[Q] No 3G/4G Signal, Possible Hardware Issue - Nexus 4 Q&A, Help & Troubleshooting

Background:
I was running the most up to date Paranoid Android rom, working great for weeks.
I went to the east coast (where my phone worked fine), and when I landed in Chicago, I turned off airplane mode and didn't have any data. I thought that was odd, so I tried a factory reset. No change. No big deal, I take another plane to Seattle. Then I only get Edge. The next morning I got 3G/4G for a few hours, then it was intermittent that day, but for the last 3 I haven't gotten any 3G/4G. That's where I am now, although I put on the 4.3 factory image and locked the device. This is what I have tried:
I'm on Straight Talk T-Mobile
1. My wife's T-Mobile post-paid sim card.
2. Cycling airplane, turning phone on and off
3. Flashing CM 10.1 RC3
4. *#*#INFO#*#* and messing with the settings, doing anything and everything I can think of. WCDMA Only, preferred, turning radio on and off, and trying to get to the radio band menu. The radio menu popped up just fine on CM10.1, but crashes on stock 4.3. When I select WCDMA Only, I get zero service at all.
5. Cleaning my sim card with rubbing alcohol
What I haven't tried:
1. Flashing a radio.
2. Taking it apart and inspecting the antenna connections.
Does anyone know if there are multiple antennas for the GSM/WCDMA radios? I looked on Ifixit and I don't see much info on the antenna. parts4repair.com shows only 1 antenna. The thing is, I get great signal on Edge, so if it's only one antenna, then I wouldn't expect such a good Edge signal. Also, the Edge/WCDMA signal processor is on the same piece of silicon, so I wouldn't imagine that would be a problem.
My phone has slipped from my lap a bunch of times and has been dropped on carpet quite a bit, never with any visible damage. I'm starting to think that it was damaged when dropped. I know there aren't great crumple zones on this phone.
Does anyone have any other thoughts, or ideas? I would like to try a few more things before I crack it open.
Thanks,
Ders

Update: I have since opened the case and disassbled the phone. I cleaned the contacts for all of the connections that I could find. I also see that the antenna cable attaches to the board that holds the micro USB port. Another plastic piece snaps in above that. This plastic piece has pressure contacts for a fractal antennna that is basically printed on this plastic piece. If I had to guess, the antenna may have been damaged due to flexing when the phone has been dropped. I ordered a new one on eBay and will see if that does the fix.
Another interesting thing that may disprove my theory. When I disconnect the fractal antenna, I still get an Edge signal. If it doesn't fix the problem I'm going to have to hook it up to an oscilloscope and see what kind of signals are being broadcast. That way I can see if it might be the signal processor chip on the motherboard.

Another update. I ended up replacing the USB board, antenna board and antenna cable. Works like a charm. Seems a little slower than my wife's Galaxy S3. But hey, it works now.
Sent from my Nexus 4 using Tapatalk

