right, Its powered up and doing exactly what I remember it doing which is all of the coils (except flippers) going crazy, lights flashing and the score displays flashing up random crap shown in this video.
Apparently this is what happens when there's a reset issue with the CPU.
Reading online someone said the first thing to check is the voltages, to make sure the board is getting what it expects. So DMM at the ready, but there are no test points on the board to check the voltages so I've look at the schematic (
http://mirror2.ipdb.org/files/1590/...l_page_28_blank_with_paginated_schematics.pdf Page 35 and 36) and it looks like I should be getting the logic power and logic Ground going to J10 of the main board.
Physically this is obvious as it comes straight from the power supply to the board. So I unplugged from the board to measure the voltage across the two pins that the voltage should be coming in on. But getting nothing.
connected it back up and turned it back on, expecting it to go crazy again but getting no life at all now.
So, I'm guessing there is a problem with the power somewhere. I can sort of work out whats going on with the power coming in, but only sort of, and I don't want to kill myself, so I thought I should check before I go poking around in anything I don't get yet.
The White cable going to the step down transformer at the front is mains from the socket. Getting 240V on that and getting 118V on the output of that transformer that goes to the transformer board at the back of the cabinet.
The black wire connects to the Transfomer board at the back through this EMI Filter. Getting 118V on both sides of that.
But then I get a bit lost. It looks like the load side of the EMI filter go to the connector block underneath it,
The front of which has wires connected that look like they go down towards the front of the cab (power switch, service socket etc) which makes sense as the voltage up to that point is present whether the machine is switched on or off at the front, as long as it is plugged into the mains.
But I dont know where to check next to see whats going wrong.
I've measured the voltage on those 2 big caps at the back. Getting 11.88v on the Grey one at the back, but nothing on the front one. I think this one is supposed to be the 5v one, which would explain the board getting nothing as well, but where does the voltage go from 118v ac to 5v dc and will there be anything that I can check or replace to try and fix it?