Thursday, 31 October 2019

The joy of coincidence

Coincidence No. 1

Last weekend we reverted from Daylight Saving Time to GMT. It was GM4FVM's job to correct the clocks at FVM Towers. I did the heating clock, the shack analogue clock, etc. I couldn't do the clock on the oven as Mrs FVM was baking bread in it. I did the kitchen clock. I forgot the clock on the mantelpiece in the living room. I forgot one clock, just one.

Mrs FVM took  her time from the one in the living room, which was wrong (my fault). In the kitchen the kitchen clock decided to stop as soon as I corrected it due to a flat battery - coincidence 1. Just by chance, it stopped when I changed the time on it. The one on the oven just confirmed her view of the time - it was wrong because of the baking bread so I hadn't been able to change it yet.

So the FVM family tea had to be held an hour early, because everything had been prepared following clocks I hadn't fixed. Kitchen clocks that were stopped (I pointed out), or otherwise impossible to change by FVM, but he still gets the blame for those coincidences.

I tried to protest, pointing out that there is a clock in the kitchen on the radio which updates automatically, but then I was confronted with the evidence of the living room clock. Guilty!

Coincidence number 1a

Well, not really relevant to the radio blog, but I was on my way to see my ham pal "Gouda" at the garden centre tea shop the following day (what a crazy life I lead). I called in to get my hair cut by Chris the Barber in Duns. His clock was also still on BST - so not such a surprise at all really. This is just to show it isn't just me at fault. And radio amateurs do sometimes spend money on their appearance, despite what people say.

Coincidence number 2
What are the chances of these 2 drives failing at once? Or me misunderstanding the whole thing?

My shack computer has been suffering from over use. So I have replaced it. I might explain why and what with later, if anybody is interested. Or maybe I will explain someday even if nobody is interested.

As soon as I connected the backup drive to the new computer it failed. Exactly when I needed that drive, it failed. The click of death, that scourge of mechanical discs. What a mess coincidence number 2 was. Mind you, it did that once before and then it came back to life again later, but there is not much chance of that happening now, I thought.

I decided to use a different backup disk which had some of what I needed on it. Let us call the second one, backup disc 2.

Coincidence number 3

The new computer was acting up. It kept losing the USB sockets. I could not get through a complete backup without the transfer failing repeatedly.

I decided this must be due to a new 5 USB 3.0 socket extension card. However, I did have a 2 USB 3.0 one to try instead. I did not have enough of the right power sockets to run the only replacement I had and power the DVD drive at the same time so I decided to power the temporary extension card using a separate power supply. Could that cause some earthing problem? No, it seemed to work.

I climbed under the bench to try the sockets and suddenly there was a blue flash, followed by a loud bang and a nasty burning smell. I lay there and noticed that it was now dark, as the lights had gone off, and there was that sound of slowly stopping fans. I have described this sound before and it never leads to anything good.

Oh bother.

Please excuse the unparliamentary language. Jings, crivvens.

I had hoped that would be a nice new computer, but what have I done? Oh deary me.

Extricating myself from under the bench I found that I had blown the earth leakage circuit breaker on the main house fuse board, the switch fuse for the circuit covering the shack plus half the house, and the 10A fuse in my main "big switch" for the shack sockets. Probably I had blown the computer and everything else.

Having this blow loudly about six inches from my left ear made me a bit unsettled. Why had more than one fuse gone? Why the main earth leakage circuit breaker gone? Was this the earth fault I had feared?

It took me a while stop hunting for earth faults and remember that this had  happened before. One of those power supplies had blown in the same way a couple of years ago. Luckily that time I was not stretched out beside it. They are just cheap throw-away devices. So this was coincidence 3. I had decided to put my head right beside an exploding PSU, and it has decided to blow just as I did. And this had nothing at all to do with the USB extension board. Multiple coincidence.
This is the only one of three PSUs which hasn't blown ... so far.
After resetting the safety breakers and replacing the fuse, the computer powered up again.

But all the mains clocks had stopped and needed to be reset ...

Coincidence number 4

None of this solved the fact that the USB sockets still appeared to be failing. Connections to rigs kept stopping, my rotator boxes kept losing contact with their software, and all seemingly at random. It took a while for me to realise that it was not just that the second backup disc was failing as a result of the USBs going down, the second backup disc was causing the USBs to go down.

The second disc had decided to fail on the same day as the original backup disc, and even more puzzlingly, every time it went down it took the USB connections with it. Or at least the ones on the extension board. So that was coincidence 4.

It was easy to prove when I worked it out. Just introduce hastily thrown together backup disc 3, and everything was fine. So what are the odds of backup disc 1 and 2 failing at the same time? What are the chances of disc 2 having a fault that affected other USBs?

What are the chances of me completely missing the point and blaming myself?

I tried very hard to save that disc 2. I used AOMEI software to try to repartition it, format it, or whatever, but nothing worked. "Bad sector" stopped it whatever I did. Something is seriously wrong beyond bad sectors. I got the data off it by a three hour session of keeping pressing "retry" every time it failed.

So, when I stopped trying to use the second backup disc, the USBs all started to behave themselves. Then the postman delivered the cable I needed for the extension card and everything went back to normal.

Strange event number 1

Not exactly a coincidence, but after all this I tried the first backup disc again and it worked this time.


What a rigmarole. Certainly backup disc 2 would have proved to have failed whenever I tried it, but that would have been obvious if I was not trying to set up a new PC at the same time. I cannot trust the first disc but it is working again now. I spent ages with that extension board when there was nothing wrong with it, and my idea of an earth fault was just me trying to make sense of the temporary PSU blowing up spectacularly just when I decided to use it. Mind you, it had been sitting in a box for a couple of years, so blowing is not a real surprise - or so it looked when I calmed down.

When I was lurking under the bench in the dark, listening to the silence and smelling that awful burnt smell, I did wonder "why do I do all this?". I mean, here I am, in my sixties, stretched out on the floor in an awkward space, having just blown everything up (or so I thought). Will I ever mature and become one of those amateurs whose photo shows a clear desk, a rig and a microphone? Nothing ever blows for them, and their tea arrives on time in all time zones thanks to accurate clock regulation.

I would show you a photo of the blown power supply but I couldn't wait to throw it out. The photo above is the only one of three still working. No doubt it will blow soon too.

I have ordered a new case for a new backup drive (number 4), using a disc salvaged from an old machine. Maybe this is my problem, salvaging things and using them for years beyond their "use-by date". But hold on Jim, Backup discs 1 and 2, plus the PSU, were all bought new by me and are not salvaged at all.

Moral of the story?

Diversity and redundancy. Have two of everything. Or three. Then you can be totally mystified when they all break down together.

Or, to put this another way ...

If it can go wrong, it will. And it will go wrong just when you expect it not to.




1 comment:

  1. A interesting but very strange effect Jim. At least you found something but uncertain why it happened? I can't think of anything to would answer this but others might be capable of explaining? 73, Bas