powering up older machines - is it safe?

[Allison]

>
>Subject: powering up older machines - is it safe?
>   From: "John F. Kuenzig" <jfk at kuenzigbooks.com>
>   Date: Mon, 02 Jun 2008 18:21:02 -0400
>     To: cctech at classiccmp.org
>
>Hi all - I'm new to the list, been lurking for a while.  By way of 
>introduction, back in the 80s I was a bonified software developer (wrote 
>a mag tape locking device for an early version of UNIX back when there 
>wasn't such a thing, did work in telecom test equipment  and speech 
>recognition for years) but these days I'm in the old/rare book business, 
>technical books and all.  I like old hardware, though don't have the 
>storage space for much.  When I was in high school I took apart a Friden 
>computyper in my parents basement just to see what was in it.  Still 
>have the "core memory" board around here somewhere.  I've tried to 
>salvage manuals for old computers, component manufacturer technical 
>books,  and an IMSAI or two over the years.  Still have 20 boxes of old 
>components (everything from transistors, caps, resistors, etc to tubes) 
>in the garage I've accumulated over the years when I'm buying old books 
>from hobbyists - buried deep enough I don't even remember what's in them.
>
>Anyway, a friend asked me to try and sell a DEC Robin for him (he tells 
>me it's a DEC VT180 with a separate drive unit that he tells me was only 
>available to DEC employees), and my question is this:

;) have a few of them around.

>
>Is it safe to try and plug this machine in and try to power it up?  I've 
>seen various discussions about old capacitors dying, etc but I'm not 
>sure if this machine is old enough to worry about.  My plan was to try 
>and power it up (my consignor also gave me some software with it, not 
>sure if it's related or not yet), and see if it still ran ok, take some 
>photos for the group (if anyone wants to see it) and my own records, and 
>then try to sell it.  It appears to be in good shape, in the original 
>boxes, "monitor" in one box w/keyboard (looks to be a VT180), and a disc 
>drive unit in the other.  My consignor said it ran the last time he had 
>it out many years ago.  I've always enjoyed and preferred photographs of 
>old machines with their startup screen displayed rather than a dark 
>screen.  Seems like they have more life with a live screen.

Generally yes in my exerience. The PS is a ASTEC switcher in the drive 
and DEC in the tube/system case.

Customer could buy the second drive though when it was being sold it was 
very expensive.

>Any pointers appreciated (on or off list) - what to do or check in what 
>order would be great.  Its been a long time since I blew up directional 
>capacitors in lab...so long I don't even remember what they're called.   
>Thanks in advance!<grin>

Generally every one I'd found powered up or was dead.  The latter was
"it was dead when I got it" from the person before me and likely dead 
from the person before that.

Watch the VT100 monitor board.  There is a cap that should be a higher
 voltage part that fails in time taking parts.  It's repairable if croaked
but people panic when they see chared board.


Allison

Framingham,MA exdigit.


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