A nice solution might be to replace the SRAM with FRAM - maybe the FM18W08-SGTR would work? I would need to check pinouts and voltages, but in theory you could mod one to power from the connector edge instead of battery, and use an FRAM IC. And before I forget - I believe the SRAM used (and the replacement I fitted) are primarily 5v parts. The N64 uses 3.3v logic levels. So that's another factor that could be at play here.
FRAM would be a much better solution to this problem than replacing with another battery powered SRAM. Drop an FRAM in and forget about it for the rest of it's existence xD
Years before I got my EverDrive 64 I used to own a CD64 Plus (game copier) it could backup N64 games and store them and load them from CD-Rs to its internal 256mb memory, one of its best features which this video has reminded me of was it also had a memory packs manager were you could format memory packs backup and restore them, because of this I only ever needed one memory pack for my N64. My CD64 Plus eventually died as it was made from cheap components and hot glue but it was the nutz at the time.
I rembember South Park 64 having a good file manager. That I was able to format and recover some memory cards that I couldnt with other cart file managers. Havent messed with n64 in years though. Not saying it would fix this ofc.
I did use the Southpark file manager too! I tried a bunch, and also tried the Everdrive (format game pak option) and that wouldnt work either. Was definitely the SRAM!
That's interesting; I've noticed some games definitely have a "better" interface for the manager than others. I assumed that every game that utilizes the memory card had a manager built in but that isn't true (Off Road Challenge comes immediately to mind). Then there are some games that have the manager even though they don't use a memory card.
I just dropped fram into my official N64 pack and it won't format using Perfect Dark, I'll have to give this a go. All solder joints are good so I'm stumped. We shall see!
I wonder if there's enough current provided to the mempack connector's 3.3v line to use buck/boost based lithium charger controller chips ? There's certainly enough physical space to fit one of the small drone-sized lipo packs in there with an sram. In terms of smd soldering i've been having great success using the paste + hand soldering, i've found that the way the paste wicks to the pin takes care of any unwanted bridging but i'm still very much learning to do smd work :D
Would there ever be a chance of a N64 booster pack mod. reason I ask would be there any reason not to try doubling the amount of ram if the system could handle it. not that any game would need it just would be great for home brew having more N64 ram to run emulation off an ever drive.
Yes, the PCB in this video seems to support larger chips. In theory it could be possible to piggyback a 2nd 62256 chip on there and with some added logic to switch between the chips on the upper address bit it could be made to work I think.
Yes, it's an interesting point, and there might be other factors to consider. In the case of the Neo Geo, when there's no battery at all - the system works! I ran mine like that for 3+ years and the SRAM was fine. Where I think the problem can occur in the MVS is when the battery has failed and it perhaps provides some resistance, so the power that normally feeds its VCC rail (via the charge circuit), perhaps pulls the VCC down below the logic level the data and address buses are driven with. At least that's what I think is happening on the MVS. But in this case there is no 'charge circuit' on these cheap mem packs, so I think there's much more chance of latchup even when the battery level drops over a few years. eg. imagine battery drops to 2.0v, and data / address bus logic level is 3.3v...
Excellent video, those weird studs on the chip are usually for some kind of battery pack that some manufactures make for their RAMs to make them into NVRAMs, ST Micro do ones called SNAPHAT.
I've had the battery die on an official pak and attempted to use it multiple times with the dead battery. I opened it up, replaced the battery and its been working fine. I believe it would save the game fine but it would be gone instantly after you powered off. Maybe they are powered from the console as well. Some of the third party packs are really shite inside;(bodge wires and cold joints galore) these don't look as bad. The prospect of putting a chip that didn't require battery power is very intriguing
I’ve never had a problem swapping batteries on my 3rd party paks. If it says “corrupted” then you usually just let the game software “reformat” the card or whatever. Are you saying that using them with a dead battery kills the SRAM?
Yes, depending on how they are wired. If the SRAM gets powered by the N64 via the cart edge, then it would likely be OK. But if the SRAM is solely powered by the battery, and the battery is flat or missing, then latch-up is entirely possible. I haven't got an original pack to see how they are wired, but on these the battery seems to provide the sole power to them.
so going by what you're saying, you will basically kill the SRAM simply by removing the battery, weather the battery is still good or not? What's the point in the pak giving you the ability to remove the battery then?
No, you can kill the SRAM by powering the unit without a battery - or a bad battery. The big problem with mine is the battery bay shorts out the contacts, so if you powered it with no battery, that would kill the SRAM. And the contacts are really bad, so when you do swap out the battery you need to make sure it is connecting before powering up.
AndehX Like a game cartridge with a removable battery, it’s internal and isn’t intended for end-user replacement. It’s intended to last a decade or two before running flat and losing your data. Still should’ve been engineered in a way so that the SRAM wouldn’t get fried when the battery dies. I’m surprised these 3rd party controller paks didn’t use soldered-in tabbed batteries like most SRAM game paks but that’s probably just parts bin engineering for you.
AndehX ...oh yeah: it also appears safe to preemptively remove/change the battery (Edit: With the checks/precautions Gadget just suggested ;)). It only kills it if you attempt to use the controller pak while the battery is dead or removed. Because most people wouldn’t consider changing the battery until after finding their saves gone, most people will have already fried it. Sucks!
Yes, you probably can! I completely forgot to focus on that aspect. But yes, pretty sure that's what the other 4 pins are for. Assuming you can go to a 1MBit chip from the current 256Kbit I have fitted.
I doubt that the battery or your drop killed the SRAM. All removing the battery would do would be to wipe the FAT and the root directory entries from the card (they use the FAT12 filesystem). And the SRAM would have reset to all 0xFF bytes when you removed the battery, giving the appearance of being both empty and having no free space left (free space is denoted as 0x000 in the FAT12 FAT. If you'd reformatted the original SRAM chip, the FAT and empty root directory structures would have been recreated, and it would have worked just as well.
No, it was a faulty SRAM! Formatting it using various methods there (including the format build into the Everdrive) always resulted in it no being usable. The battery not being connected properly caused a latch-up, killing the SRAM.
Thanks! Nor me! I couldn't believe that it had died just from the battery not making a proper connection tbh. I spend a number of days trying to rule everything out - but it 100% certainly had a dead SRAM at the end of the day. Worked fine before I removed the battery to measure it =/
That is strange.. the SRAM should have just emptied its self when the power was cut and you should have been able to just reformat it in the N64 just like you did with the new SRAM chip, maybe its just a defective RAM chip they used.
What has happened is the battery wasn't connected properly whilst it was powered, causing a latch-up fault. That does look to have been the cause. Before the battery was 1st removed to measure it, it was working perfectly. When the battery was re-installed, one of the connections made a really bad join to the point it wasn't powering the chip.
Wait - what shorted out the sram chip - removing the battery or powering it up without the battery? I can't imagine those would short through? On a side note I think soldering with a heatgun without a stencil for the chip itself is probably more trouble than its worth.
The battery wasn't providing a supply to the chip at one point (just because of how bad the battery connector is in design). That caused the latch-up =/
@@GadgetUK164 Just for clarification, that would mean that the same would happen if the battery died or wa removed, which you stated in the video. Odd to me that losing power at any time would destroy an SRAM.
@@GadgetUK164 Saw further details in your other comments: (Using one with a dead battery could kill the SRAM) depending on how they are wired. If the SRAM gets powered by the N64 via the cart edge, then it would likely be OK. But if the SRAM is solely powered by the battery, and the battery is flat or missing, then latch-up is entirely possible. I haven't got an original pack to see how they are wired, but on these the battery seems to provide the sole power to them. (You) can kill the SRAM by powering the unit without a battery - or a bad battery. The big problem with mine is the battery bay shorts out the contacts, so if you powered it with no battery, that would kill the SRAM. And the contacts are really bad, so when you do swap out the battery you need to make sure it is connecting before powering up.
