Re: #u3s #synth 27MHz Crystal on Si5351 module failure? U3S just showing boxes... #synth #u3s


Al Holt
 

I've given the board a close review and there's not much I can tell with the board out of circuit. My oscilloscope (Tek T922) does show high frequency signal on the crystal pins so I'll assume it's oscillating. 

There's no clock activity on any of those pins (CLK0-1-2) that I can see and the SDA and SCL pins are 'high' at ~3.3v. Although this might be what you supposed to get when no connected to a I2C bus.

I did pull one of the BS170's and it tests good on my low-cost (but very, very handy) Chinese "Component Tester."

I'll probably pull the other BS170 and test it, try a couple of fresh ones. I'd better not overlook the obvious issues of cold solder joints and do some continuity checks.

Otherwise, it looks like the board is FUBAR and time to order another as well as the OCXO version that I've been meaning to try.

Thanks for the help and suggestions!

--Al

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