Default [Q] new mother board/ logic board
Have an sgh I337 att galaxy 4,
My issue and question, i have had this phone for a while it has seen a LOT of abuse, have replaced busted screen 2 times!
with that in mind latest issue and yes did factory reset camera shows nothing on screen and says a error, also wifi will not turn on at all slide to turn never connects goes to off position, ni assume due to many drops the board had said enuff, !
now my question if i buy a new logic board / mother board will i have issues connecting to my provider? AT&T, imei # and so forth, or will popping in my sim negate that issue?
no reply? meh
you can try to buy a new camera (for i9505) on ebay to fix it,
for the wifi sadly it sounds like a motherboard issue.
basically, if you buy a new mb its like buying a new phone, so make sure the emei is not blacklisted, other than that you will be fine
Related
After my AT&T Samsung Galaxy S4 screen cracked I figured that buying a new screen on eBay was the best course of action to take to fix the phone. While browsing for the best screen I came across a cheap listing of a Samsung Galaxy S4 already assembled screen (apparently the unit was DOA but the screen worked). Naively I thought buying this listing would be most convienent: all I had to do was switch out the internals and I would have a working phone and screen without having to take out the hairdryer.
It turns out, however, that I mistakenly bought the SGH-I720 model. There are several differences between the I720 model and the I1337 model. The external loud speaker from AT&T, for example, does not fit the I720 model. The digitizer touch component (located to the left of the battery) is constructed differently. The back casing (the plastic mold covering the internals) will not fit on the I720 model because of this digitzer component. Oh, and apparently I do not get any GSM service from my AT&T carrier.
The rest of the phone works perfectly though. Wifi, bluetooth, the camera -- etc. Everything else that was transfered over with the main motherboard works.
I suspect it's an antenna issue. Obviously, right? I do get some service though! I just have limited GSM connectivity. Is this because of a carrier lock? The key difference between the I720 and the I1337 is the bottom part of the phones (underneath the loud speaker). It appears that the I720 model has two antennas whereas my I1337 phone only has one. I'm assuming the I720 is capable of GSM connectivity (it says so on the product page) and therefore believe that the GSM antenna (on the right of the battery) should work. I also believe that it is properly working. Why else would I have signal (albeit weaker than I'd typically expect -- but that could be because I haven't fully constructed the phone and the case isn't on etc, etc.
So my question is: does anyone know how the carrier lock works? Does Sprint have it hardwired in the phone or is it purely software? If it is a software thing than I shouldn't have an issue -- I do, after all, have an AT&T phone in a Sprint body. Does anyone here with better technical expertise know why the bottom half of an I720 phone is simply incompatible with a motherboard from I1337? For testing purposes I connected the antenna from the motherboard in the I720 to the bottom half of the broken I1337 phone. I still get service but again -- limited connectivity and emergency calls only.
Any help? I'm thinking I should just cut my losses and buy a new screen and just manually replace the screen on the I1337 but I'm sitting on a working front end to a I720 and I really really want to make this work.
EDIT: I realize that it's L720 and not I720. Oops.
But here's an update: I moved back the motherboard from the L720 to the I1337 (where it came from originally). I just plugged in the screen from the L720 so that I could see what was going on (the I1337 screen is flat out broken). TURNS OUT that I don't get service period from the I1337 model! Which hopefully means that a) I'm not connecting something right or b) it's a really simple software issue that you guys know how to fix?
I did try calling 911 and I did hear a voice on the other side very briefly. I immediately hung up. So I have a feeling that my phone is connected to a network but isn't being properly recognized. Is there an emergency number that I could call to test my phone (that's obviously not 911)? I just want to hear a reocrded message or something that gives me a set of instructions...
You cannot use the L720 for any network other than Sprint in the USA. You have to call Sprint to unlock it internationally and then enter a gsm sim while out of the country and only then can you use it. There are several threads that explain all of this already. Just a suggestion but don't call 911 and hang up.
Sent from my Sprint Galaxy S4 using Tapatalk 2
Dude, I'm confused... You have an L720 logic board inside of an I337 body or is it the other way around?
Sorry for the confusion. I have the logicboard of an I1337 (AT&T) inside of the body of L720 (Sprint). The only Sprint components of the phone are the body, the LCD / digitizer, and the small electronic board found towards the bottom of the device (one end of the antenna is connected here . . . the other end on the logic board). See my attachment to get an idea of what I'm talking about when I say "bottom of the device."
Regarding using the L720 in the US with other networks: I understand that the L720 is locked to the Sprint network. However, I have an AT&T (I1337) logic board. Where does the lock come into play? If the lock is software based... it shouldn't be an issue. If the lock is hardware based but isolated on the logic board... it shouldn't be an issue.
same issue
Any luck resolving this issue?
i think i shorted out my s4 trying to charge battery with stripped wires because charging port would not work,so i took all the parts from another activated s4 with a broken screen which is on my family plan and put them into my s4 which would not even turn on and after replacing innards the phone now turns on everything works but wont activate tried soft and hard reset tried both sim cards. My question is after you swap parts out is there something i have to do to get the phone to think all the parts now inside are the original parts. the only parts in my phone that are original are the circuit boards or what i call chips which would have to be heated and removed which i am not willing to do. please reply everything works except wont activate. is it possible i fried the circut boards out?
Hi, I'm curious exactly where you put the stripped wires?
I understand there are 2 leads above the battery that are to support a wireless charging module/case. Is That where you hooked it up?
What exactly happened? did it smoke or turn off suddenly? Any visible black spots?
Also, very important, the main board (directly above battery bay, rear camera attaches to it) stores the IMEI # which will persist with the physical chip. I assume that's why it won't activate, sprint sees it as a different phone instead of your phone.
This might be ok though, as long as your IMEI is clear for activation. In this case, you just need a IMEI change on your account, and you should be golden.
(If unsure, call sprint and ask for ESN/imei check)
If blacklisted/active, then there are ways of repairing your IMEI. Legality of it is in the grey, but my view is if you own both phones, you can swap the imei's. Just don't sell the unused one, or zero out the meid (Google play won't work with 0'd imei so you'll have to make a phony one instead)
I used CDMA Tool, it took a bit of fiddling but with the proper guide, you should be able to accomplish it. (There's some kind of efs backdoor, and you must always first zero out the imei, then write a new one, never write a current imei to a new valid imei. For some reason it won't work, otherwise. (That was my experience, YMMV)
Last, you can buy the USB board that plugs in for about $6 on eBay. (Bought this today) this one is relatively easy. Unfortunately I found out the home button replacement requires removing the digitizer, using a heat gun. The USB board is one of the first things you see after taking plastic back off (9 screws).
Also, let me know how it works out.
Mvmcad thanks for reply, i put the 2 stripped wires in ]between the battery terminal and the terminls on rear of phone under the case it sparked but no smoke and no black spots, phone just would not turn on anymore untill i swapped all the parts .to get a clearer picture if u pop off your back cover and with the battery in place slide wires in between phone terminals and battery terminals at top of battery. would sprint be able to switch IEMI # over phone ?
Oh I see.. Yes sprint should be able to swap a IMEI over the phonr as long as you can provide the correct account information (they probably will ask for old IMEI as well as new IMEI). Gl!
OK so here goes. I had a phone basicly get destroyed. The glass broke and then when I attempted to fix it the up glue got in every sensor and then when I tried to remove the glass again I tore the digitizer. So I bought a bad esn phone in perfect condition and swapped the main board. Here is the strange part. My background is now on both phones, my saved wifi ssid's are still on my old phone but not the new one, and the old phone with the bad esn has mobile data. So both phones have data but I can not have them both on at the same time or I get crazy data connection errors. From what I understand the main board has all of the memory on it so can someone please explain this to me.
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.
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