Warning about ESD (when hardware-modding)

#1

Be careful of Electrostatic discharge. I had my gotenna mesh opened near my desk, waiting for the MCXX connector to come in the mail, charging and acting as a relay. Apparently I must have shocked it once as now it will not turn on.

The charging circuit will start and red LEDs will go solid but the button will not function. The Lipo battery is fully charged. Ive tried disconnecting the lipo (in order to fully shutdown the ICs) and checked that no components are missing or have connections broken.

So learn from my mistakes and make sure you anticipate and prevent ESD.

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#2

I went back with a fresh set of eyes and found that I must have dislodged a transistor. A bit of solder and it came back to life.

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#3

Are you going to try the VRX/VTX switch ? From my reading the MMCX doesn’t go hot until switched.

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#4

Yes I am looking at the feasibility of adding the MCXX jack back in but I am finding a few issues. I have another post on the issue. Adding an external antenna jack

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#5

Thank goodness! I’ve done stuff like that before and managed to make remarkable recoveries from what I thought were DOA boards. I’ve about given up on that old freeband RCI 2950, though…

Still, tis the season for static, so the warning may still save others’ bacon.

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#6

Glad to hear that it was another issue, but you should definitely take care when hacking/modding as ESD will often not cause any immediately noticeable damage. And RF devices tend to be especially sensitive to ESD.

Quoting from Wikipedia (yeah I know it is not always the best reference…):

A person carrying a relatively small electric charge may not feel a discharge that is sufficient to damage sensitive electronic components. Some devices may be damaged by discharges as small as 30 V. These invisible forms of ESD can cause outright device failures, or less obvious forms of degradation that may affect the long term reliability and performance of electronic devices. The degradation in some devices may not become evident until well into their service life.

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