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Entry  Thu Jun 4 20:54:40 2020, gautam, Update, SUS, MC1 Slow Bias issues 
    Reply  Thu Jun 4 21:32:00 2020, Koji, Update, SUS, MC1 Slow Bias issues 
       Reply  Thu Jun 25 15:11:00 2020, gautam, Update, SUS, MC1 coil driver resistance quartered MCF.pdf
          Reply  Sun Jun 28 15:30:52 2020, gautam, Update, SUS, MC1 sat-box de-lidded 20200628T144138.jpg
             Reply  Sun Jun 28 16:29:58 2020, rana, Update, SUS, MC1 sat-box de-lidded 
                Reply  Sun Jun 28 17:36:35 2020, gautam, Update, SUS, MC1 sat-box de-lidded 
                   Reply  Mon Jun 29 11:55:46 2020, gautam, Update, SUS, MC1 sat-box de-lidded SatBoxSwap.jpg
                      Reply  Mon Jun 29 20:30:53 2020, Koji, Update, SUS, MC1 sat-box de-lidded 
Message ID: 15438     Entry time: Mon Jun 29 11:55:46 2020     In reply to: 15436     Reply to this: 15440
Author: gautam 
Type: Update 
Category: SUS 
Subject: MC1 sat-box de-lidded 

There was no improvement to the situation overnight. So, I did the following today:

  1. Ramped bias voltages for SRM and MC1 to 0, shutdown watchdogs.
  2. Switched SRM and MC1 satellite boxes. The SRM satellite box lid was opened, while the MC1 lid was left open. The boxes have also been re-labelled lest there be some confusion about which box belongs where.
  3. Restored watchdogs and bias voltages. Curiously, the MC1 optic now only requires half the bias voltages it did before to have the correct DC alignment for the optic. The Satellite box is just supposed to be a passive conduit for the drive current, so this is indicative of some PCB traces/cabling being damaged inside what was previously the MC1 satellite box?

IMC is now locked again, I will monitor for glitching/stability.

Update 6pm PDT: as shown in Attachment #1, there is a huge difference in the stability of the lock after the sat box swap. Let's hope it stays this way for a while...

Quote:

I'll leave the MC1 box open overnight and see if that improves the situation, and if not, I'll switch in the SRM satellite box tomorrow.

Attachment 1: SatBoxSwap.jpg  1.020 MB  Uploaded Mon Jun 29 19:38:15 2020  | Hide | Hide all
SatBoxSwap.jpg
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