Solder Sucker Meets Industrial Vacuum Pump


[borgartank] is starting a hackerspace with a few guys, and being the resident electronics guru, the task of setting up a half-decent electronics lab fell on his shoulders. They already have a few soldering stations, but [borgar] is addicted to the awesome vacuum desolderers he has at his job. Luckily, [bogar]‘s employer is keen to donate one of these vacuum desolderers, a very old model that has been sitting in a junk pile since before he arrived. The pump was shot, but no matter; it’s nothing a few modifications can’t fix.

The vacuum pump in the old desoldering station was completely broken, and word around the workplace is the old unit didn’t work quite well when it was new. After finding a 350 Watt vacuum pump – again, in the company junk pile – [bogar] hooked it up to the old soldering station. Everything worked like a charm.

After bolting the new and outrageously large pump to the back of the desoldering station, [bogar] wired up a relay to turn on the pump with the station’s 24V line. Everything worked as planned, netting the new hackerspace a 18 kg soldering station.

Tricky Repair of Power Driver for CNC Machine


Designing and building something from scratch is one thing. But repairing fried electronics is a much different type of dark art. This video from [Mike's Electric Stuff] is from more than a year ago, but we didn’t think you’d mind since what he accomplishes in it is so impressive. He’s got a burnt out pick and place hybrid power module which isn’t going to fix itself.

The power module construction includes a part that has chip-on-board-style MOSFETs and the circuitry that goes with them enclosed in a black plastic housing. It’s kind of like a submodule was encapsulated using the same plastic as integrated circuits. After cracking it open it appears the bonding wire has burnt away. [Mike] connects a jumper wire to one of the board traces in order to use an external MOSFET. This is much easier said than done since the module substrate is ceramic designed to dissipate heat. We’re amused by his technique of melting the jumper into the plastic housing to protect it from the heat sink that goes over the package. In the end he gets his CNC running again. This may not be the best long-term fix but he just needed to continue running until a proper replacement part arrives.

Oh, one more thing: the Metcal vacuum desolderer he uses in the video… do want!

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Diagnose and Repair a Yaesu FT-7800 Ham Radio

Yaesu FT-7800 Ham Radio

[Alan Wolke] aka [w2aew] was challenged to repair a friends Yaesu FT-7800 ham radio. This radio operates on two ham bands, 2 m VHF and 70 cm UHF. The complaint was that the 2 m side was not working but the 70 cm was transmitting fine. Alan started by verifying the complaint using a Bird watt meter with a 50 watt slug and terminating the signal into a 50 W dummy load. [Allen’s] bird meter is the type that has an RF sampler that can be connected to an oscilloscope for added signal viewing and validation.

After verifying that the radio was not working as described, Alan starts by glancing over the circuit board to look for any obvious damage. He then walks us through a block diagram as well as a circuit diagram of the FT-7800 radio before stepping us through the troubleshooting and diagnostics of radio repair. Even when he realizes he might have found the problem he still steps us through the remainder of his diagnostics. The skills and knowledge that Alan shares is extremely valuable to anybody looking to repair radios.

Spoiler alert. At the end of the first video he determines that the pin diodes near the final VHF output were bad. In the second video he reveals that he could no longer source these bad components. Through some clever evaluation of a more current Yaesu radio, [Allen] was able to find suitable replacement components. Lesson two ends with some surface mount solder rework tips as well as testing that the repair was successful.

And just in case you don’t know what a pin diode is, or is used for, Alan shares a third video covering just what this component is and does in a radio. You can follow the jump to watch all three videos.

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Repairing a mill that cost as much as a car


Years ago, someone at the bio-instrumentation lab at MIT needed to change a CMOS battery in the controller for a three axis mill. This reset the machine’s BIOS and was widely regarded as a bad move. The mill sat in the lab for a few years before  Prof. [Ian Hunter] donated it to MITERS – the student shop at MIT. And so the task of repairing a machine that cost as much as a car fell upon a plucky group of students.

The machine – a  Dyna-Myte 1007 has a 10″x7″x10″ work area, pneumatic tool changers and carousel, and the working for a fourth axis. It is. however, driven by an ancient Pentium computer running DOS with all the fun of ISA slots and IRQs that entails.

The MITERS began their repair by digging around in the software configuration, finding the axis drive is controlled via IRQ 3, which was currently occupied by COM 2. Changing that in the BIOS let the computer control the axes and, with a few solenoids and an air compressor, the tool carousel also worked.

With a bit of digging around, the MITERS also got the spindle working, giving them a very awesome and very expensive CNC milling machine for free. Even though the computer could be replaced with a $35 Raspberry Pi, we really have to admire the MITERS for fixing what they already had; it’s a cheaper and much, much faster way to get their new toy up and running.

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Vaporizer rebuild


Wait! Don’t click away yet. Yes, this is a vaporizer project, but it has the distinction of being the most electronics engineering oriented post on the subject we’ve ever featured. [Mm Nn's] vaporizer broke so he decided to fix it. After poking around inside it became clear that pretty much everything was trashed. So this ended up being a complete rebuild of all the support circuitry, with the heating element being the only electrical component he could salvage.

He started looking around for a power supply capable of driving the element from the Arizer V-tower vaporizer. He hoped that he could use a computer PSU but ended up having to buy one to suit; a Mean Well rs-100-24. He drives the system with a microcontroller (programmed in assembly) using PWM to adjust the element. Speaking of, there is a sensor built into the heating element that [Mm] isn’t using because he couldn’t figure out how to read from it. If you’ve got some ideas let us know in the comments.


The trials of repairing a MacBook


As a favor to a friend, [Phil] traded a unibody MacBook logic board for one with a broken headphone jack, a busted keyboard controller, and a nonfunctional fan. Not one to let bad hardware go to waste, he set off to repair this now-broken laptop by scavenging parts wherever he could. The whole thing ended up working, and became a very impressive display of soldering skill in the process.

The first step for the keyboard transplant was to cut a properly sized hole in the newer unibody MacBook for an older, pre-unibody MacBook Pro 17″ keyboard. This was done by cutting out the keyboard pan of the pre-unibody case and very carefully epoxying it into the unibody chassis. The MBP had a separate keyboard and trackpad controller, so of course [Paul] needed to find some space inside the chassis for these new electronics. This space was found next to the internal hard drive, and a liberal application of hot glue held everything together.

In the future, [Phil] plans on adding more LEDs, a 3.5 mm jack, and a USB to TTL converter – a necessity for any true ‘hacker’ laptop. It’s still a wonderful piece of work, and an incredible amount of effort and skill to get it where it is today.

Laptop backlight converted from CCFL to LED


[Lee Davison] acquired an Acer laptop that didn’t have a display anymore. He had enough parts on hand to add in an LCD panel and give it a CCFL backlight. But when he started looking for an inverter to drive the backlight he couldn’t find one. What he did have on hand were some smashed screens that had LED backlights and so the CCFL to LED backlight conversion project was born.

He tore into the LED display and found the driver board. Unfortunately he didn’t locate the datasheet for the exact LED driver, but he found one that was similar and was able to trace out the support circuitry on the PCB. This let him cut away the unneeded parts of the board without damaging the driver. He didn’t want to pull out the CCFL tubes until he was sure the LED conversion would work so he tried it out on another smashed panel (where does he come up with all these parts) and it worked great. Once he got everything in place he was very happy with the results. The only drawback to the system is that he doesn’t have the ability to dim the backlight.


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