Simple trick for replacing Game Boy cart batteries while retaining game saves

[Adr990] wants to make sure his Game Boy game saves aren’t lost to aging batteries. They’re stored in SRAM with a small coin cell inside the cartridge to keep the memory energized when the game is not being played. But if you pull out the battery in order to replace it the data will be lost in the process. It turns out that you can hot-swap the battery without too much effort. As shown in the video after the break, he disassembled the case of the cartridge, then replaced the battery while the Game Boy is switched on. The edge connector feeds power which will keep the SRAM active while the backup battery is removed. We’re sure this could be done with a bench supply as well, but you’ll need to do your own testing before risking those prized game saves.

The other option is to backup your SRAM before replacing the batteries. We’ve seen an AVR-based cartridge dumper, and also one that uses an Arduino. Both should be able to read and write SRAM data. [Read more…]

Separating a working scanner from its broken printer

The laser printer portion of this all-in-one machine gave up the ghost and [Entropia] couldn’t get it working again. But the scanner was still functioning so he decided to separate the scanner from its dead printer module.

The model in question is a Samsung SCX-4200. The design is actually perfect for separation because the scanner sits on top of the out feed tray of the printer. It can even be lifted to allow more room for printed pages to pile up. All he has to do is separate the hinged connector and reroute the flat cables. But the real question in [Entropia’s] mind was whether or not the control board would work without the laser printer components connected to it.

He carefully disassembled the unit, spilling toner here and there which is left over from a catastrophic knock-off toner cartridge incident. A quick test showed him that although the drivers complain that the paper tray is open, the scanner does still work. He glued the controller board seen on the left to the bottom of the scanner enclosure, and added some felt feet. Now his scanner is closer to the size you’d expect. And on the plus side he gained a geared stepper motor, laser scanning unit, exhaust fan, and a couple of solenoids to use in future projects.

Resurrecting a cellphone with blown USB circuitry

[Script] is pretty lucky. One of the engineers who designed his cellphone included over-voltage protection in the circuit. Of course you probably wouldn’t know about this if there wasn’t a service schematic available. But a bit of searching around let him resurrect the fried USB segment of his Nokia N900.

Now [Script] has been experimenting with portable solar power like the system featured at 25C3 a few years back. Unfortunately he made an error which routed 12V into the USB connector’s 5V rail. After this unfortunate mistake the phone would not longer connect via USB, or charge the battery. Luickly the N900 is a favorite with the hacker community (you can see all kinds of N900 related projects here at Hackaday) and [Script] found his way to their N900 Schematic page. Digging into page four he found part F5300 which is labeled 2.0A. He removed the PCB and shielding, and tested the part with a multimeter to confirm it was blown. A quick wire bridge got the phone charging again, but [Script] plans to position a new fuse as soon as he can source the part.

Who says these devices aren’t user serviceable? If we could just get our hands on more service schematics perhaps our gear would last longer.

Pop-up dragonfly robot could be the future of business cards

Engineers trying to be memorable at a job interview would be wise to pull one of these pop-up robots out of a wallet. This marvel of engineering uses a laminate construction technique to build a robot as a pop-up assembly. You can see the base used during the process, it’s a hexagon that serves as a scaffolding during the laminating process, and includes mechanical linkages that facilitate assembly.

The design calls for multiple layers of materials to be laser-cut to exacting specifications. Once all parts are completed, they are stacked using rods to align them, then fused together. One more trip through the laser cutter finishes the milling and the machine is ready for assembly. But with parts this small, you’ll want a solid method for putting everything together. The linkages we mentioned before allow for this when two parts of the scaffolding are separated. The only thing that makes this impossible as a business card is the need for a trip through the solder bath to cement the pieces in place. But perhaps some type of clasping mechanism could remove this need in the future.

Don’t miss the video after the break that explains the entire process. You’ll even get to see the little guy flap his wings. That’s all that it does for now, there isn’t any steering mechanism available as of yet.

[Read more…]

Dell Streak screen repair yields a few welcome surprises

dell-streak

[Rupert’s] friend cracked the screen on his beloved Dell Streak 5 phone and handed it off to see if [Rupert] could repair it. He says that the glass replacement was a relatively straightforward affair – a process he documented in thorough detail worthy of iFixit.

He did come across a few interesting tidbits along the way, including an Atmel Mega168P hanging out on the broken screen’s digitizer board, which now resides in his parts bin. The most intriguing thing [Rupert] discovered however was that the phone’s on-board memory chip wasn’t soldered in as he would have expected. Instead, he found a standard microSD slot with a 2GB card in tow. He didn’t happen to have a larger card on hand, but after researching a bit he did find out that swapping the card is a relatively simple process.

If you happen to have one of these phones sitting around, or come across a damaged unit at any point, it definitely seems worth it to resurrect it and change the factory card out for something along the lines of a 32GB model. We certainly wouldn’t complain if we had a rooted 32GB Streak kicking around!

Tutorial series shows you everything you need to salvage transformers from microwaves

mot-salvaging

Transformers certainly have a tendency to increase the cost of any project, especially if you need a large transformer to get the job done. Microwave ovens are great sources of free transformers, though they are not always in the shape required for your next build.

[Matt] put together three great tutorial videos covering the basics of salvaging Microwave Oven Transformers (MOTs), that anyone new to the process should watch before giving it a go. The first video covers MOT removal and disassembly, which is a time consuming yet easy process providing you follow [Matt’s] pointers.

The second video delves into transformer theory, and discusses how to achieve optimal performance when rebuilding an MOT or hand wrapping coils to fit your project specs. The third video in the series follows [Matt] as he rebuilds one of the salvaged transformers, documenting his pitfalls and successes along the way.

If you haven’t given much thought to salvaging MOTs, we definitely recommend taking a bit of time to watch the video series in full – it’s definitely worth it.

You can see the first video in the series after the jump – the rest can be found via the YouTube link above.

[Read more…]