Why don't I listen to my own advice?
Popped in to see a client who is also a great friend for a coffee. Whilst rabbiting about all sorts of things he said he wanted to upgrade the memory and also his hard drive - no worries sez I and has the back off the system to check what the RAM is before you can say 'don't be a pillock'.
Stick the RAM stick back in again and it won't boot because it can't find the boot drive.
Off with the back again and find I have pushed the power supply for the boot drive to one side (would not have happened with a molex - I hate these SATA connections!) - pop it back on again but still no go.
Stick a new SATA signal cable on and it works.
Just not my day today - unable to work this morning as a thunderstorm caused a power cut (outage to you across the pond).
Motto - listen to that little voice....

I know how you feel. I have experienced a good few cases where I have offered to help a friend out with their PC, only to make (through some cosmic intervention) the situation a whole lot worse, usually through assorted hardware failure.

And that damn saga rolls on - the fault turned out to be the SATA power lead which had cracked and no longer fitted nice and tight. That memory - the so called match from Corsair turned out to have different latency so did not work. Sheesh - where will it all end, I ask myself...

It will only end when we go full circle back to the Abacus !

Mr. Lionheart;
I enjoy your articles and think too many of todays techies never had to deal with the old hardware that didn't always work right even when nothing was wrong. In so many ways hardware has gotten a whole lot easier to work with (plug and play and such) not having to set a jumper for everything!

Ah Jumpers - I recall trying to fix a bad motherboard only to decide to chuck it. In those days we used to keep the spare jumpers and as I pulled one of them off I noticed there was no metal insert in the thing - just a plastic cover.

No metal insert in the jumper is not unheard of..
Now, before using one, I always check.

We have had more bad luck on SATA cables, even good ones, than one has a right to expect. They must all be made in the same ELF factory.

The SATA cables with a click connect seem to be more reliable that the ones without - but I cannot always get hold of these when I need them.