M0JXD

M0JXD Electronics engineer looking to venture into the world of repair. HMU if you're in the Midlands UK and need something repaired!

Sometimes you can't win them all.Here are some pictures from an attempt to repair some Sony XM3 headphones. They would n...
15/01/2025

Sometimes you can't win them all.

Here are some pictures from an attempt to repair some Sony XM3 headphones. They would not charge and had been left for over a year.

The first issue I found was the battery - literally zero volts across it having been left so long. Bringing Li-Po's back to life is risky business, so in a new one went.

At this point we discover the real reason why they wouldn't charge - a destroyed USB port. So that was replaced too. Those SMD ports can be tricky, but no match for a Hot Air Station (let the jokes ensue...).

And after this, I also found that the ribbon cable between the main and USB boards had gone awry. If you research about repairing these it's another common issue. So a new one was also fitted.

Sadly all this did not fix the problem. 5V was now definitely on the board but still no dice, possibly parts had been fried by the bad port (or maybe it was something I inadvertently did). The last ditch attempt for one of these is to buy replacement PCBs, which would put the repair outside the desired cost. I did try contacting Sony for some more information and/or parts, but you can see how that went...

This is being posted because I want to emphasize that no matter what, I'll give it my best try! Luckily for the owner, these headphones still work when using a wired lead so they can still be used. From my perspective, it's worth it even for the practice! In situations like this, there is no charge, just time away from your broken gear as I give it my utmost!

These days most electronics devices have some form of computer in them. Having a fair knowledge of CS and being able to ...
06/12/2024

These days most electronics devices have some form of computer in them. Having a fair knowledge of CS and being able to program is immensely useful!

Here are some screenshots of a couple programming projects of mine. The first is a graphing application for Valve Wizard's Arduino Analyser (https://www.valvewizard.co.uk/analyser.html). It's made with Processing, an easy to use Java superset and was one of my first programming projects.

Next is of a component I contributed to the incredible DIY Layout Creator, which is written in straight Java (https://bancika.github.io/diy-layout-creator/). I've contributed a few components now, and have even made some video guides:
https://www.youtube.com/watch?v=a0dkfJJ4AgM&list=PLrKmpWTE8iQUW0RJYVDU6CNvc71-J55lI

I've also programmed in Python, C/C++ (I prefer plain ol' C though), Bash, and some ASM (for 6502 and PIC MCUs, x86 is baffling!). I'm also slowly learning other languages and have been working on some unreleased projects. Keep an eye on my GitHub if you so wish: https://github.com/M0JXD

Staying with the bio-sciences theme, here's another ÄKTA board. This time from a FRAC-950, another piece of equipment us...
05/12/2024

Staying with the bio-sciences theme, here's another ÄKTA board. This time from a FRAC-950, another piece of equipment used in chromatography.

Another case of two boards. The first board was a similar case to the to the P-900 boards in my last post, cutting out under the load of the motors.

However the second board was quite a different situation. It looked as if it had been the victim of a spillage, and had caused what I can only imagine to be a quite spectacular failure of an inrush suppressor. After carefully checking with an external supply that the damage was contained to the PSU section I got to work repairing the board and replacing parts. I had a difficulty with sparking occurring on startup due to the traces having burned out and being replaced with new wiring, but some careful cleaning, dremel work and insulative tubing put a stop to that. Both boards got a full recap for good measure too and are back in service.

Apologies for the quality of some of the photos - they're actually stills from a video I sent during the repair. The video ended up very compressed which sadly reflects in the quality, but they're good enough for illustrative purposes I hope.

Something a bit different, this is a board from a ÄKTA P-900.They're used for liquid chromatography in the bio-sciences ...
05/12/2024

Something a bit different, this is a board from a ÄKTA P-900.
They're used for liquid chromatography in the bio-sciences industry.

I had two boards to fix, both with the same fault. They turned on but would not drive the pumps, the units cut out under the load. Any electronics engineer worth their salt knows in equipment this old (these are from 1994 iirc, look at that old Hitachi H8 MCU) a first suspect is those electrolytic capacitors, and they simply could no longer deliver the juice.

Two recaps later and they were as good as new, no more outages! If you have old equipment with weird behaviour it's a good bet is that the capacitors have deteriorated (although I want to stress this is not always the case) . It's quite an involved process changing all the caps, 26 per board for these, but well worth it to keep your gear going strong into the future. With any luck these will last for another 30 years!

Now something a bit different to the music gear. You might have noticed my username is a ham radio callsign, so let's po...
05/12/2024

Now something a bit different to the music gear. You might have noticed my username is a ham radio callsign, so let's post some ham radio stuff!

These are snapshots taken from some videos I took regarding doing the the popular "HF Mod" on the well known hackable and budget friendly Quansheng UV-K5 radios. I'm terrible at video editing (and there are now a fair few guides on YouTube) so they never saw the light of day, but I did end up with cool handheld radio that can receive from Top Band to UHF! I was initially concerned I'd done it wrong as there was a ticking sound, but a few days later the main developer of the mod (KD8CEC) uploaded a new firmware as the ticking was caused by the S-Meter process, so now it works superbly.

The mod involves adding a sub-PCB, some trace cuts, some 0402 SMD component replacements and uploading the new firmware.

I'm happy to look at radio gear, doing repairs, modifications or whatever else you need 🙂

Some pictures of a keyboard that I repaired.Initially it wouldn't turn on, turns out that the wiring to the power supply...
05/12/2024

Some pictures of a keyboard that I repaired.

Initially it wouldn't turn on, turns out that the wiring to the power supply board was done very badly - they had been hot melt glued and had zero solder!

After that I found the keys were a bit sticky and the velocity aspect didn't work right, so a clean up job ensued. It works great now!

We'll begin with a project I did a couple of years ago, here are some pictures of my clone build of the classic SLO-100 ...
05/12/2024

We'll begin with a project I did a couple of years ago, here are some pictures of my clone build of the classic SLO-100 amplifier. You might be able to tell I'm a bit partial to valve amps!

I loved every moment and it's a wicked amp, but amp building is expensive so it's the only one for now! If you have an amp that needs repaired, modified (or built...) I'd be happy to help 🙂

Hi, welcome to my page!I'm an electronics engineer looking to venture into the world of repair. I've done stuff for frie...
05/12/2024

Hi, welcome to my page!
I'm an electronics engineer looking to venture into the world of repair. I've done stuff for friends and family in the past but I'd like to help more people bring a new lease of life to their electronic equipment!
I plan to operate on a "No Fix No Labour Fee", plus parts cost principle. As I'm just venturing into this world my rates will be very reasonable. I'm not a serious business as of yet.
I have some limitations in place - the main one being that all deliveries most be social distanced/contactless, because I care for very vulnerable people with poor immune systems.
I'm also considering expanding this page to offer other services I can do, such as guitar recording, programming, and maybe some tutoring.
Kinds of stuff I can repair: Music gear, audio equipment, lighting, solar equipment, retro games consoles, bio-sciences equipment... if it has a PCB, I'll have a look!
I'll be putting up some pictures soon of previous electronics/repair work I've done soon.

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Kettering

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