I think it is just great when a problem can be analysed like this, a solution propsed and then implemented at very little cost. You just have to keep telling yourself there is a solution to the problem and quite often it doesn't have to cost a lot of money. Of course, throwing money at a problem also produces good solutions.

Dubbie

I am still pretty new in terms of experience in Electronics Engineering. So my fix may be quite simple but it is something I am proud of and really "saved the day". At the beginning of this year, I interned at a software startup who recently tried going into embedded systems.

When I joined, they were prototyping with the new STM32WB-series microcontrollers. I guess due to lack of expertise, the hardware team rushed through the circuit design. The PCBA had already been fabricated and I was given a board to debug and try out.

I was told that there was an issue with the accelerometers on board. We were debugging the I2C communication for days.

After doing measurements, I eventually found out that the 1.8V power supply to the accelerometer was only giving 1.25V. I found out that the power supply was wrongly designed and no one was aware of it yet.

The designer mistakenly chose the MAX1920 (adjustable voltage) rather than the MAX1921 (fixed voltage version at 1.8V).

You see, the MAX1920 and MAX1921 were together in the same datasheet and this was the example circuit on the first page.

Hence for the PCBA, we had a small run of about 30 boards with the issue (MAX1920 was populated instead of the required MAX1921). I needed to find the easiest way to solve this problem.

I compared it to the MAX1920 circuit and realized that the difference was only a single resistor to ground.

I did the calculations with the datasheet formula.

And I modified the schematic like this.

The issue was "how to solder it together?". The designer didn't expect to have any issues for this simple power supply circuit so this block was designed to use the smallest package-size.

I thought it carefully and settled on an 0805-size resistor. My final modification looks like this.

About 2 hours of soldering and less than $1 of resistors, I managed to save the day.

Much cheaper and easier than ordering replacement ICs!

Being from biomedical engineering field, we are always on our toes to maintain and repair the medical devices. Back in 2017, when Covid wasn't a thing. I got an opportunity to repair a ventilator. The reason why a ventilator is mostly repaired because it's one of the costliest devices used in a hospital. Although, they generally order 2-3 ventilator unlike the current situation. The challenges that one faces while repairing is the hardware. It is very heavy which makes it difficult for people to remove it, repair it and fit it back. Definitely a great experience. I made sure that a person around helped me to get the hardware component outside the ventilator and then I could repair it, clean it and fit it for the very next use.

A great fix there. For a technology that is so mature I'm surprised relays are still often the culprit in faulty electricals - weak hold on, stuck shut etc. At least you found your replacement part. There was something to be said for the relay sockets with the retaining clip to allow easy servicing rather than the solder through....but all down to mass production and costs and 'progress'.

I don't have an electronics background past what a mechanical engineer would have received 40 something years ago - I remember the text for the 2nd year course we all had to take still had vacuum tubes in it .  So while there are the usual fixit things that crop up from time to time at home I only have one work related story where I solved the problem.

Many years ago the industry I worked in was making the changeover from pneumatic control and pen recorders to electronics.  I was on a start-up for a new highly instrumented facility where we were about to do testing on a large system, part of which was remote to the control room.  The instrument techs were finding it impossible to keep everything calibrated (the facility was in fact over instrumented and untested in our use) and couldn't be bothered to maintain the sensors key to my tests because they were concentrating on keeping the facility up and my stuff was secondary.  There were still level gauges, pressure gauges, and temperature readout locally though.  I fixed the problem by flying a junior engineer from the home office in and stuck him out at the remote location with a notebook and pencil to make recordings.  Every once and a while I took him food and drink and made sure he was awake.  Problem solved 

The sweetest repair I did was repairing two monitors. A friend gave them to me and I could keep them after the repair. During that time I was student and buying extra monitors were not in my budget. I could really use those monitors.

After some googling I found they have a very common problem that some of the capacitors on the power circuits fail and replacing them was easy and cheap. And that was it. They started working smoothly after changing the capacitors. I used them for 3 more years until I left the country and gave them to somebody else.

The most satisfying electronics fix was while I was still in college, circa the late 1970s. I had a new girlfriend and went to her parents home to visit for New Year's holiday. 

She had a problem with her stereo record player with the left speaker output dead.

I was called on to save the day. 

At the time, I'm studying to be an EE, I'm usually broke, my toolkit was minimal, I carried with me a really cheap analog VOM and cheap soldering pen.  There were no schematics.

I made some readings while explaining my diagnosis with the most flowery of impressive EE jargon I can muster (probably throwing in some calculus jargon too) , closed my eyes,

and made my best guess to what failed. I coped the IC number down from the silkscreen on top. She calls electronic shops in town and finds one that has the part.

NOW THE PRESSURE IS REALLY ON !

MY REPUTATION, MY FUTURE, FREE BEERS AND THE POTENTIAL FOR PHYSICAL ADORATION IS ON THE LINE.

She drove me to an electronics shop to pickup said replacement part, an audio amp IC.

The replacement process was a bit of a butcher job under the circumstances, but the IC got replaced while she anxiously watched over my shoulder.

The moment of judgement had arrived.

She stood by wide eyed in anticipation as I plugged in the stereo and turned the power knob to ON.

I'll admit I was the most surprised person in the room when that device is fired up, now working like new, rockin' and rollin' with some ELO, STYX and Eagles.

I am the hero of the day, skilled & intelligent, almost magical. I am a kid with a bright future (husband material), unashamedly garnering thank you hugs and cold Molson Goldens. 

Personal satisfaction and pride rode high in the saddle that day.

40 years later, I still troubleshoot and fix equipment ......( equipment sometimes worth millions of dollars and possibly affecting a large number of people).

I still get the same exhilaration when the equipment is brought back to life, not because of the impact to others, not because of the cost, just because I was successful.

It just feels good, a pretty common theme with the E14 community.

My best repair by far is when I fixed my vacuum's cleaner motor by replacing a burned triac... with no prior experience home appliances electronics back then, but with help of youtube I was able to identify and replace the broken part successfully!

My best electronics fix wasn't a big feat, but it was one of my first. My computer kept crashing and I was looking for a solution. I tested the motherboard and other components and eventually realized it was the fan. I was able to replace it for under $20. This was the first time I had even sen the inside of a computer, so I was pretty proud of myself.

Here are some of my best electronic fixes:

1) HP Pavilion Laptop: Due to overheating, the laptop faced a BSOD. Had to open the laptop, disconnect the motherboard and reflow solder the whole GPU, this has been one of the most delicate fixes I have ever done.

The fix was done after applying a pea-sized flux near the GPU and then blowing the hot air using the gun at 220 degrees celsius for max. of 30 seconds such that the flux flows inside and solders the GPU back into the motherboard. Guess what? It worked!

2) PC Fix: The processor fan wasn't functioning, had to replace RAM and then apply the thermal paste and replace the heat sink with a fan above the processor.

3) Micromax Canvas Doodle 4: The battery bulged, performance reduced. It was a non-removable battery. The screws were so tiny! Yet I assembled it with the new battery everything after a successful teardown.

4) Butterfly induction stove: Had to just clean the PCB where a cockroach was short-circuiting a point!