Eggtimer Quantum - No continuity but deployment test fires.

[Nick Hutton]

Ive got a strange issue with my latest Eggtimer Quantum. It’s my 3rd and not seen this problem on the previous two. FWIW I’ve prob built around 10 kits with no major issues on initial startup.

It boots up ok and the WIFI Connects. But when I put a load on the deployment channels, I dont get the Teal ready, rather the Red Off on each channel. However, when in test mode, despite the red channel, I can still start a countdown and fire the channel. Same outcome with both xmas lights and proper matches. Ive actually done the ground testing for the rocket with at least 6 successful tests on each channel. I only picked it up when I was prepping for a launch on Saturday arvo.

I’ve read the troubleshooting guide and Ive been over each of the optoisolaters, surrounding resistors and the wifi leads and reflowed every single join. Ive inspected the whole thing with a 10X magnifier loop.

Ive also successfully updated the firmware to 1.08Q. FWIW its Rev A18 board that I purchased 12 months ago in the Black Friday sales.

Anyone managed to troubleshoot the same problem. Clearly the circuits are complete or it wouldn’t fire the channels!

Nick

 

[cerving]

99% of the time it's a solder joint on the drivers, the other 1% of the time it's either loose terminal blocks or the processor's solder joints. Check them carefully with a 10x jeweler's loupe, the solder should go UNDERNEATH the drivers and join the elbow of the "J" leads to the pad. I recommend soldering these from the side of the leads... hold your iron to the side of the lead for a few seconds, then apply solder to the other side of the lead. This is why it's important to have the right heat and tip... if the heat is too low or your tip is too small you won't get the solder to flow, and if your tip is too large it's going to cause solder bridges. 1/32" conical tip is ideal, and if you have a soldering station start with the temperature at 680F and go up or down from there.

And BTW, it WILL fire if there's no continuity indicated... that's a separate part of the chip. Conversely, you can also have continuity without it firing.