Hi Itsu Thats right xtal as per the above diagram, there is an unfortunate error in the pcb, with one of the pics pin was connected to pin1, cut that accidental track underneath on the pic that has this error, then you will notice underneath the board there is a way to solder surface mounted caps to earth across pin 2 & 3 of each pic, they are not connected to ground or should not be, if you look at the track layout.
Then you will need to find a way of soldering a 20MHz xtal onto pins 2 & 3 you could solder directly on to the chip pins so the xtal sits on top of the pic, or you could solder underneath the pcb but make sure the metal case does not touch anything and short it.
Then you will need to re-burn the software with the configuration bits set for HS which is how it was before we got it currently going.
I don't remember being able to get the high current spike with the pic running at 4mhz like you have at the moment.
Unfortunately i cannot guarantee you will find the pulse, this pcb setup has never been checked as working by me, but my intention was to give it a go to try and make it easier, when i got the current spike i kept the current low by limiting the whitenoise pulse width to 100nS by feeding 2 digital monostables, It's the clashing of the rising or falling edges occasionally that seems to create the spike but i could never track it exactly down which is why i use whitenoise because it covers every random pattern once in a while creating the spike.
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