I received a new addition to my collection today - a Dragon 32 computer. Bought as "Untested", but thought I'd have a gamble since the price was better than what most of these sell for lately.
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First thing I did was to open it up, disconnect the power connector from the motherboard and then test the output power from the power supply & AC adapter with my multimeter. 0v, it was dead! As I'm in the UK I thought I'd check the fuse in the plug and discovered that the fuse was missing. I replaced the fuse and then I checked the output DC voltages from the motherboard ribbon cable side, all present and correct: 12V, 5V & -5V.
With the correct voltages being output, I reconnected the power supply to the motherboard and powered on the computer. It didn't boot, just displayed an orange screen full of @ symbols.
Luckily I've done some research in advance, as well as experiencing the Dragon/CoCo emulator and this screen usually happens if the ROM isn't present or not working properly. So I removed the socketed ROM chip, sprayed both the chip and the socket with some electric contact cleaner and reinserted the ROM. Turned the computer back on and the Dragon breathes fire once again, booted straight into BASIC!
The computer needs a thorough cleaning, but I've given it a light cleaning for now and have pretty much spent the day loading & playing games from a CASDuino. A few teething issues to look at with the CASDuino, since some games don't appear to want to load, but the majority of stuff has been fine.