Quoted from Dewman:Not a lot of love for the Kahr board on the forum, but after repairing several driver boards, new Z connectors, and even trying brand new boards in my TZ I still got resets. Not one single reset since I put in the Kahr board. So I have no problem saying go ahead and use one if you want to.
So I disagree with the 'no love' comment - when pin sound copied my product the outpouring of support expressed in the forums sure felt like love and I still appreciate it. In Nicolas I lost somebody who I thought was a friend but I was reminded of the many, many others I've accumulated through pinball.
A little history on the ezSBC PSU5 - Daniel created it because I asked him to do it. I've had a long, productive business relationship with him and he still does all the surface mount work for my daughterboard here in the USA (in Arizona) (the copycats are just selling crap they have assembled in cheap chinese fab shops). Here's a thread from six years ago where I called out the PSU5 here on Pinside: https://pinside.com/pinball/forum/topic/lm323-replacement-released-at-ezsbccom. He also does the surface mount assembly for my Skee Ball Display boards.
The PSU5 is great because it eliminates the heat burn-off in the linear regulator, but installing one doesn't re-balance the electrical loads - the only way to rebalance 5v consumption across the available supplies is to install my daughterboard. I walked through this in detail on the stage at the Northwest show in 2018 but unfortunately the video of that presentation no longer exists. The short version of my explanation centered around the usable life span of the power supply - specifically the MPU under voltage sensor drives power supply repair to happen more frequently than would otherwise be needed.
Still short, but not quite as short version follows (skip to the end if you don't care): Components tend to degrade as they age - the caps, the bridges, the headers & pins, the solder joints, etc. Borrowed from my Tacoma presentation, here's a representation for how a electrolytic cap can degrade over time: representation of component degradation
The power supply is a system assembled of such components and thus degrades over time as well - sort of like a summation of the degradation curves for all the individual parts. The under voltage sensor triggers (i.e., causes a reset) when the power supply system briefly cannot deliver sufficient energy. Move the MPU off the "goes everywhere" 5v line and you can take advantage of significant additional lifespan from the now "goes everywhere except the MPU" power supply.
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The soldering iron can remain cradled until you approach the second green line. When is that? Check for the flashing red indication on the Pro version of the daughterboard. The chinese-made copycats didn't copy that capability.
More of my discussions from a couple years ago were in a thread similar to this one: https://pinside.com/pinball/forum/topic/kahr-daughterboard-question-is-it-a-permanent-fix#post-4324443 .
-Rob
-visit https://www.kahr.us to get my daughterboard that helps fix WPC resets or my Pinball 2000 H+V Video Sync Combiner kit