[Asus  Eee Pad Transformer Prime] Thenits:
ITS ALIVE!!!!!!

There is something intermittent with the u7905 test point. I now have a wire stub I made at 40mm long inside the test point (see photo) and am receiving 12/16 inside the house. When rechecking everything I inserted a wire in the test point and it bounced back to life...I will investigate further..... i will find the f8cker.

Back on the mod path again....phew!

I am going to use coax again and try and pick up the prime’s antenna...I want to fix this so you can close the lid and not have wires hanging outside etc.

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Well I fixed my GPS good and proper! Totally stuffed it....it seems!

My prime had passed the return window and given the RMA situation being a total hit and miss regardless, I thought I would join in on the modifying ‘fun’. When something does not work but there is an intermittent light of hope, I can certainly relate to people going nuts to identify the problem and make it work….

Okay first thing I tried was to use a small screw driver to see if contacting with the GPS pogopin would do anything.....major improvement - 15 satellites and 9 locks inside the house ...amazing! This was my baseline for performance. Same location, same contact procedure etc…..not laboratory standards but it works.

I then tried the shim idea using various thicknesses to no avail. No signal and it was becoming apparent that the pogo pins needed to be bypassed altogether. I was adamant I needed to go from a soldered connection on the antenna pcb to a soldered connection to the main pcb.

I had been looking closely at using the U9707 and U9705 connector (test points) as potential locations to directly connect the antenna pcb with rf coax. I tested both continuity (dc) and rf by using a small piece of wire and inserting it into the test points. They do not seem to be connected (independently verified by others) and therefore cannot be used (most likely the in-line capacitor is at play here). The connectors are not u.fl (also independently verified by others) and while you can modify a female u.fl connector by placing a pin inside and that it does securely fit, it is irrelevant given the previous point that they do not seem to be able to pass a signal. Regardless and to test this I proceeded to modify a u.fl connector attached to a rf coax and soldered directly to the antenna pcb…..tested for continuity….all good…but no signal …previous reason why.

Tested the pogopin again with a screwdriver….all good ……signal booming in.

I am going to find the little f8cker...

I then cut-off the u.fl connector from my previous mod and soldered the signal conductor to the pogopin base and the shield to the adjacent ground point. The other end was still soldered to the antenna pcb signal pad (where the pogopin usually contacts) and to the antenna pcb ground tab. All checked for continuity….all good…this is going to work….has to!!!!…friggin pogopins… I have lost way too much time thinking about this ….reading blogs, mentally abusing ASUS. NONE of us should need to do this…poor design, QA….this new mod was going to prove once for all that the signal path was an engineering cluster f*ck!.....ASUS knows this and doesn’t give a sh*t…arrogant bastards…’we will just remove the GPS from the specs’…..unbelievable!!!!.

Turned the prime back on and NADA…..nothing inside the house….pogopins bypassed using rf coax (50ohms...the correct stuff) and continuity all checked. It’s not the antenna pcb design given the intermittent squeeze technique…what the hell is going on???

Placed a screwdriver on the GPS pogopin to get a signal confirmation again...and NADA…WTF!!!

Removed the coax from the pogopin and the antenna pcb…retest using the screwdriver…..NADA….SH*T!!!....SH*T!!!!....Nooooo come back! retested contunity on friggin everything...all good...F*CK!...still no signal!

DEAD GPS!!!!...... I am sooo pissed!

I do not know what I did…powered off during soldering…very careful soldering technique....I have done far more delicate work…. but now I have ‘fixed’ my prime’s GPS good and proper it seems. It was a usuless piece of SH*T anyhow...sorry... no amount of justifying why I don't need a GPS is going to help. I would have probabaly never used it anyhow, but that is NOT the point!

Be careful when playing around with mods…there are some real sensitive connectivity issues at play here that are not that obvious. This is perhaps why people are having varying results.

Apologies for the long story line but the moral of the story is that we shouldn’t have to be even considering doing crazy arse sh*t like this if ASUS told us what the frig was going on in the first place. Hey even better - providing a mod of their own…go figure…. Maybe they don’t know the exact cause themselves, but I seriously doubt it… the back aluminum case certainly attenuates wifi and gps signals, but the intermittent improvements some people see may be caused by varying reasons. Good luck to those who snagged on to a solution. For those who have not tried yet but are still considering….be careful!!!