sparkfun thing plus - samd51 wouldn't work unless the oscillator circuit is touched.

Kits
1

Earlier the code would upload automatically in the board “Sparkfun thing plus- SAMD51” in bootloader mode and last program would reload after powering up. However, I am encountering this particular issue now.

Any code would not upload unless i touch the oscillator or the oscillator capacitor using my finger/wire/any conducting material. Same behavior is observed in reloading of a program after powering up i.e. last program won’t load after powering up until i touch the oscillator/oscialltor cap/Xin or Xout pin using a conductive material.

I am unable to understand what might be causing this. Any help would be highly appreciated. Thanks.

2

Hello priyanshi.

That’s a new one on me!

My guess is there’s something wrong with the load capacitors on the crystal or the crystal itself.

Can I get your SparkFun order number?

3

Hello Chris.

Apologies for the very late reply.

I had ordered it from mouser.

Details are:

Mouser no: 474-DEV-14713

Mfr no.: DEV-14713

Invoice no: 54152463

I had ordered this 3 Oct '19.

There were two boards out of which, one works completely fine but the other one doesn’t. It started showing that behavior after I tried to probe it around oscillator capacitors. I think capacitor value might be fine. Having a closer look shows the same capacitors have been soldered to both the dev boards.

4

Hello priyanshi.

It sounds like a bad crystal. You will need to contact Mouser for a replacement. They should be happy to help you out with that. :slight_smile:

Happy New Year!

5

Thank you, Chris.

I was just curious about what could have happened to it after I probed it that might’ve messed it up since it was working fine earlier.

Happy new year to too! :slight_smile:

6

It’s hard to say.

If you accidentally shorted the crystal leads, there’s a possibility something in the SAMD got damaged and the SAMD lost the ability to get the crystal oscillating. By touching the crystal you could be introducing just enough energy to get the crystal oscillating and once it starts the SAMD might be able to keep it going.

It’s more likely that either the crystal or one of the caps was on the verge of failing (defective) and your probing was enough to push them over the edge. Defective parts are not very common, but do happen from time to time.

7

I see.

Thank you very much for your help.

Best,

Priyanshi.