I have 2 dead Nintendo 64, after cleaning them I couldn't start them. The contacts are clean, the power led comes on but black screen. I think the ram is bad on the board. Can I switch the on-board RDRAM with chips from, let's say a chip from a stick of rambus ram?
Off the top of my head - not 100% sure! You need to look at the part number of the RAM on the N64 (and its specs / pinout) and compare to the RDRAM on the DIMM / SIMM. It might be bespoke to the N64 - not sure!
I've not heard of that problem =/ You might need to take the controller to pieces in order to work out how to remove it, and inspect closely to work out how to stop it getting stuck in there!
I thought this video was going to be about the 4meg RAM expansion. Is it possible to make one of those? Maybe some FPGA magic would do it. Apparently, you can have 16meg RAM in a N64 and so that must mean using a 12meg expansion. I think, for the sake of homebrew, it should be done. As an aside, surely these 256k memory packs can be made too (since after all they are cloned too). Actually, might as well go for a full DD system but using say a FPGA "pretending" to be a DD disk (but it is actually just a stick or RAM or something).
It's of course possible to make anything =D But just not worth the effort tbh! It's far easier to just buy a spare one off eBay for £20 or something. They do use a specific type of RAM - RAMBUS I think? But I am sure you could replicate it with some other type of RAM. And yes, you could easily hombrew one of these memory packs for sure! Nice thin small PCB - easy to make your own, and maybe 3D print a shell. Use FRAM instead of SRAM and you don't need a battery =D
For the homebrew, it does seem kind of silly the way the n64 does not have a homebrew 16meg RAM upgrade (so that is basically 12meg + 4meg existing). And also for it to have something like the DD made (but maybe using a SDcard or emulated zipdisk in a 256Meg chunk of RAM pretending to be a HDD or whatever). Surely it will become a thing. I have hope for it.
You stated you couldn't remember whether you had gone and powered the memory pak back on with the coin cell contacts shorted (or not). Are we certain having done that may not have damaged the SRAM? I'm not clear whether what happens in this video actually supports the conclusions you reach at the end of it -- it would be nice to know for sure. Did you happen to save the "CPAK to File" using the EverDrive when it was supposedly corrupted, so that we can compare the corrupt 32k memory's contents against a normal 32k memory pak's contents using a hex editor? Interesting video as usual!
Pretty sure I didn't to be honest! The only reason I mentioned it is because that would almost certainly cause the failure. I believe the battery wasn't making a good connection. It's definitely a common problem related to the battery level dropping as I've read a lot about it and how swapping the battery is hit and miss. Changing the battery is often too late after it's dropped too low.
I would expect the SRAM to be empty after the failure addressing it was happening, since the contents were lost by the battery being removed (assuming you didn't power it on with the connectors shorted and fry it). If we had that empty 32k file, and could do a hex compare against the original dump before removing the battery, we could maybe see if the signature or nintendo data was there (alongside whatever saves were there, but I am thinking it might stand out somehow).
GadgetUK164 - Retro Gaming Repairs & Mods yeah a few "backup" really struggle and a couple or original wont work unless the disc is perfectly clean. The mega cd 2 read everything fine. Ill clean the laser lens first but i do have a replacement laser. The mega cd 2 was just the fuse. Someone gave it to me so free mega cd for me.
It's a good idea, but there's a problem with the mem packs I have - if you remove the battery, the + and - connectors for the battery SHORT! If the pack was powered by the N64 that would cause the N64 PSU fuse to pop probably. If the battery contacts don't short, and assuming the SRAM is powered by the N64 (not sure it is in mine), then you would be OK. But pretty sure with mine the battery is the only source of power to the SRAM, even when connected to the N64.
tbbw and if it were an original memory card you wouldn't be able to get in there with a soldering iron to replace it while it was plugged in :( unless you too the controller out of its shell too
It was more an idea of how not to loose your saves or damage the sram if it was undervoltage that was the cause. Just random idea that popped into my brain while watching the video that i wrote a comment about :)
You could solder some wires onto the battery connections on the PCB, connect up to another battery in parallel, then remove the onboard battery. Need to be careful whilst soldering though and you could use that technique to swap the chip - only the battery. If you try soldering the chip whilst its powered you would likely lose the data and possible kill the SRAM.
