Flashed the wrong firmware? Swap out the LCD to match!

We always joke about the hardware guys saying that they’ll fix it in firmware, and vice-versa, but this is ridiculous. When [Igor] tried to update his oscilloscope and flashed the wrong firmware version in by mistake, he didn’t fix it in firmware. Instead, he upgraded the LCD display to match the firmware.

See, Siglent doesn’t make [Igor]’s DSO any more; they stopped using the 4:3 aspect ratio screens and replaced them with wider versions. Of course, this is an improvement for anyone buying a new scope, but not if you’ve got the small screen in yours and can’t see anything anymore. After playing around with flashing other company’s firmware (for a similar scope) and failing to get it done over the JTAG, he gave up on the firmware and started looking for a hardware solution.

It turns out that a few SMT resistors set the output screen resolution. After desoldering the appropriate resistors, [Igor] bought a new 7″ LCD screen online only to find out that it has a high-voltage backlight and that he’d need to build an inverter (and hide the noisy circuit inside his oscilloscope). Not daunted, he went digging through his junk box until he found a backlight panel of the right size from another display.

Yet more small soldering, and he had frankensteined a new backlight into place. Of course, the larger LCD won’t fit the case without some cutting, double-sided tape, and a healthy dose of black tape all around insulates the loose electricals. Et voilá!

We have to hand it to [Igor], he’s got moxie. It’s an ugly hack, but it’s a definite screen upgrade, and a lesser hacker would have stopped after flashing the wrong firmware and thrown the thing in the trash. We’d be proud to have that scope sitting on our desk; it’s a definite conversation starter, and a badge of courage to boot.

Macintosh Hard Drive Repair

The Macintosh II was a popular computer in the era before Apple dominated the coffee shop user market, but for those of us still using our Mac II’s you may find that your SCSI hard drive isn’t performing the way that it should. Since this computer is somewhat of a relic and information on them is scarce, [TheKhakinator] posted his own hard drive repair procedure for these classic computers.

The root of the problem is that the Quantum SCSI hard drives that came with these computers use a rubber-style bump stop for the head, which becomes “gloopy” after some time. These computers are in the range of 28 years old, so “some time” is relative. The fix involves removing the magnets in the hard drive, which in [TheKhakinator]’s case was difficult because of an uncooperative screw, and removing the rubber bump stops. In this video, they were replaced with PVC, but [TheKhakinator] is open to suggestions if anyone knows of a better material choice.

This video is very informative and, if you’ve never seen the inside of a hard drive, is a pretty good instructional video about the internals. If you own one of these machines and are having the same problems, hopefully you can get your System 6 computer up and running now! Once you do, be sure to head over to the retro page and let us know how you did!

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No user Serviceable Parts Inside? The rise of the Fix-It Culture

[Source: 1950s Television]
My first job out of high school was in a TV shop. I was hired mainly for muscle; this was the early 1980s and we sold a lot of console TVs that always seemed to need to be delivered to the third floor of a walk up. But I also got to do repair work on TVs and stereos, and I loved it. Old TVs from the 60s and 70s would come in, with their pre-PCB construction and hand-wired chassis full of terminal strips and point to point wiring that must have been an absolute nightmare to manufacture. We’d replace dodgy caps, swap out tubes, clean the mechanical tuners, and sometimes put a new picture tube in  – always the diagnosis that customers dreaded the most, like being told they’d need a heart transplant. We kept those old sets alive, and our customers felt like they were protecting their investment in their magnificent Admiral or Magnavox console with the genuine – and very, very heavy – walnut cabinet.

I managed to learn a lot from my time as a TV repairman, and I got the bug for keeping things working well past the point which a reasonable person would recognize as the time to go shopping for a new one. Fixing stuff is where I really shine, and my house is full of epic (in my mind, at least) repairs that have saved the family tens of thousands of dollars over the years. Dishwasher making a funny noise? I’ll just pull it out to take a look. You say there’s a little shimmy in the front end when you brake? Pull the car into the garage and we’ll yank the wheels off. There’s basically nothing I won’t at least try to fix, and more often than not, I succeed.

I assumed that my fix-it bug made me part of a dying breed of cheapskates and skinflints, but it appears that I was wrong. The fix-it movement seems to be pretty healthy right now, fueled in part by the explosion in information that’s available to anyone with basic internet skills.

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Saving an Alarm System Remote and $100

[Simon] has been using his home alarm system for over six years now. The system originally came with a small RF remote control, but after years of use and abuse it was finally falling apart. After searching for replacement parts online, he found that his alarm system is the “old” model and remotes are no longer available for purchase. The new system had similar RF remotes, but supposedly they were not compatible. He decided to dig in and fix his remote himself.