Related

Magician Radio issue

Hi,
I recently had a Magician shipped which seemed fine the first day of use, but at the end of the day, the gsm radio icon showed me a no reception, or 'service unavailable' message...
Now, after upgrading the Rom's (several used) and Radio update to the latest one (1.13 as far as I can see), I don't have any reception or 'service' at all...
The gsm radio always shows the '!' marker...
Anyone any idea where to look?
Loose cable, loose or bad antenna, software/rom issue?
Any ideas are welcome!
This device will be my test-unit for xanadux, but I want to make sure it's functional before testing stuff and debugging things that will never work because of a hardware or firmware issue...
Thanks guys!
Great work, super forum!
this is clearly a hardare malfunction. your device may not be identifying the sim card.
thanks for the quick response, but I don't think it's the SIM-slot that is causing me troubles... The SIM card can be read without any problem, and the pin code is asked and aknowledged by the phone. Once in a while I get coverage, but it always looks like 1 bar maximum, while my Trinity is lying next to it, same operator, and all 5bars of coverage notification are there, so it's not that I'm in a dead zone or black spot where there's no cell coverage at all.
I checked the upper back part (after removing the plastic casing top) and checked where the antenna is connected. Once, while holding and pushing onto the metal part that looks like the antenna extension, I got (just for 5 seconds that is) a connection, and signal level of 1-2 bars, but that dropped and stopped after a few seconds already...
I think it's a connection issue of some kind, internal antenna or the connection to it, but I'm not that keen on taking the unit apart to find out it's not that easy to sort the issue out...
Any help, info, ... can help...
Thanks!
the metal plate just below the top-backside plastic panel acts like the antenna.On top side of it there are two legs which connect to the mainboard.try cleaning the two spots on mainboard and the contacts of antenna.
well, i can say this because i solved this problem once this way.
good luck.
Well, I tried what you mentioned: scratched and cleaned the squares on the pcb, straightened the connecting metal parts from the back plate, cleaned all contacts: no solution...
Any other ideas?
Possibly a sort of switch which makes the device choose between internal or external antenna? What external antenna might fit?
Thanks guys!
Well,
I got my hands on a 'broken' I-mate Jam (got stuck between the car door, screen is totally broken, pcb is fine) and replaced the antenna block: FULL RECEPTION...
at least, for half an hour.. after that: reception dropped, and again left me with the "!" mentioning "no service"
I tried switching the pcb's but for some odd reason, the screen didn't come up good... The backlight didn't turn on and the screen was all striped and smeared...
Is there a difference in pcb versions, connectors, screens?
I thought Magcian = Magician, but now I'm thinking there are different models around there...
Bon... so I'm looking for a pcb of a Qtek S100 now... to switch that one with mine, and see if that helps...
really strange the reception was 'perfect' for about an hour, I even succeeded in making calls with it! No jitter, no drops, perfect reception, and then: BONK, over with it... nothing left...
Any ideas on this one, or any ideas on how to get the I-mate's pcb working in my Qtek?
Thanks guys for the info and help!

I messed up my signal!

I have problems with my signal at work, it's at the minimum in 1X. I can barely make/receive calls, and they cut out often. While at work I came across this video metacafe.com 963126 boost your cellular signal
It claims that by doing this simple project you can increase your signal. So I decided to try it. Sure enough, it works!
The problem now is that once I took the cable out for comparison of with Vs. without, i have no signal!
So, before I would have ~ 1-2 bars at home, enough to be in EV and get on the net without any problem. Now, I can't get on at all, and I can only get a line on roaming, which was completely disabled before. Also my extended battery which would only be at 50% after fri,sat and sunday's use is now at 27% sunday morning! (last charged friday afternoon).
So now I have modified it so i can keep this antenna inside under the battery cover and i'm getting 2 bars again, sometimes full bars (at home). I would still like to put it as it was before.
But my main question is, WHY did this happen? It's not like something got jammed up in the antenna plug. So, what are your thoughts?)
This thread, over at pdaphonehome, includes several posts warning that the connection to the external antenna connector is somewhat fragile, and if it is damaged it disconnects the internal antenna also.
http://pdaphonehome.com/forums/ppc-6800-xv6800/91095-antenna-port-what-can-used.html
Thanks for the info. I think you're dead on, the connection was damaged. I tried playing with it for a bit, but I just can't do anything. What i've done since then is left the external antenna I made inside the case. It works i'd say as good as before, and sometimes better. Oh well, what a bummer.
At least everyone else can know for sure now!
bakntyme said:
This thread, over at pdaphonehome, includes several posts warning that the connection to the external antenna connector is somewhat fragile, and if it is damaged it disconnects the internal antenna also.
http://pdaphonehome.com/forums/ppc-6800-xv6800/91095-antenna-port-what-can-used.html
Click to expand...
Click to collapse

