Hi there, wrapping up a restoration of a High Speed. As part of that I replaced many of the components listed in the System 11 Bulletproofing guide (https://pinside.com/pinball/forum/topic/williams-system-11-bullet-proofing-thread), including all the capacitors on the power supply board using this kit from Yorktown: https://yorktown-parts-equipment.myshopify.com/products/pinball-power-supply-rebuild-repair-capacitor-kit-bally-williams-system-7-11a. However, I did not replace all the resistors and diodes in the high voltage section.

After putting the system together, it posted a few times, then stopped. I bench tested the CPU board with an external power supply and got a 0 on the display. So, I connected it up with a Rottendog power supply board from one of my other tables and it boots and plays beautifully.

So, clearly something's wrong with the power supply board. I followed this testing guide:
https://homepinballrepair.com/troubleshooting-williams-system-11-ss-pinball-machines/

It gives suggested voltages for the low voltage side of things and all mine are within range. However, that guide does not give high voltage ranges. I (carefully) checked mine and the power supply board is putting out 104 volts. Is that within an acceptable range? The Rottendog board shows 100 almost exactly.

Is that the issue? What else should I test? Really appreciate any guidance!

The game does not boot, no code on the LED on the board. My understanding is this most often means a voltage out of range, no?

Hey all, sorry to be slow responding. I wanted to wait to test it out more before adding more here.

First of all, the table would not boot with the old power supply board. No LEDs at all on the CPU board, no startup tone, nothing -- but the GI lights would come on. With the Rottendog power supply board, it booted and played brilliantly.

Now, after reading your responses I swapped the original power supply board back in for testing, which I recently replaced capacitors as mentioned above, and... it worked. It worked just fine. No problems at all. Weird.

The next day I turned it on and, sure enough, still working fine. Tried it for a few days until yesterday it failed to boot again. And, again, no indicator LEDs at all on the CPU board, but the GI did come on.

Weirdly, as I was looking around in the backbox the GI lights flickered and the game booted! I immediately thought loose connector, but I gave everything a jiggle and nothing. Now again the game is booting up just fine.

I don't even know where to begin troubleshooting now... Again, appreciate any advice.

Thank you, I'll give this a shot!

Went through and reflowed everything and everything looks to be working perfectly after a week or so. Many thanks slochar!