Database Users

S100 Loses Signal

Hi, I hope someone can help me.
I dropped my phone a couple of months ago and now I'm experiencing a problem. It appears to work fine for hours then suddenly starts losing signal strength to the point where it goes altogether. I can start a call with 5 bars and be cut off with no signal in a minute even though I've not moved. It will nearly always lose the signal when I'm on the phone but takes longer when just in other use. All remaining elements of the phone work fine. Please can someone suggest what it could be as it is getting me down...thanks

I'm sure it's a hardware problem.

have got the same problem.Did you already find the problem.In the beginning the signal just dropped but know i even cannot find any service at all.
gr

I've had some luck by raising all the contacts under the sim card but the signal still comes and goes when I use the phone ??

Snap!
I droppped my phone the other day and it is doing exactly the same thing. Mine is a Qtek S110. I used to 'lurk' on this forum ages ago.. but [email protected] BACK to seek help! If and when I get my phone fixed I WILL post and let you know what it is, if I havent already found the solution here!

I think it definately has something to do with the SIM holder, whenever the signal decays and vanishes, if I take out the sim and put it back in it comes back straight away. if I just take out the battery and replace it doesn't

ok.. next time i lose signal I will do that. maybe even run some isopropyl alcohol over the contacts to make sure they are clean.
I will keep you posted in my findings!
(oh.. i tried a makeshift external aerial last night to see if I could see if it was an internal aerial fault. It didnt make any difference, so either my homemade job was [email protected] or it isnt an aerial problem, I'm yet to find out!!)
Cheers!

oh poooop..
that unfortunately didnt work for me.. Oh well. i even tried cleaning the contacts and making sure the 'sprung' contacts were connecting with the Sim correctly.
I actually lost signal until it came back 15 mins later.. hmmmmmmm!!!

Can anyone advise where I can look on the circuit board to see if there is any damage. I am capable of doing this and making a basic repair !!

I had a look at the mda strip down guide on here, but I could see any reference to the aerial or anything. I think I'll have to send off for repair! Doh!

I emailed HPC and they wouldn't take mine back as apparently it was not sold in the UK.

I think I'll give xdarepairs.co.uk a go. a mate of mine said they were good n' quick.

merceeeeeeeeeeeeeeeeeeeeeeeee

no wurries!

the unit that sorunded in red (in the Attached picture) is connected to the main board with tiny connector, and this connector is a male to female connector. the male is solderd to the main board and the female to the unit. my guess is that one of the connector parts (the male or the female) was disconnect from its soldering, and you need to resold it. but it is just my guess based on my experience.

I was taking a look at the mda-jam.pdf guide to removing the case and it suggests that the aerial contact on the board you have pictured is with the front panel.
Can anyone confirm if indeed, the aerial for the phone is the metal casing? That would suggest that the dents in the front of mine could have affected that very contact.

Would still like an answer to my previous post.. but I think I may have fixed my phone temporarily.
Using the above information I got a flat bladed blunt instrument (in this case a normal dinner knife) and carefully placed it into the empty sd card slot. Using the diagram from the case removal guide I applied pressure with the knife to the area where the 'aerial connector' rests against the front bezel, inside, whilst at the same time pushing on the front outer casing with my thumb in the same position.
The thought process being, that it may have worked loose.
Sure enough I have noticed a vast improvement in signal yesterday and today. I am going to keep an eye on the phone today when I go out to see if the signal stays up!
YAY!

Okay.. latest update.
The signal did drop out a little bit throughout the day, So I have taken it upon my self to put my electronic training to good use.
Using the (now much read) case removal manual I carefully .. and I MEAN carefully took my phone to pieces.
I was convinced that the reason my signal kept dropping out was either that something had worked loose or that there were some contacts that needed cleaning or reseating.. as I was able to get a signal by squeezing the case at the top.
So.. Here's what I did (In reverse order)
Page 9 straightened and cleaned the 3 contacts on the RHS plastic plate with isopropyl alcohol. Also cleaned the corresponding contact points on the main PCB with alcohol and dried with a lintless bud.
Page 10 3 contact points, top right and top edge left are the contact points I refer to above. Also cleaned the 2 sprung contacts at the bottom of the PCB RHS page 10
Page 16 cleaned sprung 'Aerial Output' contact with alcohol.. also pushed connector outwards to make a betterr contact. Also cleaned 'contact to the antenna' area and dried thorughly with a lintless bud. Any other contacts I could see were cleaned and dried too.
Whilst putting the phone back together I was very careful not to touch any components. Battery contacts and Sim contacts were also cleaned.
One thing to note in the manula is that it it possible to unclip the connector for the camera prior to removing the plate in page 8. However, it is probably best to follow the guide, if you are unfamiliar with the type of connectors used. They can break easily.
My phone booted correctly and is currently on charge.. I am checking functionality at this very moment and can see that the signal is good and all other parts / hardware functions appear to be good. watch this space! It COULD be one fixed phone!!
I can't remember who on this forum wrote the mda-jam.pdf manual, but I would like to publicly thank you as you have helped fix my phone!

