ARG! Famicom busted! - grey screen, cleaned many times, new solder... still broken!

This thing is giving me a huge headache. I figured I just needed to clean the cart slot. No luck. So I REALLY cleaned the slot. Nope. So I looked up close and noticed a few pins weren't making contact as well as others, so I bent all of the pins inward (just a hair, of course) and then cleaned the slot again. NOPE.
So I dismantle the thing. I went over pretty much every solder point on the board... at least the ones I thought might be important - the entire PPU and the other big chip all of the small chips, and then the entire RF/PSU board.
Same crap. Nothing.

Grey screen with a "hummmmmmmmmm" over the speakers (or maybe a "buzz" if you're an insect connoisseur).

EVERY ONCE IN A WHILE I can get the grey screen to turn to a blue screen. OK. A couple times (I'm re-seating the cart and trying new things every time) I get a green one, or a red one, and ONCE (like 1/100) I got some garbled graphics. When I press on the motherboard (back of console open), it seems to make the "colors" (blue screen over grey) happen more often. This is why I did a quick reflow, then another reflow on most of the board.

ARG.

Tried two power supplies (not that I think it would matter) and I know my test setup at least works on my own personal main Fami. I gotta get this one going... no way I would trash it.

 

Oh, and though I mentioned the fact that my main Fami works, I should make it clear: I'm on the right channel. Works normally on this TV. PSU seems fine, etc etc. Tried a couple of PSUs for that matter (my main one is JP so it is made for 100v not 110 or whatever the hell we get over here on any given day)

 

can you show some pics of the defect?

 

Good chance you have either a dead CPU or PPU. I have an original Famicom which just displayed a black screen no matter what, and replacing the PPU fixed the issue.

 

I'll get a picture today.

And yeah, I was thinking that, too. Maybe just a new PPU will get it going.

 

ALRIGHT SO I LIED. I was going to post a picture but it didn't happen.

I do think, IMO, that a new PPU might fix this beast. And I have just the busted NES to salvage.

...


Same chip/pinout, right? Dur?

 

Dur.

 

Hi, my name is Alec - you might remember me from such statements as "I'll get a picture today".

Sorry. Haven't yet. I'll probably just throw a PPU at it and see if it sticks.

 

Use a socket.
How do you plan to remove the ppu?

 

Desoldering.


Swapped the ppu from a working NES into the family and not much has changed, except now I have a reliable green static instead of gray.
Hmm

Maybe the RF unit? I think I might try to wire up a temporary AV mod to try and bypass it. Maybe.

EDIT: (photo)

 

Highly doubt it, try replacing the CPU. If either the CPU or PPU have gone bad, the system will refuse to boot.

 

Desolder another pair of 40-pin chips?

My pleasure! I'll report back.

 

Dice = none.
Same poopey green screen.

If I wedge the cart in, just right, I can get a black screen or sometimes a bit of a garbled graphic pattern. Which would lead me to think the slot is at fault... but trust me, that sucker is CLEAN (and all pins evenly adjusted). And I went over it with the iron to take care of any theoretical cold solder joints, with no result.
Maybe I'll just replace the RAM and this and that, until it works?

Or maybe I should just hang it on the wall?

I realized I said "RF unit" the other day but I really meant the board that contains the RF and PSU. I know the RF adapter box thingamajig works great - everything is fine on my other Fami (which is on loan unfortunately).