display a little when the pot was articulated, it did not fix the problem.

He had joined a FB arcade repair group and asked for help there and ended up with ideas ranging from his brightness being too high (it was not – I think the person that responded thought the game was drawing normally but with retrace lines and a white dot in the middle, kind of like how it looks when you’re drawing on an oscilloscope with no Z input), voltages too low (they were not), and one even going down the path of impending AR-II failure(!) and going on about replacing leaky sense resistors and the bottlecap transistor.  Oy vey!

Continue reading “WG6100 w/Tempest Showing a Multicolored spot in Center of Screen”

How a Screen Full of Garbage can be a Diagnostic Indicator

(This is essentially a copy of something I posted in a Facebook arcade repair group not too long ago.)

I was replying to a post that had to do with a game that was showing garbage on screen but was otherwise not working. The type of garbage you see on screen can actually be a good diagnostic indicator. At least, it is a better diagnostic indicator than nothing on screen at all. Continue reading “How a Screen Full of Garbage can be a Diagnostic Indicator”

Lithium Battery Replacement for Williams and other CMOS Systems

So you have decided to reduce the risk of battery leakage damaging your precious Williams arcade or pinball board by replacing the existing AA batteries with a lithium (CR2032) replacement.  Great!  Lithium batteries like the CR2032 tend to leak much less than alkaline batteries so this is a good generally a good idea.

Note that I said much less than alkaline batteries – lithium batteries can still leak causing damage to your PCB!
You need to maintain them like any other battery system.

So now the question is, how long will the lithium battery last before it needs to be replaced?  I would suggest that you replace the battery as soon as it voltage-under-load drops to 2.8v.  Why 2.8?  Two good reasons.  First, here is a discharge graph pulled from the Energizer CR2032 datasheet: Continue reading “Lithium Battery Replacement for Williams and other CMOS Systems”