Signal issues after changing motherboard - Galaxy Note 4 Q&A, Help & Troubleshooting

Hi to all,
after change motherboard of my n910f (so it became a n910T), carrier signal became very weak, in every places.
Tried with 3 different bl\cp (for 910T). Also the newest. Tried with 3 different ROMs (1 MM 2 Resurrection). Checked the 2 wires inside. Tried SIM with other cells.
I'm afraid have touched something that broke some antenna, or so. It is very strange.
WiFi goes very well, as the rest. Only no signal, just a little.
Any ideas ?

I am facing similar issue, in my case i replaced the broken display. I get the full coverage only when i am in an OPEN area but other than (at work, at home) my phone is struggling to connect to network and people get "phone is switched off" message when they try to reach me. To troubleshoot the issue, i even replaced the SIM thinking it may be due to bad SIM card but no luck. Now i am suspecting that the latest firmware update from Samsung may have caused it. I am going to try out some custom ROM (i am on stock ROM until now) to see if it was indeed the samsung push that caused it.
Will post an update soon.

Related

problems with sim dropping out

Hi Can anyone help
I have an xda exec & love it very much but last week I started getting error messages saying invalid sim installed. sometimes a soft reset will cure it, sometimes going into & back out of flight mode & sometimes the only thing to do is remove & re-install the sim.
YES I have tried the sim in another device which worked perfectly & yes I have tried another sim in the device which had the same problems.
I tried for a replacement from O2 but it was out of stock & discontinued so they sent me a trion instead. nice but screen res is a bit low for using remote desktop sensibly.
I have tried flashing the O2 rom as well as some wm6 roms but to no avail.
Finally I swapped the screen onto a spare I had with a crushed screen but that device had a lot of screen flicker & a grainy effect to the screen.
Please help if anyone knows how to cure this problem.
Bad news: from reading your post, I think this might be a hardware problem. Have you dropped your device recently? If yes, that might have damaged the motherboard's connections to the SIM-slot, or the slot itself. If not, then it might be due to aging. However, in this case, a simple soft-resetting should not cure the problem.
You could try a hard-reset as well, your device might have caught a permanent bug.
However, you might want to wait for someone more knowledgeable than me in this topic.
Good luck
Thanks for your reply
The phone has been dropped a few times, but no visible damage to sim module. Think it is down to hardware, & is probably ageing.
It doesn't have to be a visible crack or such in the module, it's enough if the springs and stuff loosened up a little bit, and there, you have lost connection to the SIM, since the whole thing requires the card's contacts to be pressed up against the contacts in the module. even if there's a tiny bit of gap there, the SIM will appear to have disappeared.
The problem is, the warranty will not cover such, because this classifies as physical damage, and as such, it is not subject to warranty.

[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..

[Q] I9505: No WCDMA/LTE after phone damage & repair

Hello,
I had my phone water damaged and repaired, but now my WCDMA/LTE doesn't work and I have some suspicions they had a faulty repair on my phone. Here's a timeline of the events to understand why"
1. Bought I9505 (I live in europe, hence the european version). All worked fine, had HSDPA (no 4g when I bought it 2 years ago, since my carrier didn't support it yet).
2. Did a small dent in the phone's screen (cracked glass in the upper corner, near proximity sensor, tiny piece of glass missing [1mm], but touch screen worked fine)
3. Dropped it in water while on vacation. Quickly took out battery, bought a bag of rice and held it in rice for ~20h, hoping the water would be absorbed.
4. Next day I fully charged then turned on my phone, it was connected to 3g, I was receiving facebook notifications, my mother called me at one point and ringtone was working. The only problem: touch screen didn't respond at all so I couldn't answer or unlock my screen.
5. Took it to a local service, they changed my screen (and did a full reset on my phone that I wasn't asked permission for - that I didn't understand why, but I thought who knows, maybe they needed it for the screen change). However, I wasn't upset since I was more interested in getting my touch screen to work, and it did.
6. HERE's THE PROBLEM: yes, they fixed my touch screen, but now i have to use it only in "GSM only" network mode, since the others don't work: whenever I choose any of the other options ("WCDMA/GSM, WCDMA only, WCDMA/GSM/LTE"), I lose signal completely, and I get "Not registered on network" message when trying to call. I should mention that APN setting are correct and I tried the SIM in another phone and it worked. I also tried another SIM in my phone and it didn't work.
7. Somehow I thought it might've been the water damage and I was ok (although upset) with it. But I searched the internet for answers since I thought maybe I'd fix my phone due to a software/bad config problem. I used ODIN to flash different versions of official firmwares with no success.
8. HERE's WHY I'm SUSPICIOUS: I found some piece of information that said the LTE/WCDMA(data) module is embedded in the display, not in the motherboard. Upon further research, i found the USSD code *#2663# that tells me the display is from a SGH-I337 (S4 model used in the US). Thus, if the data module truly is embedded in the display, that would render my data service useless, since the US frequency is not the same with EU frequency.
What do you guys think ?
Is it truly the display's fault or did I get erroneous information regarding the WCDMA/LTE ?
Am I entitled to negotiate with them because they put an incompatible component on my phone for a partial refund or is this my phone's fault ?
Is there any way to force the frequency somehow so my phone works (rooting & modifying some modem files maybe) ?
I'm sorry if I had some presumtious/loaded questions, but it's all information that I had from the internet.
Thank you for your patience to read all of this.
Do us a favor please? Enter download mode (Volume -, Home, Power) and read off the model number listed there. Reason being that I suspect your phone was totally replaced, with an AT&T model.
Did that just now, the product name says GT-I9505. The IMEI is also the same as before (checked with the product packaging it came with when I bought it). Could they have any way to overwrite this stuff ? Because your knack is not unfounded - under the battery, the IMEI/SN sticker seems to have been peeled and re-glued since it's wrinkly and misaligned.
Worst part is they're authorized Samsung service partners, that's the reason I went to them and not another service. (I can find them on the samsung website, when looking for service locations)
It sounds like they simply moved your motherboard into an AT&T midframe. I'd take it back to them posthaste and have them fix it properly. Because LTE isn't working, and it was before they did their work, they are responsible.

