N64 with garbled sound, graphics and freezing

[VashTS]

Just got a lovely ice blue console but sadly won't boot properly.

I have multiple known good carts, new video cables, working psu, new 3rd party jumper pak, an expansion pack.

When I first got it it barely booted Mario 64 and if it did, it played the wrong sound effects. Cool, I figured easy fix, probably a dirty cart connection.

I cleaned everything thoroughly, inside and out. Took the cart connector completely off and cleaned precisely.

Reassembled and nothing so I ran and got the new jumper pak and video cables to no avail.

I figured it's the expansion pack but I have the same symptoms with the jumper or expansion. If I take out and reinsert the jumper/expansion it sometimes boots and freezes or boots to garbled graphics and sounds.

I heated up the board, mainly around the expansion pak connector to no avail or change in behavior.

Anyone got any clues what is wrong with this console? I'm almost 100% sure it's RAM related but any troubleshooting tips would be welcomed!

 

[VashTS]

well i'll be damned. i got the system to boot and playable in super mario 64, albeit with no sound effects.

it wasn't freezing as i ran around outside the castle so i just let it sit for about an hour at idle.

rebooted and it works fine now. multiple games tested working fine (banjo, glover and mario 64 is all i got). over two days now, its working. wild stuff.

the expansion pak i think is the culprit here. i swapped out to the jumper pak and im leaving it as is. i still have the expansion pak and can test on another system down the road perhaps.

such weird behavior, but it seemed like the ram just wasn't flushing properly. leaving it running for that hour seemed to have filled it or at least cycled out what was it in there previously and now that its clean, it works. just my theory.

 

[VashTS]

........and a week later, i turn on super mario 64. attempt to enter whomps fortress and a garbled sound effect happens.

freezes on the star select menu! reboot and freezes when i ground pound. loaded a copy of glover, freezes

it has to be the RAM. i guess i have to get a new mobo and swap it in.

 

[Oldyz]

it could be the cartridge contact "comb"

the best way to test for this is to play a game & move the game while the game is running , if you get lots of corruption the comb is very loose & probably has patina.

i fixed my own N64 "comb" years ago by dissasembling the console & bending every "tooth" very slightly to make suer it grips the cartridge better - broke some of the teeth in the process and recreated some of them using old PC parts & a dremel tool -
so if you try to manually mod the comb , my advice is to purchase a new one before attempting a mod

another case is that the soldering has mini cracks around the sound chip are, or where the AV outs make contacts on the main card, so resoldering might be needed