Interestingly enough, I have a ‘Joy Tech’ 64 memory card that comes with a warning sticker that reads “Recommend to change a new battery every 12 months. When changing battery, finished within 1 minute, otherwise the memory card will be unrecoverable to work.”
Sounds like the Joy Tech ones do at least have a capacitor in there to provide some charge whilst you swap out the battery - that assumes the battery hasn't dropped to 0v. I would certainly replace any CR-2032 cells in these every few years at least.
SRAM can have a good bit of data retention without any power on its own - just on the internal capacity of an IC. Not sure if it will hold a minute or so. Bad things happen when you short the power inputs though. Wait, is there possibly a diode to prevent that?
The diode seem to just be in series with the battery supply - presumed to protect against the battery going in the wrong way. that kind of exacerbates the problem since there's also a 0.7v drop from that too.
Mhm that's a 5V SRAM that you installed - recommended supply voltage 4.5V or higher, retention 2.0V. IO voltage needs to not be higher than supply voltage plus 0.5V. That's kind of hard to reach on a 3.3V system while running off a 2-2.5V (considering diode drop) battery supply. Sure the second diode isn't there to actually power the SRAM from the system voltage (with a bit of a drop) when running in console? Then the battery diode protects the battery against potentially explosive charging. Ultimately that's all they care about, as a cheap product it must only last as long as the warranty, which means likely before the first battery replacement is due.
@@GadgetUK164 I inserted it the first time, didn't boot. The 2nd time I pressed on it a bit from the top, and it booted but froze during the intro of Pokemon Stadium 4. And now it's just dead. Won't work with any kind of pressure. The cartridge pins do not run all the way down to the lengt of the cart where it meets the slot. Is that normal? I'm thinking of baking it in an over for a bit, or maybe using an eraser on the pins and then a fibreglass pen to rub the connectors with.
A nice solution might be to replace the SRAM with FRAM - maybe the FM18W08-SGTR would work? I would need to check pinouts and voltages, but in theory you could mod one to power from the connector edge instead of battery, and use an FRAM IC.
And before I forget - I believe the SRAM used (and the replacement I fitted) are primarily 5v parts. The N64 uses 3.3v logic levels. So that's another factor that could be at play here.
FRAM would be a much better solution to this problem than replacing with another battery powered SRAM. Drop an FRAM in and forget about it for the rest of it's existence xD
Years before I got my EverDrive 64 I used to own a CD64 Plus (game copier) it could backup N64 games and store them and load them from CD-Rs to its internal 256mb memory, one of its best features which this video has reminded me of was it also had a memory packs manager were you could format memory packs backup and restore them, because of this I only ever needed one memory pack for my N64. My CD64 Plus eventually died as it was made from cheap components and hot glue but it was the nutz at the time.
this sounds very similar to Doctor V64 (device that Nintendo hated so much because it was used for copying N64 games)
You posted this on my 23rd birthday...great video and I love the N64.
I rembember South Park 64 having a good file manager. That I was able to format and recover some memory cards that I couldnt with other cart file managers. Havent messed with n64 in years though. Not saying it would fix this ofc.
I did use the Southpark file manager too! I tried a bunch, and also tried the Everdrive (format game pak option) and that wouldnt work either. Was definitely the SRAM!
That's interesting; I've noticed some games definitely have a "better" interface for the manager than others. I assumed that every game that utilizes the memory card had a manager built in but that isn't true (Off Road Challenge comes immediately to mind). Then there are some games that have the manager even though they don't use a memory card.
Isnt it volatile? No power=immediate erase of all data?
I just dropped fram into my official N64 pack and it won't format using Perfect Dark, I'll have to give this a go. All solder joints are good so I'm stumped. We shall see!
I fixed a bunch with Beetle Adventure Racing, South Park is a good one too.
I wonder if there's enough current provided to the mempack connector's 3.3v line to use buck/boost based lithium charger controller chips ?
There's certainly enough physical space to fit one of the small drone-sized lipo packs in there with an sram.
In terms of smd soldering i've been having great success using the paste + hand soldering, i've found that the way the paste wicks to the pin takes care of any unwanted bridging but i'm still very much learning to do smd work :D
Thank you GadgetUK164, for this memory card SRAM replacement repair, its much appreciated.
Would there ever be a chance of a N64 booster pack mod. reason I ask would be there any reason not to try doubling the amount of ram if the system could handle it. not that any game would need it just would be great for home brew having more N64 ram to run emulation off an ever drive.
Yes, the PCB in this video seems to support larger chips. In theory it could be possible to piggyback a 2nd 62256 chip on there and with some added logic to switch between the chips on the upper address bit it could be made to work I think.
@@GadgetUK164 Thank you sir!
Thankfully the VMU on the Sega Dreamcast doesn't have this issue with sram. Those really eat batteries so does the wii remotes.
Very interesting, didn't realise lack of battery could ever kill SRAM. Cheers for the vid!
Yes, it's an interesting point, and there might be other factors to consider. In the case of the Neo Geo, when there's no battery at all - the system works! I ran mine like that for 3+ years and the SRAM was fine. Where I think the problem can occur in the MVS is when the battery has failed and it perhaps provides some resistance, so the power that normally feeds its VCC rail (via the charge circuit), perhaps pulls the VCC down below the logic level the data and address buses are driven with. At least that's what I think is happening on the MVS. But in this case there is no 'charge circuit' on these cheap mem packs, so I think there's much more chance of latchup even when the battery level drops over a few years. eg. imagine battery drops to 2.0v, and data / address bus logic level is 3.3v...
Another interesting video about back-in-the-day hardware.Thanks.
I agree with you on the hot air as well. Very useful for removing a chip but I always just drag solder when reinstalling
Excellent video, those weird studs on the chip are usually for some kind of battery pack that some manufactures make for their RAMs to make them into NVRAMs, ST Micro do ones called SNAPHAT.
Thanks for the info there =D Very useful =D
I've had the battery die on an official pak and attempted to use it multiple times with the dead battery. I opened it up, replaced the battery and its been working fine. I believe it would save the game fine but it would be gone instantly after you powered off. Maybe they are powered from the console as well. Some of the third party packs are really shite inside;(bodge wires and cold joints galore) these don't look as bad. The prospect of putting a chip that didn't require battery power is very intriguing
When I get more time I will install an FRAM into one of these! =D
I’ve never had a problem swapping batteries on my 3rd party paks. If it says “corrupted” then you usually just let the game software “reformat” the card or whatever. Are you saying that using them with a dead battery kills the SRAM?
Yes, depending on how they are wired. If the SRAM gets powered by the N64 via the cart edge, then it would likely be OK. But if the SRAM is solely powered by the battery, and the battery is flat or missing, then latch-up is entirely possible. I haven't got an original pack to see how they are wired, but on these the battery seems to provide the sole power to them.
so going by what you're saying, you will basically kill the SRAM simply by removing the battery, weather the battery is still good or not? What's the point in the pak giving you the ability to remove the battery then?
No, you can kill the SRAM by powering the unit without a battery - or a bad battery. The big problem with mine is the battery bay shorts out the contacts, so if you powered it with no battery, that would kill the SRAM. And the contacts are really bad, so when you do swap out the battery you need to make sure it is connecting before powering up.
AndehX Like a game cartridge with a removable battery, it’s internal and isn’t intended for end-user replacement. It’s intended to last a decade or two before running flat and losing your data. Still should’ve been engineered in a way so that the SRAM wouldn’t get fried when the battery dies. I’m surprised these 3rd party controller paks didn’t use soldered-in tabbed batteries like most SRAM game paks but that’s probably just parts bin engineering for you.
AndehX ...oh yeah: it also appears safe to preemptively remove/change the battery (Edit: With the checks/precautions Gadget just suggested ;)). It only kills it if you attempt to use the controller pak while the battery is dead or removed. Because most people wouldn’t consider changing the battery until after finding their saves gone, most people will have already fried it. Sucks!
can you install bigger ram chip ?
there are those 4 unused pads and resistor place,
is that the only phisical difference between 128/256/512k boards?
Yes, you probably can! I completely forgot to focus on that aspect. But yes, pretty sure that's what the other 4 pins are for. Assuming you can go to a 1MBit chip from the current 256Kbit I have fitted.
So, topic for next video, right? 😀
Excellent video Gadget Man :D
Hi I believe Tetris for the N64 has a repair pak option and it worked for my memory card. Either Tetris or Wetrix.
Thanks, the repair option wouldn't have worked here as the SRAM had died =/
I doubt that the battery or your drop killed the SRAM. All removing the battery would do would be to wipe the FAT and the root directory entries from the card (they use the FAT12 filesystem). And the SRAM would have reset to all 0xFF bytes when you removed the battery, giving the appearance of being both empty and having no free space left (free space is denoted as 0x000 in the FAT12 FAT. If you'd reformatted the original SRAM chip, the FAT and empty root directory structures would have been recreated, and it would have worked just as well.
No, it was a faulty SRAM! Formatting it using various methods there (including the format build into the Everdrive) always resulted in it no being usable. The battery not being connected properly caused a latch-up, killing the SRAM.
Great vid dident think it would be latch up
Thanks! Nor me! I couldn't believe that it had died just from the battery not making a proper connection tbh. I spend a number of days trying to rule everything out - but it 100% certainly had a dead SRAM at the end of the day. Worked fine before I removed the battery to measure it =/
That is strange.. the SRAM should have just emptied its self when the power was cut and you should have been able to just reformat it in the N64 just like you did with the new SRAM chip, maybe its just a defective RAM chip they used.
What has happened is the battery wasn't connected properly whilst it was powered, causing a latch-up fault. That does look to have been the cause. Before the battery was 1st removed to measure it, it was working perfectly. When the battery was re-installed, one of the connections made a really bad join to the point it wasn't powering the chip.
i noticed that the pcb has a few extra pads could you put a larger sram chip in it?
Yes, someone asked that too =D I think a 1Mbit chip would probably work.
Nice video as always
My memory pack doesn't have a battery or any backup whatsoever.
Wait - what shorted out the sram chip - removing the battery or powering it up without the battery? I can't imagine those would short through?
On a side note I think soldering with a heatgun without a stencil for the chip itself is probably more trouble than its worth.
The battery wasn't providing a supply to the chip at one point (just because of how bad the battery connector is in design). That caused the latch-up =/
Oh wow that is horrible.
@@GadgetUK164 Just for clarification, that would mean that the same would happen if the battery died or wa removed, which you stated in the video. Odd to me that losing power at any time would destroy an SRAM.
@@GadgetUK164 Saw further details in your other comments: (Using one with a dead battery could kill the SRAM) depending on how they are wired. If the SRAM gets powered by the N64 via the cart edge, then it would likely be OK. But if the SRAM is solely powered by the battery, and the battery is flat or missing, then latch-up is entirely possible. I haven't got an original pack to see how they are wired, but on these the battery seems to provide the sole power to them.
(You) can kill the SRAM by powering the unit without a battery - or a bad battery. The big problem with mine is the battery bay shorts out the contacts, so if you powered it with no battery, that would kill the SRAM. And the contacts are really bad, so when you do swap out the battery you need to make sure it is connecting before powering up.
if the battery dies you have to format it otherwise it will show that's its full
That wasn't the case with this - the SRAM had died.
