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View Full Version : Opportunity To Buy a Cheap Non-Working Altair 8800



Bungo Pony
March 5th, 2017, 02:56 PM
I've come into a situation where I may be able to buy myself an Altair 8800. The only catch is... it apparently doesn't power up.

Since I'm not afraid of tackling electronic problems, I'd like to have a look inside the machine before I decide whether to buy it.

Is there anything typical that goes wrong with the Altair 8800 that causes it to not power up?

snuci
March 5th, 2017, 05:54 PM
I hope you got that one. I was trying for that myself (remotely) but it just sold.

I would just start at the power supply and check the voltages. Might be capacitors or something simple but the original owner had schematics on CD so I imagine they would have checked the simple stuff first.

glitch
March 5th, 2017, 06:00 PM
It's basically a good looking blue box full of bad engineering decisions. Which revision will hint at which bad decisions were made, but what's inside can be completely different/random than a "stock" configuration. I say "stock" since most Altairs, especially early ones, ended up with a mix of boards depending on what was available at the time and what fit the user's needs the best.

"Not power up" could mean any number of things. It'll probably need recapped, especially if it's an early machine with the handful of axial electrolytics on a PC board (later machines had a single large soda can sized cap for the +8 rail). The individual boards may also need recapped. I've received machines that I'm almost certain never actually functioned, so it could be some basket case like that.

"Cheap" is also relative. If it's in good cosmetic condition and under $1000 it's probably a good deal.

Bungo Pony
March 5th, 2017, 06:15 PM
I hope you got that one. I was trying for that myself (remotely) but it just sold.

I would just start at the power supply and check the voltages. Might be capacitors or something simple but the original owner had schematics on CD so I imagine they would have checked the simple stuff first.

Ah, so you're the guy in Ontario!

Yes, I bought it. I took it apart while I was there. It's a bare bones model, and it's an easy fix. Theres a broken wire inside. I'll need to replace the caps as well since they're a little crusty

snuci
March 6th, 2017, 12:20 PM
Congrats! That was a very nice machine and the "bare bones" model is a plus on these. It would have been a steal for twice the price but I can't compete with a local :)

Bungo Pony
March 6th, 2017, 12:45 PM
Congrats! That was a very nice machine and the "bare bones" model is a plus on these. It would have been a steal for twice the price but I can't compete with a local :)

The thing that surprised me is that it was local. I would have expected something like this to pop up in Ontario. There doesn't seem to be much interchanging of vintage computers in this province.

Apparently there were others who were interested in it. I was going to look at it the next day, but he told me I should call first because he had a lot of responses and it might be gone by then. So I figured I'd jump on it and went to see it that night. The guy was just selling it for his uncle who was the original owner who had purchased it in the USA.

I took it apart while I was there. After opening it to look inside, my GF exclaimed "there's nothing in it!"

This is an entirely different beast for me to indulge in. I've never owned a computer that was older than me, let alone one that doesn't have a screen nor a keyboard.

glitch
March 6th, 2017, 12:50 PM
Welcome to the lights and switches club! They're fun to play with, at least I think so -- front panel machines in general, S-100 in particular.

snuci
March 6th, 2017, 12:58 PM
The thing that surprised me is that it was local. I would have expected something like this to pop up in Ontario. There doesn't seem to be much interchanging of vintage computers in this province.

Actually, you'd be surprised what's out there in the prairies. My Amiga 3000T came from Saskatchewan and I know I've bought stuff from Alberta before. They tend to be around universities (probably surplus). I has something with a SAIT sticker on it once. Some time back, I knew some people from NAIT and would have loved something from there. The 3000T came from USask, if I recall correctly.

Bungo Pony
March 6th, 2017, 03:10 PM
I've bought stuff from Saskatchewan and Alberta before, but when it comes to Manitoba, things seem a bit dry. The Altair absolutely knocked me off my chair.

Manitoba's always been like that though. I think it was the first province where the BBS scene was completely dead whereas other provinces still had quite a few boards to call.

Marty
March 7th, 2017, 04:04 AM
Hi All;

Bungo Pony, Congratulations !! Welcome to the club of Altair owners..

What Boards are in it ?? Pictures Would be of Interest and or help..

Since all is unknown about Power, Pull ALL of the Boards and Disconnect the Front Panel before first Power up..
Use an Old fashioned Light Bulb in Series to the input Plug and some kind of a Dummy Load on it's output..
You will save Yourself alot of grief if You do this..
Replace the Capacitors, check all of the Diodes and if your model has any Transistors or Replace them and You should be good to go..
Check for any burning on the Transformers, unlikely, but a good thing to do..
Measure Your Voltages, if Your load is very small Your voltages might be high..

THANK YOU Marty

Bungo Pony
March 8th, 2017, 02:18 AM
What Boards are in it ?? Pictures Would be of Interest and or help..

The only additional board in it besides the CPU is a 4k RAM board. I was in the process of getting some pictures up, but something that requires my immediate attention has popped up in my life.

As for the power, I'm pretty sure the broken wire going to the CPU board has something to do with it. I'm probably not going to restore it until Fall, since Summer's coming and I have home renos to do this year.