HP 9872T Trouble Shooting

[cruff]

(06-10-2018 02:11 PM)rprosperi Wrote:  Try joining then posting questions on the the Vintage HP Computer Systems group, found here: https://groups.io/g/VintHPcom.

The group is fairly active, and likely your best chance of finding someone with experience with one of these plotters.

I'm a member of that group also, I'll try to help out either place.

What happens when you follow the self test steps in the service manual section 2-23? Note that the self test switch in this section is internal, not the one on the back panel.