[Q] Water damage

A few months back my Legend went through a cycle in the washing machine. Afterwards I did all the recommended things (take everything apart, leave it in the sun for a day or two, keep it in a jar of water absorbent silica in the evening). Anyway, after three or four days of that, I put it back together again and my battery was dead. Tested it with someone else's battery, and everything worked perfectly, I even made a call with it.
I then waited about 3 months for a new battery (it got stuck at customs) which I finally go this week. Thing is, I now have 0 connectivity with the phone no matter what I do. I always have 0 bars, I can't connect to wireless networks (even though I pick them up perfectly), and I can't get the GPS to turn on at all. Everything else works fine (including the FM radio), but there's no connectivity.
I was hoping it might be a software issue of some strange sort, since the wireless picks up well but just says "connecting--disconnected" when I try to connect. A hard reset did nothing to the phone though.
Is there anything else for me to try? I'm running pretty thin on ideas at the moment. Would replacing the back cover fix any of the connectivity issues? Also, is it still possible for it to be a software problem, and should I maybe try to install a custom rom on it?
Any advice at the moment would be much appreciated. Thanks!
EDIT: I just realised that I had made things worse with my reset. Now I have no file browser with which to sideload apps and no internet connectivity. EDIT2: Managed to fix the file manager problem with ADB. Now just the actual problem again
The GSM antenna is in the bottom part that covers the battery compartment - I'd say you have some oxide on those two contacts.
Take a small screwdriver (or a needle) and gently scrub those pins on your phone.
As for the two on the cover, you'll notice those two parts come apart, so I'd take the inner part and gently brush the two contacts with a piece of cloth and a toothpaste - it's a good thing to gently brush something.
If that fails and you're sure you plugged all inside as it was...it could be another problem...
You may also try bending the two contact in the phone out - these act like a spring, but be gentle about it
P.S.: Is your Legend at least clean now?
EDIT: Now that I think about it, you can try the phone with piece of wire:
cut a wire of : speed of light/frequency in Hz and connect it to the two pins inside the phone
For USA:
299 792 458 m/s divided 1 900 000 000 Hz = 0,15778 m
Thanks Dr.Romca.
I'm trying the clearning out for now. when you say the battery cover comes apart, are you talking about the piece of plastic inside the rubber? There seems to be an additional piece of plastic inside the rubber which might come loose, but I'm not quite sure how to pry it out without breaking it. Any tips on how to do this?
I'll give the piece of wire a skip until the very end
It's not glued or anything, just push the rubber part in the middle and try to click it out...
Dr.Romca said:
It's not glued or anything, just push the rubber part in the middle and try to click it out...
Click to expand...
Click to collapse
Ahh ok, I wasn't sure what to expect on the other side. Didn't want to jam a screwdriver in between the plastic and rubber and hurt some electronic component. Managed to get it loose though, and gave it a thorough but gentle rub down.
EDIT: Nope, still no service on it. I still find it strange that it doesn't want to connect to the GPS or the wireless either. As far as I know, those shouldn't be affected by an antenna issue right?
That's strange... WiFi and GPS antenna is in the other rubber part....
It seems there might be something wrong with the PCB...
I'm at a loss here...
Damn I have connectivity issues here...
The strange thing is it worked once after the washing...
If you have the courage for it, you can also try this:
Take the phone apart, I mean really apart, if you can unmount the display/touchscreen. Then take the PCB - mainboard, try to put a sticker over a microphone and the repro, then take a toothbrust and a detergent and brush the PCB - make sure you clean all, there will probably be some metal plates that look they can be unmounted, so try to unmount them and clean beneath them.
After this take the PCB and put it in the hot-air oven (if you have one - NOT a Microwave! ) 40 - 50 °C for like an hour should do the trick...
You can also use alcohol to clean the PCB, but since it was water that caused this, I'm gonna presume you'll have more luck dissolving with water again...
Anyway, that's what I'd do, but I'm and engineer, so if you're not sure, just take the phone to service
Hello,
The WiFi and gsm signal are at seperate places on your phone, so you either got a major problem with the hardware, or the ROM just went nuts. I suggest you flash a new ROM before you take the phone apart, cause it might get damaged irriversably..
Goodluck, keep us updated!
