Saturday, June 16, 2012

diagnosed Katrina's rebooting HC

Katrina reported some trouble with her Skywatcher SynScan telescope. It seemed that the hand controller was randomly rebooting on her last night.

In the GBO, we checked the Registered Jack connections at the mount and the hand controller. They seemed OK. But immediately—it was obvious—that there was a problem with the power connector. If you brushed the cord or touched the L-shaped plug, the mount (and hand controller) briefly lost power. I wondered if it was a broken connection, cracked solder, or a cold solder. Let's open her up!

We removed the plastic cowling, disconnected the two jumpers, and removed the printed circuit board from the inside of the cover. Damn. Didn't have my repair kit with me. And, in particular, didn't have my close-up specs! Took us a while to track down a magnifying glass. While it was firmly in place, I didn't like the look of the solder joints on the PCB. So I reflowed them.

Reinstalled the board and hooked everything up. The problem remained. Damn. It was a bad plug. Visibly loose. Note a good design. I complained that manufacturers didn't seem to consider that a telescope might be used in different places, set up and torn down frequently, cables connected and disconnected often. I showed her the robust screw-in power kick-proof connector on the Paramount. Skywatcher used the cheapest connector; Bisque used the good one.

I recommended the next step was to change out the connector. Something completely different that would tolerate vibration and movement and kicking (in the dark). I had an automotive 2-conductor quick-disconnect plug in mind... I was sure I had a spare at home.

In the meantime, I showed her a trick, coiling the power cord around the nearby handle.


Repaired her power problem by changing to a different type of plug.

No comments: