[Quinn] Resurrects An Amplifier That Experienced Death-by-capacitor

September 12, 2012 by Mike Szczys 28 Comments

[Quinn Dunki] is adding wireless audio to all of the rooms in her home. She’s going with Airplay, snatching up used or refurbished Airport Express units because of their ability to work with both her existing WiFi and the Airplay protocol. The last piece in the puzzle is to get an Amp and she chose the small unit seen above. The problem is that it was dead on arrival and she couldn’t get the company to respond to her issue. So she cracked it open and fixed it right up.

The offenders are the three electrolytic capacitors at the top of the picture. She took some close-up images of each and you can’t miss the fact that they’re blown out. These are often among the higher price-per-unit parts and manufactures try to pinch the penny as much as possible. Add to it the heat in a small enclosure like this one and you’ve got a failure. [Quinn] dug through her junk bin but the size of the replacement had to be a perfect match so she ended up putting in a parts order. The new caps fit and work perfectly as you can hear in the clip after the break.

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Dell Streak Screen Repair Yields A Few Welcome Surprises

March 4, 2012 by Mike Nathan 23 Comments

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[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

March 3, 2012 by Mike Nathan 23 Comments

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.

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Improving Your Flight Sim Experience With Hall Effect Sensors

February 14, 2012 by Mike Nathan 26 Comments

hall-effect-controls

[Gene Buckle] built himself a nice custom cockpit for playing Flight Simulator, but during use he found that the gimbal he constructed for the pitch and roll controls was nearly unusable. He narrowed the problem down to the potentiometers he used to read the angle of the controls, so he set off to find a suitable and more stable replacement.

He figured that Hall effect sensors would be perfect for the job, so he picked up a pair of Allegro 1302 sensors and began fabricating his new control inputs. He mounted a small section of a pen into a bearing to use as an input shaft, attaching a small neodymium magnet to either side. Since he wanted to use these as a drop-in replacement for the pots, he had to fabricate a set of control arms to fit on the pen segments before installing them into his cockpit.

Once everything was set, he fired up his computer and started the Windows joystick calibration tool. His potentiometer-based controls used to show a constant jitter of +/- 200-400 at center, but now the utility displays a steady “0”. We consider that a pretty good result!

[Thanks, Keith]

Tutorial: Replacing Bad Capacitors

January 17, 2012 by Brian Benchoff 50 Comments

[glytch] sent in a tutorial on replacing dying capacitors on a motherboard, and we honestly can’t think of a better subject for an introductory tutorial. There’s nothing like having your friends think you’re a wizard for bringing broken electronics back from the grave.

For the repair a dead motherboard was [glytch]’s quarry. After taking a look at the board, he found a few bulging caps that were ready to burst. After ordering a few caps with the same voltage, capacitance, and dimensions (trust us, you want the same size cap), [glytch] took an iron and desoldering braid to the board and replaced a few caps.

Sooner or later, all capacitors are going to go break down. This isn’t always a bad thing – we picked up quite a few “broken LCD monitors” in the years after the capacitor plague and repaired them with a few dollars worth of caps. A lot of the caps in our late 80s computers have been replaced, and these machines are still chugging along.

Adventures In Resurrecting A No-name IP Webcam

November 23, 2011 by Mike Nathan 7 Comments

webcam-repair

As many of us do, [Steaky] serves as a kind of on-call help desk for his family. His father in law recently contacted him because his pan and tilt webcam died, and he wanted to see if it could be fixed. Never turning down a challenge, [Steaky] decided to give it a shot.

He ended up having to disassemble it since the camera was completely unresponsive, and what he found inside piqued his interest. The no-name camera sported an ARM microprocessor at its core, and it seems that some of its pins were damaged due to a poorly designed case. He figured resoldering the pins would do the trick, but that wasn’t the end of his adventures.

As he dug deeper into the device, he found that the camera essentially killed itself, reading and writing data to the wrong places due to the damaged pins on the processor. After plenty of searching around, he was able to find a somewhat compatible firmware image, though not everything worked properly.

His father in law was so impressed with his work that he asked for the camera back, even though [Steaky] hadn’t fully repaired it yet. While he bid the camera goodbye, we’re pretty sure he’d be more than happy to reclaim it for a few days if any of our readers had some additional insight or resources that might help him finish the job.

Simple Earphone Repair Saves A Big Chunk Of Cash

November 1, 2011 by Mike Nathan 26 Comments

shure_earphone_repair

[Spode] has been rocking out with a pair of Shure E4C earphones for about six years now, and he has no intentions of buying another set any time soon. The earphones cost him £200, so when the right channel started acting up, he decided to fix them rather than toss them in the trash bin.

His first attempt was successful, but just barely so. He ended up damaging the earphone case pretty badly, and in time the same problem reappeared. Undeterred, he opted to fix them once again, but this time around he did things differently.

Upon disassembling them, he found that his repair job had become frayed over time. [Spode] desoldered both drivers from the wires and cut them back a bit to expose some nice clean (and structurally sound) cable. He spent a little more time carefully soldering things back together to mitigate the chances of having to repair them again before replacing both earphone shells with a bit of black Sugru.

Having saved himself £200, [Spode] is quite happy with the repair. We probably would have tied an underwriter’s knot in each cable before soldering them to the drivers in the name of strain relief, though the Sugru should help with that.