Hermes destroyed my Fluke PM3092

Preamble

Wikipedia states that Hermes is the god of commerce, as well as trickery and thieves (amongst other things). The latter two might be best to describe Hermes – the courier company. In fact Perses would be a more suitable name for the company, as he is the god of destruction.

I had purchased an absolutely beautiful Fluke PM3092 oscilloscope, and was really looking forward to receiving it. When it arrived, in fact before it arrived, before I had even opened the door I heard the delivery guy drop the package on the floor. “That doesn’t sound good”, I thought to myself. When I opened the door, I said, immediately and with a glare, that the package was an oscilloscope and that it needed to be handled carefully. The guy’s face fell. “Ah well”, he cried, as he departed, “Have fun with it!”

Continue reading Hermes destroyed my Fluke PM3092

Fixing broken Dell Laptop power supplies

Preamble

Following on from Dell M6700 or M6800, there are a lot of laptops sold without power supplies or chargers. This made me wonder:

  • Is it because they blow often?
  • Why is that?
  • Are they plugged into power hungry docks
  • Are they underrated?

See M6600 Owner’s Review – Warning – Large pics – Personal Opinions for an interesting break down of the power supplies and current draw.

Anyway, I thought that instead of buying an expensive new, or second hand, supply (the 240 W or 330W can go for up to £100+), is it possible to to fix them? Is there a common failure mode? A recurring point of failure?

Continue reading Fixing broken Dell Laptop power supplies

How to reverse engineer a PCB

Preamble

A colleague and I have been trying to reverse engineer a few different PCBs recently (a coin operated washing machine’s control board (see Reverse engineering the coin box) and a Bastl Trinity are a few examples) and we have been scanning them or simply photographing them, with the aim of either copying them, coming up with a schematic or coming up with a PCB mask, with mixed or limited results. Like this:

After watching EEVblog #675 – How To Reverse Engineer A Rigol DS1054Z, I saw that Dave explains a pretty good process, using a tripod mounted camera, light box and a back light.

Continue reading How to reverse engineer a PCB

Smok Alien 220W – Not charging

Preamble

Oh no! Yet another Smok Alien 220W problem..?!

On top of the other three issues that have had with Smok Alien 220W in the past (“No coil”, “Ohm too low” and simply refusing to boot), I have just started to notice another problem with one of my Smok Aliens. It will not charge the 18650 LiPos correctly. When the USB cable is plugged in, the bars on the main screen start to move, in the charging animation, but after a while, 5-10 seconds, the usual charging screen flashes up, but then quickly (<0.5 seconds) flashes back to the main screen again, still with the batteries charging animation. Again, wait 5-10 seconds and then the charging screen flashes, and so on.

If left charging, then the batteries actually discharge completely..!

It used to work fine, but then this issue appeared maybe a week or so ago…

Continue reading Smok Alien 220W – Not charging