I have 2 dead Nintendo 64, after cleaning them I couldn't start them. The contacts are clean, the power led comes on but black screen. I think the ram is bad on the board. Can I switch the on-board RDRAM with chips from, let's say a chip from a stick of rambus ram?
Off the top of my head - not 100% sure! You need to look at the part number of the RAM on the N64 (and its specs / pinout) and compare to the RDRAM on the DIMM / SIMM. It might be bespoke to the N64 - not sure!
cool video. Do you know a good way of removing the unofficial memory paks without damaging the controller? im really stuck
I've not heard of that problem =/ You might need to take the controller to pieces in order to work out how to remove it, and inspect closely to work out how to stop it getting stuck in there!
I thought this video was going to be about the 4meg RAM expansion. Is it possible to make one of those? Maybe some FPGA magic would do it. Apparently, you can have 16meg RAM in a N64 and so that must mean using a 12meg expansion. I think, for the sake of homebrew, it should be done. As an aside, surely these 256k memory packs can be made too (since after all they are cloned too). Actually, might as well go for a full DD system but using say a FPGA "pretending" to be a DD disk (but it is actually just a stick or RAM or something).
It's of course possible to make anything =D But just not worth the effort tbh! It's far easier to just buy a spare one off eBay for £20 or something. They do use a specific type of RAM - RAMBUS I think? But I am sure you could replicate it with some other type of RAM. And yes, you could easily hombrew one of these memory packs for sure! Nice thin small PCB - easy to make your own, and maybe 3D print a shell. Use FRAM instead of SRAM and you don't need a battery =D
For the homebrew, it does seem kind of silly the way the n64 does not have a homebrew 16meg RAM upgrade (so that is basically 12meg + 4meg existing). And also for it to have something like the DD made (but maybe using a SDcard or emulated zipdisk in a 256Meg chunk of RAM pretending to be a HDD or whatever). Surely it will become a thing. I have hope for it.
You stated you couldn't remember whether you had gone and powered the memory pak back on with the coin cell contacts shorted (or not). Are we certain having done that may not have damaged the SRAM? I'm not clear whether what happens in this video actually supports the conclusions you reach at the end of it -- it would be nice to know for sure.
Did you happen to save the "CPAK to File" using the EverDrive when it was supposedly corrupted, so that we can compare the corrupt 32k memory's contents against a normal 32k memory pak's contents using a hex editor? Interesting video as usual!
Pretty sure I didn't to be honest! The only reason I mentioned it is because that would almost certainly cause the failure. I believe the battery wasn't making a good connection. It's definitely a common problem related to the battery level dropping as I've read a lot about it and how swapping the battery is hit and miss. Changing the battery is often too late after it's dropped too low.
And after the failure, the dump of the CPAK was just blank - no data there at all. So SRAM just wasn't holding anything.
I would expect the SRAM to be empty after the failure addressing it was happening, since the contents were lost by the battery being removed (assuming you didn't power it on with the connectors shorted and fry it). If we had that empty 32k file, and could do a hex compare against the original dump before removing the battery, we could maybe see if the signature or nintendo data was there (alongside whatever saves were there, but I am thinking it might stand out somehow).
Actually, scratch that, if it was all zeroes, then you wouldn't even need to compare -- the original copy would be enough to examine. :^)
You filming in a layby?
Interesting video. I fixed a Sega Cd 2, congrats to me, but discovered my multi mega cd isnt performing well. 😭
LOL! Well done! Nothing beats that "I fixed it fuzzy feeling" =D How is it not performing well - struggling to read?
GadgetUK164 - Retro Gaming Repairs & Mods yeah a few "backup" really struggle and a couple or original wont work unless the disc is perfectly clean. The mega cd 2 read everything fine. Ill clean the laser lens first but i do have a replacement laser.
The mega cd 2 was just the fuse. Someone gave it to me so free mega cd for me.
Hola... Necesito reparar la conexión del slot... Donde se conecta el Jumper pack... Gracias.
