Hi guys, First post here and relative newcomer to console restoration/repair, so please go easy on me if, at any point, I exhibit ignorance or ineptitude. I want to learn and would like your help! That being said, I recently acquired a Nintendo 64 as a gift and was told that it was fully functional. I had no reason to believe this person would be lying to me, but I (stupidly) did not test this before opening it up for a little clean-up, so there's that. In any event, after disassembling the unit, cleaning and thoroughly drying the plastic pieces, using compressed air to clean up the electronics a bit, and carefully reassembling, I plug everything in and get...nothing. The LED does not light up, absolutely no indication of functionality whatsoever. I disassemble the unit again and see nothing that stood out as broken or in any way out of the ordinary. The power input module seems soldered to the board solidly, the POWER switch seems to be functional...all seems in perfect order. I secured the shielded board back into the bottom of the plastic shell, but do not attach the top portion yet. I insert the Jumper Pak and a game and connect the AC Adapter and AV cable, as well as a controller. It turns on! Everything seems to work great! The story doesn't end there, unfortunately. I reattach the top part of the plastic shell and secure it with its screws, plug everything back in and...nothing again! I remove the top plastic shell once more and try to do everything as I had done it before, but it didn't work this time. Purchased a new (third party) AC Adapter today and plugged it up, but got nothing, so it doesn't appear to be related to that. I disassembled everything again and stripped down to only the bare board. I installed the Jumper Pak, a game cartridge, controller, (original) AC Adapter and AV cable. It turns on! I turn it off and back on again, just to see if it is some kind of fluke. Nope, it works. After reassembling once again, it's back to not working, either in partial or complete reassembled forms. I'm about at my wits' end! I suspect it's something to do with the power input not making a proper connection to the AC Adapter, but I can't be sure. Anyone have any ideas? Seen anything like this with an N64? Any helpful advice would be appreciated!
I know you said you dried the shells, but make sure there isn't water still inside the posts where the screws go into. It could be that when you put the shell back on and tightened it up some water seeped out and created a short. Similar thing happened to me once with a super nintendo, and I finally realized that the shell wasn't as dry as i thought it was. Use some compressed air and blast it into the screw posts.
Also check how you've reassembled the shielding/heatsink. The N64 has a lot of metal plates that could be shorting something out. I'm particularly careful of that little RF shielding plate around the jumper pack.
I think you may be on to something. Since my OP, I have done some additional testing and have found that, when I have NOT inserted the Jumper Pak into its port and turned it on (after resetting the AC Adapter by leaving it unplugged from the wall, of course), the LED turns on each time. So...I'm relatively certain that it's related to the Jumper Pak or the port it inserts into or the shielding around it, as you mentioned. I thought I had reassembled that correctly, but perhaps not. I'll take a closer look at it. Any hints with regard to how that is supposed to install, when done properly? EDIT: That seems to have been what it was. I disassembled everything again and paid very close attention to the metal well and ground pieces around the Jumper Pak port, making sure that they were in their tight, proper positioning. After reassembling everything completely and installing the Jumper Pak, everything seems to be working properly! I am currently playing Super Mario 64! Hopefully, it all stays working that way.
Glad that my thoughts helped. You probably had a short between voltage and ground. You're lucky to have a power adapter with auto-reseting fuses. Most (if not all) of mine have simple one time trip fuses.
