So, I just screwed my Famicom motherboard. ( A story )

I spent the last 6 hours messing around in Nintendo innards.

Well, I pretty much never break stuff up ( im rather careful ) but i may just have done it this time.

Here's the story.
I wanted to put my 1984 famicom PPU in a socket, in prevision to composite mod it in the future, but also to prepare myself to socket the PPU in my more valuable mint AV famicom.

No big deal, unsolder PPU, solder in socket, put back PPU.

Problem is unsoldering the PPU is Harder than i expected, despite using loads of flux and solder wick. Seems like i could not get the last bits of solder out no matter what. After like 2 hours of heating and a foot of solder wick + trying to gently pry with a Flathead screwdriver, i finally get the thing out undamaged. It was the first time i ever unsoldered such a large thing, did not like it one bit.

I clean up, looks like I scraped the varnish off a couple traces with the wick, but all traces test good, i dont see any shorts, no traces seem to be broken. I solder in the socket and put back PPU.

I do some last minute tests with multimeter, all looks good. No shorts between pins .

I power it up, I hear the music fine but the graphics are all garbled, See, This is Contra...

http://i.imgur.com/qVNAP.jpg
http://i.imgur.com/I9m9A.jpg


I double check if cart is well seated, I re-insert PPU in socket a couple times, recheck the work, All looks ok but the Garbled graphics do not change.

My next thought was: "OMG I FRIED THE PPU!! Must have suffered too much heat O_O "

When things like that happen i have a problem because i cannot sleep after, i need to find answers.

I happened to have a NES in my junk pile, got it in a junk lot i had bought long ago. I had fixed most stuff from that lot but the NES was beyond repair, the image would scroll backward instead of forward ( Sort of ) then jerk back in place after seemingly try to scroll the wrong way. Not much fun.
I always suspected its PPU was fukt as the rest of the system looked good.

I decided to unsolder this PPU too but changed my technique. I removed most of the solder with pump then took out my Heatgun. (Damn thats what i should have done first time )
After a quick preheat i blast that PPU and cleanly remove it with extraction tweezers. Whole process <10 min, no damage to motherboard. :triumphant:

I try this second PPU in the Famicom, expecting backward scrollling but... Still the garbled Graphics O_O ....
Now i fear both PPUs are fuckt... I still cant sleep...

I solder in socket in NES mobo but Damn, now i dont have a cartridge connector to test it... ( I had scavenged the connector long ago )

I open up a spare working NES (theres too many screws in these things), take the connector and insert it in the other mobo.

I insert the Famicom ppu, hook it up, IT WORKS!! O_O
No garbled graphics at all. I insert other PPU, it scrolls backward. ( At least now i know for sure the PPU was responsible for this. )

So i conclude the damage is on the famicom motherboard, however it all looks fine!! I cant see anything wrong and it worked before i removed the PPU.

OK, honestly there probably is a broken trace or a short somewhere that i did not see.

I clean it thoroughly with Super wash spray, air blast it in case there is a conductive debris somewhere, the damn thing still wont work.

At this point I probably need to remove the socket ( I really dont feel like doing that) and check every single trace and possible change a couple ceramic caps that i had heated maybe too much.

However I am tempted to call it a day and throw the board in my junk pile, along with the PPU that scrolls backward ( blasted thing)

All in all its not too bad, I started the day with a Working famicom and a NES that scrolls backward, I finish the day with a Working NES and a Famicom with garbled graphics. Amounts to the same thing, No?

*Opens beer*

Damn, l would like my famicom to be working still...

Cant sleep yet.
This damn thing will haunt me.

*Opens another beer*

*Writes down the whole thing On assembler forum.*

Oh well ,I think ill try to sleep now.

Hey btw if you ever know what can cause such garbled graphics, let me know. Im probably gonna try to fix it anyway...

 

ouch, sorry to hear about your troubles, hope you manage to find the damage....
personally when it comes to remove ics like the famicom ppu I use a de-soldering iron that has a pump built-in... it only heats around the pin and it's a very easy process to remove stuff, the end result is very very very nice and clean. You should invest in one too IMHO

 

Mate sorry to hear.

For myself I use a Hakko 808 de-soldering gun. Yea bit of an expense but makes doing jobs like this a breeze! Over the weekend I replaced all the capacitors in my Mega CD, bit of a yawn fest apart from the SMD cap's.