I wonder what would happen if you plug the memory cart into the controller and then swap the battery while it's getting power from the controller.
It's a good idea, but there's a problem with the mem packs I have - if you remove the battery, the + and - connectors for the battery SHORT! If the pack was powered by the N64 that would cause the N64 PSU fuse to pop probably. If the battery contacts don't short, and assuming the SRAM is powered by the N64 (not sure it is in mine), then you would be OK. But pretty sure with mine the battery is the only source of power to the SRAM, even when connected to the N64.
Well seems my curiosity is cured with that "what if" :)
tbbw and if it were an original memory card you wouldn't be able to get in there with a soldering iron to replace it while it was plugged in :( unless you too the controller out of its shell too
It was more an idea of how not to loose your saves or damage the sram if it was undervoltage that was the cause.
Just random idea that popped into my brain while watching the video that i wrote a comment about :)
You could solder some wires onto the battery connections on the PCB, connect up to another battery in parallel, then remove the onboard battery. Need to be careful whilst soldering though and you could use that technique to swap the chip - only the battery. If you try soldering the chip whilst its powered you would likely lose the data and possible kill the SRAM.
I was looking for a expansion pak repair video guess mine is unfixable
South Park rally was suuuuch an amazing game.
Interestingly enough, I have a ‘Joy Tech’ 64 memory card that comes with a warning sticker that reads “Recommend to change a new battery every 12 months. When changing battery, finished within 1 minute, otherwise the memory card will be unrecoverable to work.”
Sounds like the Joy Tech ones do at least have a capacitor in there to provide some charge whilst you swap out the battery - that assumes the battery hasn't dropped to 0v. I would certainly replace any CR-2032 cells in these every few years at least.
SRAM can have a good bit of data retention without any power on its own - just on the internal capacity of an IC. Not sure if it will hold a minute or so.
Bad things happen when you short the power inputs though. Wait, is there possibly a diode to prevent that?
The diode seem to just be in series with the battery supply - presumed to protect against the battery going in the wrong way. that kind of exacerbates the problem since there's also a 0.7v drop from that too.
Mhm that's a 5V SRAM that you installed - recommended supply voltage 4.5V or higher, retention 2.0V. IO voltage needs to not be higher than supply voltage plus 0.5V. That's kind of hard to reach on a 3.3V system while running off a 2-2.5V (considering diode drop) battery supply. Sure the second diode isn't there to actually power the SRAM from the system voltage (with a bit of a drop) when running in console? Then the battery diode protects the battery against potentially explosive charging. Ultimately that's all they care about, as a cheap product it must only last as long as the warranty, which means likely before the first battery replacement is due.
Hi! Would you be kind enough to help me with issues on a fault Expansion Pak from Japan?
What's the problem?
@@GadgetUK164 I inserted it the first time, didn't boot. The 2nd time I pressed on it a bit from the top, and it booted but froze during the intro of Pokemon Stadium 4. And now it's just dead. Won't work with any kind of pressure. The cartridge pins do not run all the way down to the lengt of the cart where it meets the slot. Is that normal? I'm thinking of baking it in an over for a bit, or maybe using an eraser on the pins and then a fibreglass pen to rub the connectors with.
i didnt know cr2032 dont leak.
Technically they probably can, but I've never seen one leak. They tend to just go low voltage and just sit there. Occasionally swell a bit.
GadgetUK164 - Retro Gaming Repairs & Mods i opened my Sega Multi Mega and it uses a rechargeable cr2032. Didnt know they existed.
Yeah, the Mega CD v1 has a rechargeable CR2032 I think too!
Huge suggestion, leave music out of your instructional videos. It's completely unnecessary.
Thanks, it was way too loud on my early videos! Music is used much less now and a lot quieter.
Is it possible to replace the eeprom or flash chips in original cartridges once they die?
Not easily I think - the N64 cards use special serial PROMs =/
@@GadgetUK164 thank you