29 Jan
2024
29 Jan
'24
10:43 p.m.
On 2024/01/29 12:45 p.m., William Sudbrink via cctalk wrote:
Sellam Abraham wrote:
I had a chat with an electrical engineer about discharging old picture
tubes many years ago, and he highly recommended using a suitable
resistor array - like a HV probe to drain the charge on B&W monitors.
Particularly ones that had a separate HV diode. He told me that
discharging with a screwdriver can pass too much current (caused by a
cascade of charges) through the diode array and damage them.
This explained a problem we were having with B&W XY monitors made by
Electrohome and Wells Gardner where the diode that was mounted between
the HV transformer and the picture tube would fail and run hot, over
heating the silicon rubber caps on the ends. I've not lost any HV diodes
on machines since using our HV probe to discharge since that time.
John :-#)#
--
John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
Call (604)872-5757 (Pinballs, Jukes, Video Games)
flippers.com
"Old pinballers never die, they just flip out"
I think you were fine. That's how you
discharge them anyway. You were just missing the grounding wire :)
Yes, I have one
set up for just that purpose. Wire clamped to the shaft with an alligator at the other
end.
But I was so pissed off, I just grabbed a screwdriver off of my workbench. I'd
rather not be the electron sink
In this case. I've never taken a hit off of a CRT have you?
Bill S.