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jumper locations

Teacher

jumper locations

Does anyone know where the jumpers go inside the MC?

 

There are 2 - 6 pin headers on the PCB one on the front and one on the back of the board

A total of 5 jumpers, 3 jumpers with metal in them (real jumpers) and 2 just plastic "jumpers" (they look a little different and don't have metal in them )

I'm pretty sure there were 2 lose in the enclosure originally (probably the dummy jumpers)

 

Oops lol

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Message 1 of 19
Guru

Re: jumper locations

I'll be very surprised if anyone here has the answer to your question.  The rumor is that the MC has an anti-tamper switch and that if you open it up, it bricks.  Does yours still work after you've opened it up?

 

Having said that, as long as you've opened yours I'd be curious to see a photo or two of its' innards.  Smiley Happy

Message 2 of 19
Teacher

Re: jumper locations

Yeah the jumpers are the anti-tamper devices. I think my MC fell over about a week ago and I have been having more then normal problems since then and heard stuff rattling inside it. So I thought maybe a heat sink or something fell off and something is over heating and shutting down causing the problems. Well I guess the noise was the jumpers :'( so I guess my cat bricked it and I made it worst by destroying the sticker at the bottom to get to the screws :'(. I still have NOT received an email form At&t saying the tamper devices have been tripped so IDK. I found this site http://my.reddit.com/r/netsec/comments/d7450/i_just_recently_got_my_hands_on_a_attcisco_3g/ a little too late and it had the pictures of the real jumpers vs. the fake ones so I tried that after I originally turned it back on but I only get 4 blinking lights and a power light still after 16 hours so IDK. I don't know what to do:'( I hate At&t and Cisco grrrrrrr

 

I hope the guy from that site reverse engineers the device and shows them up lol

Message 3 of 19
Teacher

Re: jumper locations

but yes I took many pictures

BTW from reading the posts on many sites it looks like the MC talks to like 4 different servers and if I ping them all (in one of the pictures) 50% of the time I get request timed out or 50% I get destination net unreachable I'm guessing this is 50% bad??? maybe that's why I get problems 1/2 the time?
Message 4 of 19
Guru

Re: jumper locations

Thanks for the pix.

 

One thing I was hoping to see in the photos is the MC's antenna.  I haven't picked it out though.  Can you tell what might be the antenna when you're holding that PC board?

 

BTW, I blame everything on our cat too.  :-D

 

edit:  Looking at the photos again, could that be the antenna the arrow is pointing to in this one?

 

 

MC.jpg

Message 5 of 19
Guru

Re: jumper locations

I believe the thing the arrow is pointing to is the GPS antenna. The cellular antennas are circuit board traces leading away to the right from the big tin can up at the top.

Message 6 of 19
Guru

Re: jumper locations

Looks right to me nsayer.

 

The reason I'm intersted in the antenna, of course, is to try to figure out what the radiation pattern might be.  If those traces are indeed the antenna(s), it would seem the pattern is likely oval shapped with the strongest points being broadwise to the circuit board.

 

Do you agree?

Message 7 of 19
ACE - Master

Re: jumper locations

I've been wondering about this myself. I noticed that during all of my troubleshooting, the lock on response (GPS, 3G) seemed to be faster if the MicroCell was parallel to my window instead of perpendicular, with the "left" side (as  you are facing the lights) facing the window. This is purely subjective but it did seem to be better in that position. Of course, I could just be drawing at straws because who knows what AT&T voodoo goes on inside these things.

___________________________________________________________

MicroCell Technical Guide by Otto Pylot

"Quick Tips: My Microcell Doesn't Work"


I am not an AT&T employee. For additional help, please send a PM to ATTMobilityCare

*The views and opinions expressed on this forum are purely my own. Any product claim, statistic, quote, or other representation about a product or service should be verified with the manufacturer, provider, or party.
Message 8 of 19
Guru

Re: jumper locations

I suspect the pattern is omnidirectional. In general a dipole will radiate in a donut shaped pattern, but a quarter-wave antenna should approximate an isotropic pattern (a sphere). I suspect that these antennae have been engineered for a omnidirectional pattern. The only thing that might change that is near field metal objects, but the most likely impact of them would be to detune the whole thing. Besides, at 1800 MHz, "near field" is only going to be a few inches.

Message 9 of 19
ACE - Master

Re: jumper locations

Interesting. We have a metal roof on our house but have never noticed any further degradation of signal strength for our cell phones before and after installation of the roof (as some have suggested). The the roof has been in place for years. I'm beginning to think that there are too many variables in how the MCs are placed and used in users homes, and AT&T just didn't do an adequate enough of a job testing these before they placed them in the field, because they were under such pressure to provide decent cell phone coverage inside and outside the home. Hopefully they're getting the "stuff" together and these outages and problems will diminish.

___________________________________________________________

MicroCell Technical Guide by Otto Pylot

"Quick Tips: My Microcell Doesn't Work"


I am not an AT&T employee. For additional help, please send a PM to ATTMobilityCare

*The views and opinions expressed on this forum are purely my own. Any product claim, statistic, quote, or other representation about a product or service should be verified with the manufacturer, provider, or party.
Message 10 of 19
Teacher

Re: jumper locations

From what I can tell there are two antennas for the cellphone traffic, are they for Rx & Tx? or does it transmit on two frequencies? The one antenna is about 2x longer ? I traced the traces in blue. And in green I circled what looks like antenna connectors, I guess if you didn't care about looks you could drill holes in the cover and connect external antennas if you wished

antennas

Message 11 of 19
Guru

Re: jumper locations

Those things in the circles are little tiny trimmer capacitors. They're tuned probably during final assembly.

 

The two antennas are for the two bands that the device supports - 850 MHz and 1.8 GHz.

 

Message 12 of 19
Contributor

Re: jumper locations

Is the picture posted above a functioning (non-bricked) microcell?  If so, I see where 2 of the real jumpers go, ie on the 2 leftmost pin columns. Can someone post a picture of the other side so we can see the other real jumper location? I would be most appreciative

Message 13 of 19
Guru

Re: jumper locations

By definition any opened Microcell is non-functional. The chassis has a tamper switch tha will brick the unit if it is ever opened.
Message 14 of 19
Contributor

Re: jumper locations

Even if one replaces the jumpers (i.e. - the tamper switch) before powering the microcell back on?

Message 15 of 19
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