Planet Virtual Boy

Richard let me know that the FB+ is using a CR1225 battery. I picked one up today but I don't have the tools to open a VB cart. I purchased some precision mini pliers but they are to thick to fit. Tried some other stuff as well but I seem to be just causing damage to the screw.

I want to buy a gamebit off eBay but I am unsure what size the VB screws are. Are they 3.8mm?

I was thinking about modding a screw driver but I think it would be about the same price as a gamebit (under $4).

Anyways, I'm curious about what size the screw is and if anyone has any ideas on how to open it?

Thanks!

As I said on IRC, it is indeed 3.8mm. I've found that the cutting type of pliers can usually get the screws out. The pointy ends of the jaws fit in the little notches, and you can turn the screw if you're careful.

However, you might have further difficulties once you get it open. I don't know for sure, but I'm assuming the FB+ uses a button cell with solder tabs welded on, just like the official carts. If this is the case, your "off-the-shelf" cell can't be used directly, without some kind of mounting that can be soldered to the board. There might be a tutorial online about attaching standard batteries to a game cartridge. I would do a search on "Game Boy battery replacement" and the like. Of course, if yours is the kind with solder tabs, just ignore me

some good news for FB+ users. below is a response from richard.

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i'm looking at buying one of these: 3.8mm gamebit

i did buy that bit and a screwdriver for it. it cost me about $16 with shipping. i got it in less than a week. the bit is made of a cheaper metal, its not a sears craftsman quality but it does the job. i recommend the screwdriver as it took some minor torque to get the screw off.

replacing the battery was really simple, i just popped out the old one with a mini flat head screwdriver and then slide in the new one.

at first the rom flashed to the cart was still not saving. i reseated the battery and flashed a new rom, that one has been fine so far. i'm not yet 100% sure the problem was the original battery. the battery cage seems really tight so i don't think it was the seating of the original battery. only time will tell if it is something else, like a bad connection. the old battery was about two weeks old by the time i received the FB+, but it could have been sitting around. if the new one is holding a save 2 months from now i'll assume it was battery related.

anways, just wanted to post an update =).

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I missed this when you posted it, so... Really?! I didn't know they made holders that small. I might have to ask Richard where he bought them and see if I can get mine hands on some for all my Gameboy save batteries that have died...

I assume it's this style holder: http://www.sparkfun.com/products/7948 ? If so, you should make sure the copper pad underneath is clean... sometimes the copper oxidizes, causing bad contact. With those holders, the PCB itself is the bottom contact, rather than typical battery holders, which have metal contacts for + and -, which get soldered to the board.

DogP

I'm pretty sure I've discovered the problem. I recently bought some CR1225's in bulk and they were held down to the tray with clear tape.

This left a residue on the top (+) side of the battery, which seems to be enough to intermittently disconnect the power from the SRAM (and hence erase the game-save). I now clean them with acetone.

The battery holder from sparkfun is very similar. Only I use the surface mount version.

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Right, I thought of this a few minutes after I posted. I remember when I was looking for a battery holder to replace a battery in one of my Genesis games, I came up with those mostly. I seem to recall that someone who did those kind of replacements said that they had never found a plastic battery holder that was small enough to fit in a Gameboy cartridge.

That's good news for Flashboy+ owners about the batteries just being dirty. I wish cartridge manufactures had just used battery holders instead of soldering the battery on. I can't imagine it would have been that much more expensive.

I think they probably didn't want to use battery holders because then you could just replace the battery easily, meaning... you'd most likely spend time on the game you've already bought rather than buying whichever newer game(s) the same people who made that game made

a "I'm afraid of soldering so I guess I'll have to buy the re-make (if there is one)" situation

(also, if your battery was defective around the time they were still selling said game (but after the 30 day warranty) they would probably use the excuse of "we might mess up the soldering (and it takes time/effort) so just buy a new cartridge")

but thats just a theory, really

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the battery i took out has no residue on it at all, its clean as a whistle. the replacement was from radioshack in a 1 battery per pack display. it was stored in plastic, the outside of the plastic was glued to the cardboard display pack, and also does not have any residue on it at all.

in my case, this is not the explanation as to why the first battery stopped holding the save. i noticed with the first battery that the save was gone after different lengths of time. when i got the FB+ Richard had flashed a game and left a save on there. i tested but the save was not there, so that was a little more than a week of storage time. i flashed some stuff to it, had a save, and that save was there for at least a day. the next time i made a save it was gone in hours. the next time it didn't store the save. it looks like it was the battery, but i'm not 100% sure. i do not own a meter to test the battery but what i did do was connect a 3volt LED to the battery and it lights up bright as day. i'm pretty sure the LED could be pulling off the last of the charge, so that test really isn't conclusive.

when i first replaced the battery i had mario crash flashed there. after playing the save was still not saving. i then reseated the battery and flashed a new rom, that rom has had its save stored. so this problem could be a seating issue or the copper pad as dogp suggested.

the last game i flashed was wario on 4/3/11 and is still holding the save. i am not playing that much but i am checking every couple of days to see if it is still there.