Sent from my HTC Legend using XDA App
Thanks for the continuing advice. You're right about the engineer thing though; since I'm not an engineer I'll leave taking the phone apart until the very end.
I've never flashed a ROM before, but I'm sure I'll be able to figure that out. What initially made me think that the ROM might have gone crazy is the fact that the wireless actually picks up networks. The further I get from a network, the worse the signal, and the closer I get the better, so the wireless signal is working properly. It just seems to have a problem connecting, which seems like a software issue rather than a hardware issue.
If that fails, I'll send it to HTC and see if they can do a repair for me. I already sent it to them for a check-up and a new battery directly after I had it dried out. I included explicit instructions that it got water damaged, that I was not looking for a warranty repair, and I would just like them to make sure everything is working and bill me for the repairs and a battery. Two weeks later I get the phone back with a note saying that they noticed some water damage, and they don't do warranty repairs on water damaged phones Anyway, I'll try them again.
If HTC fail to do anything again, I'll try my luck with a full teardown. Still, ROM flash first.
EDIT: Ok, so I followed this (http://forum.xda-developers.com/showthread.php?t=894465) post up until the end of downgrading your rom, and the problems are exactly the same. From my understanding, this would have installed a clean rom onto the phone, so any software issues should have been cleared up. I'll still try and install a custom ROM, just because I've always wanted to and just maybe something will work, but the software problem seems an unlikely explanation now.
This is getting very strange now. Using my newfound "Wi-Fi" Hotspot powers, I can actually create a Wi-Fi hotspot that my computer successfully connects to. Once again, if the hardware was broken I don't see how this could work. I still can't connect from my phone to any Wi-Fi network though.
As I mention (for a completely unrelated reason) earlier, I sent the phone in to HTC. This might be a very dumb question, but is it at all possible that the ROM on my phone works at a different wavelength/frequency than what is used by carriers in South Africa (where I'm from)? I'm thinking maybe HTC did a stock reset or something which changed it, because I never tested my phone after getting it back from them. That would also explain why my phone doesn't have reception with the current ROM. Just note that I have no idea how these things work, it's a complete shot in the dark
EDIT: My GPS also works now, or at least the gps indicator flashes when it should. Since I don't have any kind of internet access, I have no way of knowing if the GPS works, but in the past it never flashed.
I'm currently thinking of using my computer's wireless to connect to my phone, and then bridging that connection with my UTP connection to connect to the internet. I have no idea if this will work or what exactly if it will get me closer to a real solution, but at least having internet access on my phone will make things a bit easier. Will let you know how it goes.
So have you succesfully flashed a different ROM?I'm not sure what type of rom should you have but WWE by it's definition should work...So if you have rooted, try any WWE ROM...
Dr.Romca said:
So have you succesfully flashed a different ROM?I'm not sure what type of rom should you have but WWE by it's definition should work...So if you have rooted, try any WWE ROM...
Click to expand...
Click to collapse
I first downgraded it to 1.31, and now it's on BlaYo's B0.2.
can you check what radio you are using?
You may want to update it!
It's in settings / about phone / software / baseband version
My is 47.51.32.17U7.13.35.05
Not sure if there's a special version for SA, but here is a radio update only:
http://forum.xda-developers.com/showthread.php?t=706435
Sorry for the late reply. Real life caught up for a day or two.
My baseband version was 47.26.35.04u_7.05.35.26L. I updated it with the radio update you posted, and it's still not working. As far as I know, South Africa can use any American phone except those on Sprint, if that helps at all.
Also, I was away from home for the last week, and now that I'm back home my phone connects perfectly to the wi-fi here. I am certain that I did not make any mistake in connecting to the other networks I tried, as I tested the settings on multiple computers and entered the passwords multiple times, but the wi-fi seems to have been a red herring. So the only problem left now is normal phone connectivity.
I'm sorry to hear that...I'm not sure what the L means at the end...but about the wifi thing, it has been mentioned here that different locations use different WiFi channels...so at this point it's almost sure you have a driver/settings mismatch somewhere...
but I don't know much about that...sorry..

[SOLVED] Extremely weak Wi-Fi signal

The Wi-Fi signal on my I9505 is terribly weak. Sitting at the same desk the router is on - full signal; Walk 3-4 meters away - signal drops to 1 line; Go to a different room - disconnects due to no signal. I can only see 3 networks at 1 signal line while on another phone I get 11 networks - all with signal at 2+ lines.
My router is perfectly fine (works as expected and has great coverage on other phones/laptops - it still gives off great signal if I go next door/above/below me).
Phone software side I'd say is fine too, but I'm not 100% sure:
Issue happens both on latest WizCyan (TW based) and on latest RR (CM14 based), both using different kernels.
Currently on XXUHPG1 bootloader and baseband. PDA version is XXUPPI1 (according to the "Phone INFO" app).
Hardware side, I've tried a few things - bent all of the golden springs I could find just a tiny bit upwards, tried to clean the gray contacts on the mid bezel as best as I could (dry microfiber) - they weren't dirty or anything, but they seem scratched/shiny where the spring would have come into contact, is that bad? (I can take pictures if necessary)
I even flipped the blue antenna wire around (though I think that one only affects cell signal).
I also have to note that there's something wrong with my Wi-Fi IC / mobo because sometimes it stops working altogether (won't turn back on), needing a reboot or physical intervention. I doubt that would affect signal strength, as long as it's actually turning on, I guess?
Edit:
SOLVED!
Well, this is probably a very unique/fringe case - I found out there was a crack in my motherboard, just below one of the antenna connectors. I also found out that pushing down on where the crack is relinks the motherboard connections and gives back the full Wi-Fi signal. So I "ghetto-rigged" a piece of plastic to push down on the crack when I put the mid-bezel back in, and it seems to be working for now. Hope it holds up and doesn't cause other issues.
Actually, it could affect signal strength. You might want to check your antenna wire running down the right side of the battery compartment and make sure it isn't broken or partly disconnected.
You should also note that some phones have better antennas, thus having better reception.
So comparing it to a different phone isn't really a good way to measure the effectiveness.
Took some pics, I've no idea if they're of any help. Maybe somebody can tell if there's something wrong.
Strephon Alkhalikoi said:
Actually, it could affect signal strength. You might want to check your antenna wire running down the right side of the battery compartment and make sure it isn't broken or partly disconnected.
Click to expand...
Click to collapse
That's the wire I had flipped around. I even disconnected it to see if there's a difference, and it only weakened the cell signal. Full cell signal when I put it back. No change regarding Wi-Fi. If I run the phone with the mid bezel off, I only get 2 lines even next to the router, and it doesn't even connect - so I suppose the mid bezel antennas connect?
Pwnycorn said:
You should also note that some phones have better antennas, thus having better reception.
So comparing it to a different phone isn't really a good way to measure the effectiveness.
Click to expand...
Click to collapse
True, still, from full signal to 1/0 lines as soon as I go from my desk (and router) to my bed 5m away isn't right. Wi-Fi reception used to be as good on my S4 as on the other phones. (I can't remember exactly when this started.)
I believe you have a radio chip issue. Something that software cannot fix.
Solved. Thank you for trying to help.
@cLick1338: Telling people you solved the issue without revealing the solution doesn't help anyone who may come across this thread in the future. So how did you solve it?
Strephon Alkhalikoi said:
@cLick1338: Telling people you solved the issue without revealing the solution doesn't help anyone who may come across this thread in the future. So how did you solve it?
Click to expand...
Click to collapse
I had edited the first post. Figured it would be most visible for such people.
cLick1338 said:
I had edited the first post. Figured it would be most visible for such people.
Click to expand...
Click to collapse
If you edited it yesterday I wouldn't have noticed it. The XDA app automatically drills down to the first unread post and I don't always think to scroll back up.
Sorry.

SM G950U Network/Antenna issues

Heya guys, to make a long story short, bought an S8 on ebay, Verizon G950U, and was told the camera didnt work and there was no IMEI etc...
Upon checking, the front camera has a torn connector. I fiddled around with the daughter board where the antenna connectors etc.. are, (breaking the speaker and its entire cover in the process) and sometimes I randomly get cellular back, but it doesnt stay for long. i'm not sure whats faulty, but I'm certain it has nothing to do with the mainboard. The latest time the connection popped back was when I tried moving the back cover back on, I guess something must have clicked. I already reinforced the wires and the surrounding connectors, but I cannot get cellular at will. Would replacing the board in it's entirety be a fool proof solution? Hoping for help on the matter.
EDIT: Not sure if it was coincedental, but Also during one of the times the cellular service returned, it was immediately when I plugged my headphones into the device.
Akumai said:
Heya guys, to make a long story short, bought an S8 on ebay, Verizon G950U, and was told the camera didnt work and there was no IMEI etc...
Upon checking, the front camera has a torn connector. I fiddled around with the daughter board where the antenna connectors etc.. are, (breaking the speaker and its entire cover in the process) and sometimes I randomly get cellular back, but it doesnt stay for long. i'm not sure whats faulty, but I'm certain it has nothing to do with the mainboard. The latest time the connection popped back was when I tried moving the back cover back on, I guess something must have clicked. I already reinforced the wires and the surrounding connectors, but I cannot get cellular at will. Would replacing the board in it's entirety be a fool proof solution? Hoping for help on the matter.
EDIT: Not sure if it was coincedental, but Also during one of the times the cellular service returned, it was immediately when I plugged my headphones into the device.
Click to expand...
Click to collapse
I had a note 5 that cellular issues because the quik plugs for the antennas wore out and it did a similar type thing Once I swapped mbs it worked like a dream

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