Cleaned up my Xenon the other day, including vacuuming out the cab. It has been flawless for over 5 years, now the machine won't boot, the sound board puts out a howl, and the displays flicker very weak.

Xenon has the power module/ rectifier board in the lower cabinet.

My high voltage DC circuit @ test point 2 is only putting out 152 volts instead of the 220 it is supposed to.
All other test points are good.

I have done the following:

- Checked and cleaned the F2 fuse and fuse holder. I have 0 resistance across the fuse solder joints, so both are good. Also checked the other fuses and test good.
- Tested the 4 Diodes and the resistor, test good. This circuit uses didoes instead of a bridge rectifier
- Tested continuity from both input pins on J5 to the single output pin on J4, multimeter shows 650 and 625 with the diode test, this is close to the individual tests on each of the diode (not sure what that means other than there is a drop in power)
- Visually inspected the transformer and wiring and cannot see anything. The two red input wires are from the input side of the transformer/power line. Can I test these before plugging back in to the power board? Where do I ground them to get a good AC reading?

I am at a loss for what to do at this point. I assume the issue is the high voltage circuit, but any suggestions or help is appreciated.

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I hear ya. Was focused on that board since I hadn't opened the head until after it went bad and the PinWiki steps and it suggested getting the rectifier board working 100% before moving on. I'll skip it for now.

Should have mentioned it's an Alltek MPU board.

I get no flashing on the MPU. Solid Self test light and Solid 5v light. Manual suggest checking 45V if the light is solid, but it checked fine.

The test Points on the MPU are good except for TP5 - VMA, I get 0. This is Valid Memory Address?

On the Solenoid board, I have 12 v and just over 4 v at the test points.

The speaker was a loud low humming, not a howl.

MPU test points are good
Solenoid test points are good (well 4v like noted earlier). Tested this as the only board plugged in and with all boards plugged in.
I Disconnected the sound board a long time ago
No flashes at all, just solid green LEDs on MPU

Thanks for the link, I've been looking for something like that.

OK it is 4.3V, but that makes sense.

This is my first bally work and I'm a little confused by the schematics. (williams diagrams of the time are way easier to understand)

The un regulated 5V on the power board is tested at TP 3 @ 12v. It is Pin 10 on connector J3 on the power board. If that corresponds to pin 10 J3 on the Solenoid board, then those connections look good and tight. I'll test it on that end next.

Ok I cleaned the # 10 pin of J3 on the solenoid board for the 12v input. It is now working. Didn’t notice anything before but it was a little corroded/burnt and none of the others were.

It’ll need repined but works for now. Thx for all the advice.