He cracked open the remote’s case and found an 8-pin chip labeled HCS300. This chip handles all of the remote’s functions, including reading the buttons, flashing the LED, and providing encoded output to the 433MHz transmitter. The HCS300 also uses KeeLoq technology to protect the data transmission with a rolling code. [Simon] did some research online and found the thew new alarm system’s remotes also use the same KeeLoq technology. On a hunch, he went ahead and ordered two of the newer model remotes.

He tried pairing them up with his receiver but of course it couldn’t be that simple. After opening up the new remote he found that it also used the HCS300 chip. That was a good sign. The manufacturer states that each remote is programmed with a secret 64-bit manufacturer’s code. This acts as the encryption key, so [Simon] would have to somehow crack the key on his original chip and re-program the new chip with the old key. Or he could take the simpler path and swap chips.

A hot air gun made short work of the de-soldering and soon enough the chips were in place. Unfortunately, the chips have different pinouts, so [Simon] had to cut a few traces and fix them with jumper wire. With the case back together and the buttons in place, he gave it a test. It worked. Who needs to upgrade their entire alarm system when you can just hack the remote?

Find and Repair a 230kV 800Amp Oil-Filled Power Cable Feels Like Mission Impossible

How do you fix a shorted cable ? Not just any cable. An underground, 3-phase, 230kV, 800 amp per phase, 10 mile long one, carrying power from a power station to a distribution centre. It costs $13,000 per hour in downtime, counting 1989 money, and takes 8 months to fix. That’s almost $75 million. The Los Angeles Department of Water and Power did this fix about 26 years ago on the cable going from the Scattergood Steam Plant in El Segundo to a distribution center near Bundy and S.M. Blvd. [Jamie Zawinski] posted details on his blog in 2002. [Jamie] a.k.a [jwz] may be familiar to many as one of the founders of Netscape and Mozilla.

To begin with, you need Liquid Nitrogen. Lots of it. As in truckloads. The cable is 16 inch diameter co-axial, filled with 100,000 gallons of oil dielectric pressurised to 200 psi. You can’t drain out all the oil for lots of very good reasons – time and cost being on top of the list. That’s where the LN2 comes in. They dig holes on both sides (20-30 feet each way) of the fault, wrap the pipe with giant blankets filled with all kind of tubes and wires, feed LN2 through the tubes, and *freeze* the oil. With the frozen oil acting as a plug, the faulty section is cut open, drained, the bad stuff removed, replaced, welded back together, topped off, and the plugs are thawed. To make sure the frozen plugs don’t blow out, the oil pressure is reduced to 80 psi during the repair process. They can’t lower it any further, again due to several compelling reasons. The cable was laid in 1972 and was designed to have a MTBF of 60 years.

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Frankensteined Cordless Drill Lives Again

With tools, especially cordless tools, you’re going to pay now or pay later. On one hand, you can spend a bunch of money up front and get a quality tool that will last a long time. The other option is purchasing a cheap cordless tool that won’t last long, having to replace it later and thus spending more money. With cheap cordless tools it is common for the battery to fail before the physical tool making that tool completely unusable. Sure, another battery could be purchased but sometimes they cost just as much as the tool and battery combo originally did. So what’s a cordless tool user to do?

[EngergySaver] had a set of DeWalt cordless tools with a bunch of working batteries. He also had a cheap drill where the battery had died. His bundle of tools included two flashlights, one of which the case physically broke in half, probably from a clumsy drop. Instead of tossing the broken flashlight pieces in the garbage, [EngergySaver] kept them around for a while. Then one day he had the idea of combining the base of the broken DeWalt flashlight with the top of the old battery-less drill. He had the parts so why not?

The battery pack was 18 volt and the cheap drill expected 16.8 volts. [EngergySaver] figured the voltages were close enough and decided not to worry about the difference during his hack. He started by disassembling both the drill and flashlight down to the bare plastic housings. He marked an appropriate place to splice the handles and made some cuts. After the wiring was spliced together and the tool casings reassembled, a piece of sheet metal was cut and bent around the handle at the joint between flashlight and drill. Hose clamps hold the sheet metal tight around the handles, keeping the new hybrid tool together. And although we’re not crazy about the sheet metal and hose clamp method, it seems to be working just fine. With a little work and ingenuity [EngergySaver] resurrected an old tool for our favorite price; $0.

Dewalt Radio Repair

We’re suckers for repair videos and this Dewalt worksite radio repair (YouTube Link) from Hackaday alum [Todd Harrison] is no exception. Like a detective story, we’re always trying to guess who did it.

In his first video [Todd] traced the issue down to a faulty 6 volt regulator which was pushing out 8 volts. He fixed that by hacking a LM317 into the circuit to replace the original non-adjustable part. That helped but after a few days the radio failed again. So here he traced out the voltages to find the second culprit. Along the way, we get to see some of the nicer features of his Fluke 87 and 289 meters. As well as puzzling over the some of the design decisions in the radios construction, before identifying the final issue.

We won’t spoil the surprise, but find out how Todd solves this riddle, wrapped in a mystery, inside an enigma in the video below!

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