Forums

Hi folks,

as the title suggests, would it be possible to support the SRAM (that holds the saves) while exchanging the battery? I thought about a second battery or something connected in parallel (thus not rising the voltage).

I have some carts still "living" on their first battery (namely Phantasy Star and Ys) and I'd like to keep some saves I've got.

I also wonder if the SRAM is powered by the system while the cartridge is in use? Or is it powered by the battery only (even when the cart is used)?

Thanks in advance for any information.

Solder in another battery in parallel and then remove the old battery. They really don't like being in parallel.
I've done it few times and it has worked, though best option is to dump the saves, change battery and write saves back but this needs some more special hardware.

I thought there was some hardware to power the SRAM from the console while connected, which would also deal with safely switching between the two - and hooking it up to a stable 5V+GND seems safer than the parallel battery thing.

@TmEE
So hooking up a battery during exchange would be possible.

Then I'd hook it up directly to the chip (or somwhere else possible) to avoid accidentally desoldering both batteries during exchange. After that I'd provide the new battery and desolder the "bridge-battery".

As I don't have any device for dumping saves (and for just two games with batteries right now) this is not really an option.

@Maxim
I'll check the board for 5V traces to the RAM once I get one of those gamebits.

Anyone got any further experience regarding this method?

Thanks so far for the info.

When cart is plugged in the SRAM will get 5V and you can do the exchange then aswell, but I would advise disconnect the iron from wall when doing the soldering as I have had shorts because of grounding and lost SRAM contents due to it.

@TmEE
Very useful info, thanks! So heat up (maybe to a slightly higher temperature), unplug, solder, repeat...

Then I'll buy a 50-Pin connector and wire up the 5V/GND pins. Should be a lot safer than anything else.

Rather stick the cart into a working machine, or grab 5V from elsewhere and wire to some power supply bypass cap on the board.
50pin connector is a bit overkill

Yeah, I thought kinda the same way right after posting. But I like to handle my carts with care, they're precious (^-^)

In fact, one thing I thought of (before posting here) was: "Just stick it into the machine and do it." Maybe I even load the game just in case something goes wrong with the SRAM. But I somehow don't like the idea of soldering like that.

So I'm going to look for a nice spot to hook up either a second battery or 5v.

Thanks for all the information, it really helped a lot!

With doing it inside the machine you got one potential failsafe : The you can save ingame, which can fix any potential corruption that can occur.

Yeah, you see, I also thought about loading the saved game so I can save it back later.

And there's no chance of harming the cart or the system in case a pin looses contact?

When you remove the chassis of both, the cart and the console, there is more room for the cart to move inside the cartridge slot. And as you have to use a bit of pressure while soldering, the PCB will move. This way some pins may loose contact which is almost like pulling the cart, isn't it?

Maybe cleaning the cart can help to prevent this.

And even if not, the game may crash due to this (happened to me sometimes I accidentally hit Genesis or SNES carts while inserted). So it's not a 100% safeguard. That would be dumping the save. But as a GameDoctor cannot handle SEGA related stuff (that would be awesome ^^) that's not possible.

To make a long story short: I'll try it this way if it's not harming cart or console.

There may be the danger of loosing my safe anyway, but I have to try it at least. If it's still gone, that's just the way it is. I'm the one to blame for this situation as I didn't really realize the battery problem when I got the carts about a year ago.

Thanks everyone for helping out. I'll report the result of this operation once I've got time and those batteries didn't die in the meantime (the possibility is very high with carts that old).

This is a situation where I whip out the handle butane powered soldering iron. :)

Author	Message
F4yt Joined: 25 Jan 2008 Posts: 9 Location: Germany	Retaining SRAM while changing battery Posted: Mon Apr 16, 2012 7:40 am
F4yt Joined: 25 Jan 2008 Posts: 9 Location: Germany	Hi folks, as the title suggests, would it be possible to support the SRAM (that holds the saves) while exchanging the battery? I thought about a second battery or something connected in parallel (thus not rising the voltage). I have some carts still "living" on their first battery (namely Phantasy Star and Ys) and I'd like to keep some saves I've got. I also wonder if the SRAM is powered by the system while the cartridge is in use? Or is it powered by the battery only (even when the cart is used)? Thanks in advance for any information.

TmEE Joined: 31 Oct 2007 Posts: 458 Location: Estonia, Rapla city	Posted: Mon Apr 16, 2012 8:17 am
	Solder in another battery in parallel and then remove the old battery. They really don't like being in parallel. I've done it few times and it has worked, though best option is to dump the saves, change battery and write saves back but this needs some more special hardware.

