TNP #39 - Faxitron MX-20 Digital Micro-Focus X-Ray Machine Teardown, Repair & Experiments 

Wow you fixed an awesome piece of lab equipment by replacing a little reed switch. I remember a company called the Electronic Goldmine having those reed switches for a buck a piece in the 1990s. Awsome work ❤

Nice teardown and explaining, as always. Here's an interesting idea for you - what if we take, say open LTZ1000 reference module (or other zener), place it in the chamber for picture, and apply power and measure zener with 3458A with fast sampling rate. And then take number of pictures with different x-ray voltages and see if that affects or shifts the zener value in any visible way. Could be interesting to know, if zener output might shift from say shipment security checks at airports too, even without applied power to chip...

Thank you, Shahriar, for another great video! These little faxitron units are really good for imaging small items. Many of the x-ray units use a basic two element tube, where the focal spot size is directly proportionate to the filament dimensions. These models use a tube with a biased focal spot. By changing the bias voltage on the focus element, you can adjust the focal spot size down to very small diameters (I think these units are set to .02 or .03mm). We call those "microfocus" tubes. The gun board produces the bias voltage for the focus, among other things. In 1999, I went to school for a new cardiac cath lab system for imaging the heart that used a new type of variable focus x-ray tube. It could achieve focal spot sizes not quite as small as this, but at voltages of up to 150kV and current of up to 1000mA. It was quite the system! Anode cooling was a big issue, as you can imagine! It also used an image intensifier (dynamic DR panels weren't available yet) and the image intensifier had a variable zoom that could track with the focal spot. I foget what the marketing name was, but it was very complicated and expensive and we only sold a few of the units. Thanks for sharing and bringing back some memories!!!

Nice tutorial on the X-ray tubes and how they work, I had no idea....but now I do! Thanks.

I love how simple you make troubleshooting a device like this. It's illustrated to me how important it is to understand, at least to some degree, how the thing you're working on actually works. Certainly possible to repair things without that knowledge, but that combined with a step-by-step approach makes for a very efficient diagnosis that would otherwise take much, much longer.

AH! You do have some FINE pieces in your collection! The old Triplett 630! :)

X-ray Shahriar-B. Casual genius.

Another great video. Teardown video for high-voltage devices are worth to watch just like your RF related repair / teardown videos. Thank you!

Very interesting. I worked for Philips Medical System in Hamburg, Germany on X-Ray systems in another life. Back then instead of USB, control functions and UI were over CAN buses. Thanks for the trip down memory lane.

wow, the end result!

I appreciate the way you break down your troubleshooting approach. That's something I always struggle with.

What a video! There is no screen wide enough to fully display your genius!

Hats off to your level of intellect and vast knowledge. Every repair you do you is spot on with fault stage and components to be replaced. Thats called a Mervelous Electronics Engineer.

This brought back some memories of when I was a BMET. I loved that job. Best in the Navy as far as I'm concerned. Thank you!

Loving the cat flap for Pooch! :)

Wow, amazing equipment you have, and know how to fix it, and presentation is really good!!

Excellent video.

I think I would have been inclined to soak test the reed switch and try to prove that it has an intermittent operation on one contact. Only then can we be sure that there wasn't some other intermittent fault which has been disturbed into working for now.

going even further up in frequency

Absolute excellent video. I was always waiting for looking inside such a nice device. Here in germany e,.g. europe its very difficult to get a permission for such a device to be used officilly in a small lab even if it completly in housed. -- I worked with x-ray machines with up to 200kV at helmholz in a huge housed shield for experimenting with x-rays, focusing is a tough topic most mechanically done. At helmholz also gamma readiation devices are available.... I also tested pulsed radiation in medical applications (for example used ct) and detectors using ccd array (had a patent on this measure principle tests on up to 2000 Gy/h using a iPhone/Android) -as the film dosimeters are problematic - I like this topic really very much. And great of PCB checkout usually have to use a external service company on this at the moment when needed in my lab.

A very good video.

Worth mentioning that x-rays can also be 'filtered' by using inserts in the window of various materials. These are often used in mammography to help isolate specific xray energy levels to minimize dosage. The same goes for the anode, it doesn't always have to be Tungsten. A smaller machine like this likely produces lower energy xrays so you can also get away with steel shielding instead of having to step up to lead.

great video love stuff like that

Amazing device...

Awesome...cheers!

That reed relay (or maybe an adjacent one) also failed in my MX20, leading to current adjustment not working. Also gets super hot. Bought a replacement for K1 and U1, but haven't had the energy to install it yet (it's not a big enough problem to solve asap). Interesting that we had the same failure modes. If you're interested, I have the schematics for it.

Thank you for showing us such a great machine.

Absolutely love your channel. Your content is such top notch, and your knowledge is impressive to say the least. Any thoughts about doing a teardown of the Airborne Weather Radar antenna in the radome of airplanes? That seems like a crazy piece of engineering and I've got no clue how it works. Seems like it'd be right up your alley in terms of RF antenna and systems engineering. Just a thought, keep up the great work!

Great video! I always wanted to see that machine, it takes really nice pics. I was very curious to see the photo sensor. Maybe for a future video?

Given that the current through the reed relay is likely small, maybe the relay is below its wetting current? If so, running some DC current and exercising the relay might restore operation. That said, I am not sure if hermetically sealed glass envelopes enclosing reed contacts might prevent this wetting issue? 🤔🤔

For a second I thought that Mikeelectricstuff got a new x-ray or something 😂 ;) Nonetheless I'm always happy with video from The SignalPath too!

Heh i love that you had it x-ray its own broken parts.

Great timing! Just days ago I needed to see inside a potted module and asked a dentist friend to scan it for me (bonus, he did a 3D scan in addition to 2D, very handy!). Naturally, now I want my own X-Ray machine. This MX-20 looks like it does a good job, but when I am looking at buying one, it's not clear to me if the X-Ray sensor is included, what should I look for when buying one? Those of you that have experience in this area, any other units I should consider? I might roll my own (or adapt a dental x-ray), but there are obvious drawbacks to going that route. Thanks!!

Thank you for another awesome video, dude! The amount of expertise you posess about virtually any aspect of the matter is truly amazing. An unrelated noob question, tho. Today we have a tons of cheap microwave DIY solutions - human presense radars and similar devices with around $5 boards with smth. like LD2410 chip, so it's very tempting to play around with them. And the question is: what entry level hobbyist oscilloscopes, like up to $500, exist for those frequencies, like with the bandwidth of 25 MHz+ accordingly?

While the REST of the world is toying around with Laser Diodes, TSP once again ups the ante by playing around with his 'personal' X-Ray machine. Meanwhile, people at MY level are ecstatic that we were able to fix that faulty / intermittent flashlight!

I would love to work with a device like this at some point

If only you had an extra one of those high voltage DC-DC converters to x-ray.

Hi Signal Path. I watch and enjoy your many technical videos regularly. This particular one was most interesting because I have an immediate use of one of these now. I notice a few available on the market, but that brings up the question, what is really needed as auxiliary equipment and software to use one of these?? Any comments will be much appreciated. I see a few others with similar questions in these comments. Regards.

Excellent video

That AirPod X-ray looks extremely cool, it would be super neat to have a animation of it rotating. How long does taking a picture take start to finish, would making an animation of a few dozen frames be feasible?

Thanks again for a inspiriting episode. Always a pleasure and interesting to watch. Do you have experience in Thermal Interface Materials in electronics and test/measurement equipment for thermal conductivity? I would love to learn more on the subject. Kdrgds

Nice thinking! Probably arc pitting on the reeds from switching the primary of the DC to DC converter. I wonder if there would be any way to mitigate that, perhaps a mercury wetted reed relay?

So a reed switch was the cause, unusual.

Question: could the reed relay be replaced with opto coupler's and/or FETs instead? Solid state device should be more reliable. Its only switching 12V for the DC DC converters, isn't it?

18:03 I would assume the reed switch package is configured with both NO and NC operations (Normally Open / Normally Closed).

Thanks. I would love some details on the sensor/detector. Can you refer me? thanks, - Jim

Windows XP.... woah...

The air pod was quite "blown out" - can the machine (or you manually) do something like exposure-stacking to get a complete image with more details ?

Serious question what do you need so many SMUs for? That’s a pretty big pile

Very cool! Question, did you provide any proof of being a licensed X-ray tech or operator to buy it? I really want to buy one of these old X-ray machines for PCB reverse engineering, and I even tried to bit on eBay, but was contacted by the seller almost immediately asking for proof of state license since it's FDA regulated to show that I'm allowed to own one. How did you get a hold of one? Can you please explain? Thanks !

Looks like the relay was it. maybe you can test the relay too prove it.

Hi thank you. What kv range is that x-ray operating in?

I was wondering what KV range this x-ray machine operates in?

please create 3D Pictures ;)

I givem about a decade.

I hope a smartphone with a micro-X-ray device will soon come onto the market that can be used to examine smaller things.

It sounds like the filament is getting old and needs to warm up to full charge.

I've been watching the news to see how many gen-z members received the Darwin Award after this video but I could find find any... Then, I remember gen-z have no money :) Silly me!

I doubt you'll ever find a spinning anode in a Faxitron. Those are for x-raying fat people and making video at high frame rates.

And….. a real repair or is it a connection again 🫣😂