Re: Tektronix 7b92a shuts down crt & graticule illumination on 7904 mainframe
If I remember correctly there is a separate small 5V rail especially for the lamps and lights. You have to add the connections for a 7603. As it does not have it. Most likely this is what is being dragged down. It wont effect the scope. I have bad news on the trigger light though If I remember correctly that is driven from a custom tech IC. I had one of those burned out in an A plugin it did share the IC with a 485 of which I had a parts unit for. If you are looking for shorts on the main 5V supply I do not think you will find them. At least for the lamps.toggle quoted messageShow quoted text
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Dave Daniel
Sent: Sunday, February 7, 2021 1:43 PM
Subject: Re: [TekScopes] Tektronix 7b92a shuts down crt & graticule illumination on 7904 mainframe
Ummm... I’m not sure hot-plugging a 7xxx plug-in is a good idea since they were not designed for that. The result will depend on the sequence of contact between the plug-in board fingers and the 7904 connector contacts when the plug-in is inserted (hint: they will not all make contact at the same time).
All hot-plug systems of which I am aware have different length pins/fingers which serve to control how the circuits on the hot-pluggable board are activated as well as active circuitry to protect things during power-up.
On Feb 7, 2021, at 12:07, firstname.lastname@example.org wrote: