What’s that you say? More Astro Wars? Okey dokey then. Sit back and relax and I’ll tell you a story…
(And yes, yes I did give the main image an astro turf background!)
Not really a story
Just a little explanation of another repair job. This is the sequel to my other blog about the lovely Grandstand Astro Wars handheld: Astro Wars!
This unit was in immaculate condition, but utterly utterly dead. Nothing from the mains supply, nothing from battery power. I was fairly confident I could fix it, so I hit buy and waited patiently for it to arrive.
Yep, it doesn’t work
So this arrived a day or so later, and I can confirm that it didn’t work at all. So the first thing I did was take it all apart – while trying to remember (a) how it goes back together and (b) where I’d put all the screws.
So you can see in the image above that the joystick is bottom left, Start, Select and Fire bottom right and the main display up top. The first thing I did was break out the multimeter and try and trace the power coming in to the DC socket. Take note, it’s 6V with a negative polarity.
I could trace the 6V all the way to the left of where the power switch would be, no problem at all. Of course, without the power switch it’s impossible to test any further, so I used a crocodile clip to bridge from the red wire to the right side of the power switch. See the highlighted area on the picture below:
Next up, I checked to see if the 6V was still registering at the other end of this cable (below), which it was, so the issue must lie elsewhere.
While I was there, I also did a continuity check on all the connections. All good!
Astro Chores
So, we’ve checked that power is getting to the board. Checked all the connections. No signs of leakage or bulging on any of the capacitors. A quick check on the back of the VFD board, no dodgy solder joints anywhere.
You may be wondering what a VFD is. A number of handhelds like Astro Wars back in the day used this technology. It stands for Vacuum Fluorescent Display, which is nice!
Anyway, next up is the power transistor:
So I ran a continuity check on this, while still attached to the board. This showed a short-circuit between the Base and the Emitter, and I’m pretty sure that shouldn’t be the case. Anyway, I whipped the transistor out and tested it again to make sure.
Number Five Is Alive!
Here’s the power transistor in full close-up glory by the way:
So I set my multimeter as shown below and measured across the Base and Emitter (Base is pin 3 and Emitter pin 1 on the image above) :
This beeped at me, confirming the short circuit. Time to put a new transistor in and see if I can get this lovely Astro Wars game up and running…
It lives! So pleased with this one. Always good to test my limited repair skills, even better when it means rescuing a lovely bit of tech like this.
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