The techy had the same thing happen with it not turning on but then it was okay. He thinks one of the 'switching spider chips' might be playing up. Hopefully it will hang in there a bit longer so I don't have to buy a replacement board. I'm replacing the diodes on the cabinet base and I'm in the process of repinning so I'll let you know how it progresses.
If it is a spider chip, you will have to find a replacement board (easy). The 5 second delay as the game boots is normal. The GI relay switches on and off and then the displays light up.