Remember that Seagate hard drive from the Amstrad Mega PC that decided to catch fire? Well, it’s finally back on the workbench! The culprit was a tantalum capacitor that managed to turn itself into a rather crispy mess, and I’ve been meaning to repair it for quite some time.

Thankfully I’d taken a photograph of the drive before everything went up in smoke, so I could identify the original component by comparing it with another capacitor on the board. Knowledge is power, after all! Without that photograph, I’d have had a much more interesting time working out what used to be there.

The burnt capacitor had practically fallen apart, with its innards spilling out and a nice collection of charred bits surrounding it. Out came the methylated spirits and cotton buds to clean everything up. I also decided to replace the other matching tantalum while I was there, since I’d rather not have another one decide to explode.

This little incident has rather changed my opinion of tantalum capacitors. I’ve been using them in various repairs, including the Macintosh LC 475, but their tendency to fail so spectacularly isn’t particularly appealing. I’m leaning back towards radial electrolytics for some of those machines.

For this job I’ve already got the replacement tantalums, so on they go. I’ve also switched to a 25 W soldering iron for this sort of work after a few unfortunate experiences with damaged solder pads. No need to cook the board any more than necessary!

With both capacitors fitted, it was time for a quick power test. No immediate flames! Excellent. Of course, to find out whether the hard drive actually worked, I needed to connect it to a computer with an IDE interface.

That gave me an excuse to drag out my old AMD Athlon 500 MHz machine, which I originally built back in 2000. It’s still got an assortment of cards installed, including ethernet, USB and a capture card. After a little rummaging around for suitable IDE cables, we were ready to go.

And would you believe it? The Seagate was recognised and booted MS-DOS 5.0! There was even some old software on there, including Wolfenstein 3D. I had a go at Monkey Island as well, although that wasn’t quite as cooperative.

Finally, I copied a bunch of files over to make sure the drive could still do something useful. Everything appeared to be working nicely, and there wasn’t a puff of smoke in sight.

One repaired Seagate ST3120A, back from the dead. No smoke and mirrors on this one!

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