OT jolly interesting-
It was cheaper for me to buy the Hakko 808 from America with extra parts (2 different tips, spare filters and tube, cleaning pins) and a step down transformer than it was to buy JUST the gun from Australia ($350 vs $550).

 

Australia Tax does that...

 

lol yea. Gotta love Aussie Tax (well we started as a penal colony so what to expect, awesome at screwing each other over), 2 tax's on fuel? Yea why not. I work in the coal industry in a consultancy company. At the beginning of the year we were overloaded, then due to the strong Aussie dollar, China slowing down what was the gumbyment's awesome idea? Increase the tax on pulling coal out of the ground! Awesome, my work was on the news (tv and the paper) the other week for letting go 100 positions. There were 6 electrical drafters, now there is just 2 of us.

Don't get me started on Warhammer stuff...... (I looked at getting back into it and giving up the console repair thing) check out the price difference between the full paint set UK[$440au adjusted) vs Australia[$730au] for example, America pays similar to UK.

end rant

Sorry for OT.

 

Ah I know which company. When I have the money, I'm leaving this country for good. It's not an XBOX lover's country well and that everything is super expensive...

 

Do you think the el-cheapo Desoldering irons are worth it?

Like these for instance:
http://www.elexp.com/solder/060849.jpg

During my lunch break I may do a hit and run at the nearby electro-junk store to see if they have them. I actually have... yet another scrap NES board, i could practice desoldering PPUs on it with the desoldering Iron.

 

^ I use something like this: http://www.ebay.com/itm/30W-Electri...Electrical_Test_Equipment&hash=item3a768da89c

it's not automatic/hi-tech but for the odd rom/ic desoldering it's great! way better and easier than using wick

 

I use one of those too, does make unsoldering ICs and sockets so much easier.

 

I use the type with the bulb on top for desoldering NES pcb chips. Really wish I could afford something like the hakko, after awhile my thumb gets pretty tired of pumping that bulb lol, but it does work fine, just make sure to occasionally take the pump tube out to clean out lingering solder, I just jam a coathanger down a couple times and knock it out, replace tip, good to go for awhile

 

I went to the nearby electronic store and they had a desoldering iron for 10$. It look nearly identical to the one Keropi linked. Cant wait to try that

 

^ you will be amazed just put the correct tip so you heat the solder and not around it

 

Hmm, mine did not come with any accessories. The tip that is on does seem to be a bit large for those small solder spots. Its big enough to insert a toothpick. I just tried it, does work a bit better that the regular pump but it does not suck all the solder.

Maybe i need a smaller tip and/or add solder before i suck it up.

 

mine came with 2 tips.... maybe you can get some tips where you bought it?

 

Shame no one can clone or make replacement ppu chips.

 

It seems by the text on the packaging that it may have contained a "replacement tip" But it may have been lost, the packaging was a filmsy thing, and this was the only one they had...

Yeah, I am happy i did not hurt my PPU and with a bit of luck ill repair my mobo.

Also, Hopefully this guy will end up doing a replacement PPU. http://universalppu.com/

 

UPDATE:

I FIXED IT!!!

I unsoldered the socket. Turns out the unsoldering iron cleaned all the holes pretty well but there was still a small amout of solder left that prevented me from removing the socket. Used the heatgun to finish the job, that went pretty well but it ruined the socket.

I rechecked every traces and FINALLY found that one of the pads on the top side had lifted.

Only about 10% of the pad remained and to it was connected a tiny trace that went back to the cartridge connector. I would have thought it was enough to make connection but after resoldering a new socket, I tested with a multimeter and it did not connect.

Tested the famicom again and it still had the garbled graphics.

Jumped the trace with a wire and Bingo!! Fixed

 

Glad you fixed it.

Did it not occur to you to simply cut the PPUs legs to remove it and then remove the legs afterwards? Seems like an easier job. You may have wanted the PPU intact though I suppose.

 

I had read about this technique but i was not sure if it would leave enough pin length for proper socket insertion.
I figured i was better off trying to keep the PPU as intact as possible.

At this point im going to practice on one more Scrap NES board and then do it on my AV Famicom.

Seems the best technique with the tools i have is the desoldering iron followed by heatgun

 

The entire video bus runs through the cartridge connector. Most graphical corruption can be traced to it in some way as I've discovered on multiple occasions.