Wizdeo Analytics

HP 7044A X-Y Recorder Restoration

Published on Sun, Jul 21st 2024 Science & Technology Rectangular HD

It takes another long video full of analog goodness to repair this X-Y recorder beauty, because we end up fixing it twice! We also rejuvenate the pens while we are at it, also using two different methods.

HP 7044B and 7045B Service Manual: https://archive.org/details/hp-7044-b-7045-b-x-y-recorder-operations-and-service-manual-07044-90006-nov.-1980

Stuff that supports the channel:
- Support us on Patreon: https://www.patreon.com/curiousmarc
- Amazon links for the tools I use in the lab: https://www.curiousmarc.com/amazon-links
- Channel merch on Fourthwall: https://curiousmarc-shop.fourthwall.com
- Legacy channel merch on Teespring (I don't have everything transferred to Fourthwall yet): https://teespring.com/stores/curiousmarcs-store

"Elevator Music" Credit: Crinoline Dreams by Kevin MacLeod

Our lovely sponsors
- PCBWay: fast turn PCBs, https://www.pcbway.com
- Electro-Rent: https://www.electrorent.com
- Keysight: test instruments: https://www.keysight.com
- Samtec: connectors: https://www.samtec.com
- R&D Microwaves: https://rdmicrowaves.com

Get more technical info on the companion site: https://www.curiousmarc.com
Contact info: https://www.youtube.com/curiousmarc/about

00:00 Intro, previous HP 7035B restoration
01:06 Inspection and first try
02:42 Disassembly, slide cleaning and platen repair
06:44 A power supply fault?
08:44 X-axis fix
09:30 Y power supply debug and fix
13:07 Y-axis still fails!
13:42 Servo circuits (with elevator music)
18:18 Y servo circuit debug
21:01 It self heals, then self breaks!
22:10 Bad op-amp?
24:55 Root cause, repair, and calibration
28:28 Restoring the pens
32:24 It breaks again!
34:02 Second repair
37:59 Laser L-I curve plot demo