Maxim Site Admin Joined: 19 Oct 1999 Posts: 8982 Location: London	Posted: Mon Apr 16, 2012 8:34 am
	I thought there was some hardware to power the SRAM from the console while connected, which would also deal with safely switching between the two - and hooking it up to a stable 5V+GND seems safer than the parallel battery thing.

F4yt Joined: 25 Jan 2008 Posts: 9 Location: Germany	Posted: Mon Apr 16, 2012 8:59 am
F4yt Joined: 25 Jan 2008 Posts: 9 Location: Germany	@TmEE So hooking up a battery during exchange would be possible. Then I'd hook it up directly to the chip (or somwhere else possible) to avoid accidentally desoldering both batteries during exchange. After that I'd provide the new battery and desolder the "bridge-battery". As I don't have any device for dumping saves (and for just two games with batteries right now) this is not really an option. @Maxim I'll check the board for 5V traces to the RAM once I get one of those gamebits. Anyone got any further experience regarding this method? Thanks so far for the info.

TmEE Joined: 31 Oct 2007 Posts: 458 Location: Estonia, Rapla city	Posted: Mon Apr 16, 2012 9:06 am
	When cart is plugged in the SRAM will get 5V and you can do the exchange then aswell, but I would advise disconnect the iron from wall when doing the soldering as I have had shorts because of grounding and lost SRAM contents due to it.

F4yt Joined: 25 Jan 2008 Posts: 9 Location: Germany	Posted: Mon Apr 16, 2012 9:13 am
F4yt Joined: 25 Jan 2008 Posts: 9 Location: Germany	@TmEE Very useful info, thanks! So heat up (maybe to a slightly higher temperature), unplug, solder, repeat... Then I'll buy a 50-Pin connector and wire up the 5V/GND pins. Should be a lot safer than anything else.

TmEE Joined: 31 Oct 2007 Posts: 458 Location: Estonia, Rapla city	Posted: Mon Apr 16, 2012 9:36 am
	Rather stick the cart into a working machine, or grab 5V from elsewhere and wire to some power supply bypass cap on the board. 50pin connector is a bit overkill

F4yt Joined: 25 Jan 2008 Posts: 9 Location: Germany	Posted: Mon Apr 16, 2012 11:37 am
F4yt Joined: 25 Jan 2008 Posts: 9 Location: Germany	Yeah, I thought kinda the same way right after posting. But I like to handle my carts with care, they're precious (^-^) In fact, one thing I thought of (before posting here) was: "Just stick it into the machine and do it." Maybe I even load the game just in case something goes wrong with the SRAM. But I somehow don't like the idea of soldering like that. So I'm going to look for a nice spot to hook up either a second battery or 5v. Thanks for all the information, it really helped a lot!

TmEE Joined: 31 Oct 2007 Posts: 458 Location: Estonia, Rapla city	Posted: Mon Apr 16, 2012 12:24 pm
	With doing it inside the machine you got one potential failsafe : The you can save ingame, which can fix any potential corruption that can occur.

F4yt Joined: 25 Jan 2008 Posts: 9 Location: Germany	Posted: Mon Apr 16, 2012 11:52 pm
F4yt Joined: 25 Jan 2008 Posts: 9 Location: Germany	Yeah, you see, I also thought about loading the saved game so I can save it back later. And there's no chance of harming the cart or the system in case a pin looses contact? When you remove the chassis of both, the cart and the console, there is more room for the cart to move inside the cartridge slot. And as you have to use a bit of pressure while soldering, the PCB will move. This way some pins may loose contact which is almost like pulling the cart, isn't it? Maybe cleaning the cart can help to prevent this. And even if not, the game may crash due to this (happened to me sometimes I accidentally hit Genesis or SNES carts while inserted). So it's not a 100% safeguard. That would be dumping the save. But as a GameDoctor cannot handle SEGA related stuff (that would be awesome ^^) that's not possible. To make a long story short: I'll try it this way if it's not harming cart or console. There may be the danger of loosing my safe anyway, but I have to try it at least. If it's still gone, that's just the way it is. I'm the one to blame for this situation as I didn't really realize the battery problem when I got the carts about a year ago. Thanks everyone for helping out. I'll report the result of this operation once I've got time and those batteries didn't die in the meantime (the possibility is very high with carts that old).

Chilly Willy Joined: 23 Jan 2011 Posts: 64 Location: The Land of Enchantment	Posted: Mon Apr 23, 2012 4:58 am
	This is a situation where I whip out the handle butane powered soldering iron. :)

Forums

View topic - Retaining SRAM while changing battery