Problems with IBM 5150 Power

[Tony Duell]

> >    I find it unfathomable that people would actually use "tools" like     
> > this.
> 
> And that includes the battery.
> 
> It depends--I've got a couple of these that I'll toss into a toolbox 
> if I'm looking for a quick reading or continuity test.  If it gets 
> dropped or eaten by a dog, no biggie.  The Fluke stays home.

My Fluke goes with me. It's rugged enough to stand up to minor misuse 
like being dropped (I forget what the spec is for dropping it with the 
protective band round it, but it's quite a height). 

> 
> If someone needed only to take a few readings and didn't have a meter 
> of any kind, I'd have no problem with him using one of these, 
> particularly if he first did a "sanity" check (e.g. check the voltage 
> on a new carbon-zinc cell to see if it was somewhere around 1.5v and 
> perhaps checked a known good resistor or two).

A freind of mine was nearly killed by a cheap DMM. Unknown to him the 
range swithc had developped a bad contact and would intermittantly read 
far too low. He checked the voltage on some mains wiring he was working 
on, it appeared to be dead. He touched it. That's when he found out the 
meter was malfunctioning.

Yes, I know you should check on a known live point, then on the circuit 
you're working on, then on the known live point again. IIRC, in this case 
the meter was intermittant and had given good readings a few minutes 
earlier so he assumed it was OK.

The first outcome was he was thrown backwards by the shock. The second 
outcome was that he bought a Fluke. 

-tony