Bummer.
Is the Bluetooth antenna intact? I think there’s a SMD right where it exits from under the RF shield that might be involved.
I only know about such things because I trashed mine, of course. Mine pairs fine, it’s just an energy hog once lit. And it tends to quit when nudged the right way in the right spot - ironically right next to that Bluetooth antenna.
Probably a good time to mention the excess energy use seemed tied to my connecting both the red and yellow leads to the outer posts of the switch. So I tried disconnecting them one at a time. Both those alternatives failed. I haven’t swapped the red and yellow leads on the switch yet, which is the next experiment.
Yay!: This project. Boo!: Mesh won’t pair. Oh no! 
I think Mike has some ideas on next steps. Let us know the diagnosis!
Set aside for the moment. The PU Truck also died & I need it more.
I did some more experimentation. I swapped the leads on the switch. That helped some but then it became clear the original battery was shot. I replaced it with 500 mAh 1S 3.7 V Eflite battery from Horizon Hobby. I had a spare JST connector, so now it’s even plug n play.
It seems to relay and works fine when paired. I’m planning on using it to replace the intact GTM that’s in the home node, freeing it up for use on the street. Once crashTenna is boxed securely it’ll be OK despite the loss of its RF shield.
I find shorting the center switch pad to the one nearer the USB port to be the ticket. Is that what you are using ?
I have also added connectors so I can switch out batteries. Now to put the SMA back on. While I was playing I just put a whip antenna on it so that the xmitter would have something to load.
I am assuming that the squiggle under the white ink on the side opposite the switch, just down from (what looks like it is) C16 is the BT antenna? It seems intact.
Yes, looks like C16 leads to the BT antenna, the squiggly thing.
I’ve tried different hookups to my Power switch. Currently, its back to non-functional just when it seemed to have settled down to turning on and off reliably.
Mike, do you know what the different pins on the power switch connect to? Does it power the Mesh on by driving the signal lead low?
I ask because I’m looking into ways to have the Mesh auto-power on when driven by an external circuit, and figuring out how the power button circuit works would make this a lot simpler.
Not really. The middle one is the ground IIRC (I’ve got it put away so going by memory.) If not, it’s the +. 
The outer two are the opposite of whatever the center is. I’ve swapped them back and forth and left one or the other off with varying results, mostly not allowing battery charging.
Sorry if this sounds lackadaisical, but I think encouraging experimentation by noting it won’t hurt to try swapping things around is useful. I just have to plead a certain level of ignorance to the rest at this point, as I got so far and the need to make measurements at the SMD level without the proper equipment stymied progress here along with other recent distractions.
Before I crack one of my units open, does anyone have the dimensions of the bare circuit board?
It is 15/16" wide by 3 13/16" long. Note it is irregular in shape. Board plus SMDs on one side is about 1/16" thick (without the RF shield), while the USB micro socket on the other side is about 1/8" tall. The battery is also on this side and slightly thicker IIRC although mine is disposed of.
Awesome. Thanks. I tried to guess from the pictures above, but what I’m trying to fit it into is too close to tell.
Finally got mine cracked open. It certainly isn’t easy to get one of these open. The only things that survived were the board/battery and the aluminum vanities. The plastic housing has no hope of going back together and looking half decent.
Kudos to the engineering team for following the proper full charge voltage of 4.20 volts. Unlike cell phones, keeping a goTenna at full charge isn’t nearly as harmful (official Motorola documentation pushes the batteries to 4.35 volts).
I have already modified 2 gotenna mesh units to have external SMA antenna connectors and I would like to modify more.
I read somewhere on here that the newer hardware revisions are harder to mod due to the RF shield. Is this true? Is there a way to tell which GoTenna’s are the older (easier to mod) hardware revisions without cracking them open? Such as the serial numbers?
Thanks & 73!
Jim - KH2SR
Jim,
Having taken one apart unintentionally (hard to do, although the Landcruiser did most of the heavy lifting) the shield itself isn’t too big a deal. There are some things scattered about near it on the periphery of the circuit board that you have to be careful to preserve or modify as the case may be. But if you can handle putting SMAs on, I’d bet you have the chops to deal with the RF shield.
Just happened to think of a mod that I’d like to see that I’ve been thinking about. Something to chill those blinding LEDs! They light up things to catch your attention, but after they get you trained to pay attention to them, then OUCH! they are like a sharp stick in the eye. A resistor in just the right place may do it, but likely would need more than one and they’ll be tiny, wherever they need to go.
If I can help it I would rather avoid the models with the RF shield. Can anyone shine some light on which serial numbers represent the older units which don’t have the shielding and are easier to modify?
Most Mesh with serial numbers bellow MX17270000 would be the units without the RF shield.
I was also just informed by MrTSolar that another way to tell the difference is by looking at the LED’s while charging. If you see a honeycomb pattern (line of well defined dots of light) in the LED’s then it has the RF shield. If the LED’s have smooth/even lighting then there is no RF shield and will be easier to mod.
Here is an example photo.
The gotenna on the left has smooth light & the one on the right has very defined dots. Which are the holes in the RF shield.
Well that is interesting. My AA12341234 device has the right side honeycomb. My MX 173 has the smooth two lights. I thought the AA versions were older.
