Fixing mid-game Stern Spike reset issue

OP

Quoted from vireland:

Pretty sure the instructions clearly say to use a multimeter with alligator clips to check the baseline at the start and then be able to get the reading in real time to see what you're doing. I expanded the warning section to be VERY CLEAR now, and changed the recommendation to adjust .1v at a time then test instead of .2v at a time and test to address your concern.
It's not common knowledge. I got tired of the "my Spike machine reset mid-game" posts in random Spike game threads all over Pinside, so I made a single thread to address the problem and provide the solution. For all I know, some of these poor sods are shellshocked from GoT Prem and think the resets are "as designed".
As long as you're here, can you confirm that the software for the watchdog circuit has been adjusted to make these momentary-drop resets less frequent, and if that's been adjusted on all Spike software or just some of them? Leaving this important information about potentially safer and easier alternate fixes to the watchdog circuit itself in software that have happened or will happen to rumor and speculation is not super-customer-friendly.

OP

Quoted from vireland:

If the 48V is fine, or if adjusting it up a smidge doesn't help, you could always secure the leads to the +/- and monitor it live while you play that multiball to see if the extra load drops the output in real time. It may be a defective power supply that only fails under strong load.