I hope its worked !!! Let me know !

OK!
Well so far I have noticed a dramatic improvement on how the phone was. I am sitting here with full signal, whereas on Saturday I had between 2-3 bars.
I lost a little signal earlier today but as soon as I held the phone up, the siganl came back. So, it's not perfect, but the phone is useable now.
As long as it lasts for the rest of my contract, I'll be happy!!
Dood.

[REF] GT-I9300 Service Manual

Here is the Samsung Galaxy S3 (GT-I9300) Service Manual.
Please take a moment to read the notes and issues about this manual in this post.
For some reason Google didn't pick up that post, so I had to re-post here...
Now, if you are brave and happen to have a GT-I9300, you can still help us by posting some
internal pictures, to verify some issues in the manual. If they are good,
some of them will eventually become part of the SGS3 Hack-Pack.
Thanks and Enjoy!

I will be opening up the phone in the next few days due to me managing to damage the sim card holder section(not holding sim card) So at present i have got somthing putting pressure to keep sim card in place. I have a new sim card holder on order so when it arrives i will pull phone apart and take some pictures.
If you have any advice for me before attempting this please let me know via pm

Do you have any experience in this kind of electronics? I mean, are you planning to replace and solder the SIM card holder by yourself?
If you have not done this type of soldering before, I do not recommend it.
If you do decide to do it on your own, make sure:
You are working on a clean workspace
You are well grounded and not wearing wool clothes mixed with synthetic materials to avoid any ESD.
Have the right tools for the job.(Temp controlled SMD soldering iron + flux and acid-free lead-free SMD solder etc.)
A very steady hand with good eyes!
As for the pictures, keep the environment as bright as possible, preferably daylight. Try to keep your PCB on a bright or neutral background. (Bright cardboard is usually good.) Inspect your pictures and make sure you can read the text on the smallest chips. (The big ones we already know about, its the smaller ones that are difficult to navigate around.) Make sure the pictures are well focused.
Good Luck!

From looking at the pictures I was hoping I don't have to solder the sim card slot in. It looks easily replaceable as it looks like it's just a connector and not soldered

Replaced the sim holder. My camera wasn't good enough to get focus of the smaller chips however it is very very easy to take phone apart. And I guess Samsung are expecting issues with sim slot so they have fixed it using one screw and connected to board using a pull off connecter.
Just in case anyone else is interested the sim holder/sd holder cost me £20, delivered.

E:V:A said:
Here is the Samsung Galaxy S3 (GT-I9300) Service Manual.
Please take a moment to read the notes and issues about this manual in this post.
For some reason Google didn't pick up that post, so I had to re-post here...
Now, if you are brave and happen to have a GT-I9300, you can still help us by posting some
internal pictures, to verify some issues in the manual. If they are good,
some of them will eventually become part of the SGS3 Hack-Pack.
Thanks and Enjoy!
Click to expand...
Click to collapse
amazing !!!

Hi guys,
Here is my contribution to da community, hope so it helps.
h t t p s : / / docs . google . com/open?id=0B9lrf7AWQW7ETjRZTkFXb1luN0E
On image 20120616_150200.jpg you can see the region jumpers. The images are of a live demo unit - everything works besides the GSM/3G data. Haven't tested to see if the NFC is working.
The real unit has some more antenna connector. The demo one does not have PBA /printed board antenna/ the ANT102 and ANT103 as well as the capacitors and the coils u may seen them market in red cycles (ANT102, ANT103, C102, C191, L103, L102) there is no room on the MOBO for C192 /or at least I can't find its place/.
Thanks.

^^ Here is the link for above! (Thanks!)

Hi again,
I can confirm that the NFC is working on the live demo unites. According to the original S3 user manual the NFC antennas are build into the battery back.
I still can't figure out what is the "W2" antenna connector for. The Live demo unit has no connector soldered to the motherboard and also lacks the small PCB antenna with the white coaxial cable. Some ppl claim that the W2 is for WiFi antenna, but it is not, because I got great WiFi connectivity tho the lack of such PCB antenna. I can only confirm the WiFi working fine, under "G" type of WiFi networks. The openWRT firmware of my current router has known bug and I can't bring up "N" standard in air, to check if the PCB antenna is for "N" type of WiFi networks.
I also did some testing to see if the PCB is for GLONASS or GPS, and it seams that this PCB antenna with the white coaxial cable is not for any of these services. That's why I think it might be for wifi "N" or 3G data/networks. Donno if the 802.11n requires a separate antenna.

^^ Please post a link to a specific image, that clearly show the connector(s) you're talking about.

Hi I have a live demo unit to, so I think I can help about this =).
I can't show you the mainboard back because I' m new user... xD
I don't really know what you mean with NFC (sorry, I'm not really good with english)
But
W1 is a GSM external antenna conection
W2 is a wifi external antenna conection
And the white wired antenna is for wifi to.
After thinking a lot, if you conect an antenna to the GSM antenna conection (external or the internal lacked in Demo unit) you probably can't use phone function.
That function probably was crippled by software or because demo units don´t have imei maybe o.o.
The only thing I need to try is to connect a microsim to the phone

No one has any insights ???

johnny21a said:
No one has any insights ???
Click to expand...
Click to collapse
I have sgs3, international version on my workbench right now.
Don´t have any clue what could I share, so - if there is anything specific -- let me know. I will do my best..
BR

Samsung galaxy S3 i747
i have a Galaxy S3 SGH-i747m that has been water damaged and given to me so i could try and fix it. I can take pretty much any pictures you want, have openned the phone a couple times now to try and clean it up.
My problem is that the works well, it starts up, unlock the screen, plays sound...but the screen is off. Now at first when i was "playing" with it the screen would flicker on and off to show me the battery charging logo when it was plugged in. I've cleaned the phone and all flex connectors with some products. the phone still turns on and works but my screen is off. It detects the touch since i can unlock the screen ( it plays the water sound when i slide my finger on the screen) and speaker works when i boot it up (little booting sounds).
I was thinking there might be a small fuse on board for the screen backlight and that could be blown. I was also thinking my battery might be damaged and is not giving the phone the right voltage to the right connectors or something so i have ordered a new battery on ebay (under 4$) and am waiting for it.
Anyone has an idea to some specific things i should be looking for ? only thing haven't disassemble is the digitizer from the framebecause doing so would surely break the glass. It bums me up a bit since there are some electronics behind the frame that could have been damaged by the water that i couldn't see.

Bigred065 said:
i have a Galaxy S3 SGH-i747m that has been water damaged and given to me so i could try and fix it. I can take pretty much any pictures you want, have openned the phone a couple times now to try and clean it up.
My problem is that the works well, it starts up, unlock the screen, plays sound...but the screen is off. Now at first when i was "playing" with it the screen would flicker on and off to show me the battery charging logo when it was plugged in. I've cleaned the phone and all flex connectors with some products. the phone still turns on and works but my screen is off. It detects the touch since i can unlock the screen ( it plays the water sound when i slide my finger on the screen) and speaker works when i boot it up (little booting sounds).
I was thinking there might be a small fuse on board for the screen backlight and that could be blown. I was also thinking my battery might be damaged and is not giving the phone the right voltage to the right connectors or something so i have ordered a new battery on ebay (under 4$) and am waiting for it.
Anyone has an idea to some specific things i should be looking for ? only thing haven't disassemble is the digitizer from the framebecause doing so would surely break the glass. It bums me up a bit since there are some electronics behind the frame that could have been damaged by the water that i couldn't see.
Click to expand...
Click to collapse
check if you can see anything on the screen, use some extra light, torch for example.
if so - then its more likely that the LEDs in the display panel are damaged, since it flickered, as you said. also could be the driver circuit for backlight. Clean connectors for display panel, use magnifier, or better microscope to check for corrosion. use IPA to clean or scrape off the corrosion.
also - maybe this is not the right place to discuss this.
GL

Redrigon said:
Hi I have a live demo unit to, so I think I can help about this =).
I can't show you the mainboard back because I' m new user... xD
I don't really know what you mean with NFC (sorry, I'm not really good with english)
But
W1 is a GSM external antenna conection
W2 is a wifi external antenna conection
And the white wired antenna is for wifi to.
After thinking a lot, if you conect an antenna to the GSM antenna conection (external or the internal lacked in Demo unit) you probably can't use phone function.
That function probably was crippled by software or because demo units don´t have imei maybe o.o.
The only thing I need to try is to connect a microsim to the phone
Click to expand...
Click to collapse
I don't have he white antenna coaxial cable neigh the PCB antenna board that this cable is connected to but I have WiFi.
Could it be for WiFi N(150Mbps)?