[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.

I9505 network issues – is my Qualcomm MDM9215M toast? (probably not)

Update: There are other people in https://forum.xda-developers.com/galaxy-s4/general/ref-galaxy-s4-i9505-modems-bootloaders-t3315987 with the same issue, so it seems to be a SW issue. Still not resolved though.
So i create this thread to gather information as any search on the internet about S4 hardware failures seems to point into software related solutions only.
I encountered a problem after flashing RR-N-v5.8.2-20170414-jfltexx-Official.zip on top of a previous version. I was not able to use mobile network. I couldn't make phone calls and mobile data didn't quite work even though I was able to get an IP address at times. Later I found out that mobile network works well if I force it to 2G only.
I went and flashed multiple modems&bootloaders. I also flashed stock rom with Odin and even re-partitioned my phone with a .pit file. Nothing changed. I can also see my IMEI and the phone asks for my SIM card's PIN code as it should. I also have a signal strength of around -90 to -75 dBm.
At this point I assume it's safe to say that my problem is a hardware problem. I've already opened my phone to reattach the coaxial cable and speaker module as they have antenna contacs but I couldn't find anything suspicious. Except for the ICs.
The Qualcomm MDM9215M in particular has something on top of the Qualcomm logo. I wonder if this is is a clue. The chip is a "GSM / W-CDMA / LTE Baseband Processor w/ Memory" so an issue with it would probably fit my symptoms. But if anyone knows if these images show that it's clearly defective or if there's nothing inordinary, let me know!
Images of my main board:
http://i.imgur.com/URLlQQr.jpg
http://i.imgur.com/3sng3Og.jpg
I bought my phone second hand and I knew that it had had it's screen changed in a workshop. It might be the reason why I see a missing shiny tape (thermal material/interference protection?) when comparing the next image to this: https://youtu.be/zm4f2XjQLAM?t=12m24s The tape is right on top of the MDM9215M.
Missing shiny tape where the MDM9215M faces:
http://i.imgur.com/Hu8uOtu.jpg
Any ideas?
Edit: The goop on top of the chip is probably some protective material and the chip doesn't look defective, so the reason for my problems might as well be somewhere else.
Edit2: I also notice travelling lines on the screen while 2G is in use. I suspect the missing tape causes interference to the screen circuity close to the MDM9215M. It was caused by my newly arrived battery door which is probably made of aluminum foil.
did you have that same problem with stock rom?
it could be a RR bug.
MigoMujahid said:
did you have that same problem with stock rom?
it could be a RR bug.
Click to expand...
Click to collapse
Yup. I flashed both KK and LP with Odin and even re-partitioned my phone with a pit file to make sure there can be nothing left from previous installations.
The same thing happened to me, the problem started after updating the baseband for by odin.
xXCharlyGhostXx said:
The same thing happened to me, the problem started after updating the baseband for by odin.
Click to expand...
Click to collapse
I wasn't able to fix it. This seems like a common failure mode on these devices. But tell me if you find a solution

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