This is the computer that reignited my interest in retro computing. My father-in-law was in the process of decluttering his house and came across a boxed Spectrum 48K in mint condition. I don’t recall the exact date, but it was around 2009. I’d owned a similar model back in the day, but it’d got thrown away many years ago, so was utterly delighted to own one again.
The only problem with it was that when I first plugged it in, it didn’t work.
I ended up taking it into work a couple of years later to diagnose, as I had all the tools there, including an oscilloscope. I’d already started a blog at that point documenting Z80 assembly software techniques, so figured it’d be a good idea to blog my repair.
This was one of the most protracted repairs I’ve ever undertaken. From original diagnosis to fix took around 8 years!
In addition to fixing the borked upper 32K memory block, I’ve also recapped it as one of the capacitors had shorted, taking out one of the transistors in the DC to DC power supply section.
It has also been converted to output composite video.