23 Jun
1999
23 Jun
'99
3:54 p.m.
On Wed, Jun 23, 1999 at 11:22:23PM +0100, Tony Duell wrote:
In my experince (at last count I have 5 of the little
machines...),
most HX20 problems are due to bad connections. Have you reseated the
tapewire connectors between the keyboard and the CPU board and
between the display and the keyboard?
I'll have to bring the whole unit into the lab tommorow and try it
all.
_NICE_ toys :-)...
And I didn't even mention the brand new Tektronix colour LCD
oscilloscope, or the Ritek computer-controlled ultrasonic pulser
(which I'll be programming this summer). :)
My personal equipment (an HP 184A, broken, and a Radio Shack
multimeter) pale in comparison. Of course, mabye I would have more if
I actually knew how to use them...
[more tips which I'll be investigating tmw snipped]
I have the hardware manual for the HX20 - it's
really a service
manual and includes schematics, etc. Let me know if you want me to
look things up. From what I remmber, the PSU is quite simple, and it
depends on the NiCd pack to set the voltage on the (nominal) 5V
line. There is no 5V regulator in the machine.
Oro? That seems a bit funny -- the components must be really good at
handling over- and under-voltage, then. From what I remember, the
voltage of NiCds drops really fast when the battery is low.
--
Brad Ackerman N1MNB "...faced with the men and women who bring home
bsa3(a)cornell.edu the pork, voters almost always re-elect them."
http://skaro.pair.com/ -- _The Economist_, 31 Oct 1998