Watter damage, LCD working/not working?
Bigred065 said:
i have a Galaxy S3 SGH-i747m that has been water damaged and given to me so i could try and fix it. I can take pretty much any pictures you want, have openned the phone a couple times now to try and clean it up.
My problem is that the works well, it starts up, unlock the screen, plays sound...but the screen is off. Now at first when i was "playing" with it the screen would flicker on and off to show me the battery charging logo when it was plugged in. I've cleaned the phone and all flex connectors with some products. the phone still turns on and works but my screen is off. It detects the touch since i can unlock the screen ( it plays the water sound when i slide my finger on the screen) and speaker works when i boot it up (little booting sounds).
I was thinking there might be a small fuse on board for the screen backlight and that could be blown. I was also thinking my battery might be damaged and is not giving the phone the right voltage to the right connectors or something so i have ordered a new battery on ebay (under 4$) and am waiting for it.
Anyone has an idea to some specific things i should be looking for ? only thing haven't disassemble is the digitizer from the framebecause doing so would surely break the glass. It bums me up a bit since there are some electronics behind the frame that could have been damaged by the water that i couldn't see.
Click to expand...
Click to collapse
I have identical symptoms with my i9300.
1. Water damaged
2. Dried in a can of rice etc over several days
3. Cleaned under sim card, lots of debris there, looked scorched, I cleaned with alcohol and a brush in an ESD protected environment.
4. Re assembled, the display briefly flashed on, and showed the expected "Battery is low, an d No Sim Card" then powered off.
5. Now after charging the battery and emplacing my sim card, I hear the proper musical tones when the phone boots but the screen doesn't light.
Where you able to get the screen working?
I am going to try a more throughal cleaning and I will try viewing the LCD under a more power full light.
I too worry that just getting the LCD screen replaced might not work; the screen may be fine but the mother board LCD power supply might be at fault...
I will keep you posted and keep an eye on this forum to find out how to fix this.

This thread has served its main purpose.
OT discussions are prevalent.
Thread Closed!

[Q] Mytouch 4g wifi not functional after LCD replacement

I just recently replaced a malfunctioning LCD and shattered digitizer for my Glacier. Before I did that, the WIFI worked just fine. No problems at all. But now, the WIFI will turn on, but won't pick up any networks at all. All my other phones pick it up just fine, as well as my laptop. I've tried three different ROMs and I have the same issue with all of them. As far as I know, there weren't any cables that connected the WIFI module to the motherboard or anything else when I took it apart and put it back together. It's just a little piece that snaps into place, right? I'm not sure what's going on with this...

Seriously? Nothing? Every time I post on here, I get ZERO response... What gives? I see everyone else's problems being solved but not mine...

Sorry, there's no help to give. Don't act like you're entitled to something. I hate people like that. If you didn't touch the WiFi module through the screen and tried different roms then it went bonkers and its toast. TF are we supposed to do about that
Sent from my HTC Glacier using xda app-developers app

If you're gonna post on here just to be a douche, you might as well not post at all. It's doing nobody any good.

All drama aside, he is right nothing to be done really. I guess you could open it back up again and risk breaking something more important than the wifi. Something may be put back in wrong or may have got ESD damange. Truth is unless you're just using this phone as a toy/dev/learning device and don't care if it breaks it is not worth the risk to open it back up.

Trying to fix my external speaker - I mess up working wi-fi. In addition, the case crack and camera button is not working. Should take it to repair shop. Too late now. It would be too expensive to fix it. You my still be lucky and shop will fix for few bucks. Lesson learn - do not mess with something that you do not understand( for me).

coax cable issue
there's 3 little coax cables - I've been told the white coax is the wifi but the black one fixed it so maybe they are all involved. In the process of getting to the LCD you went through these 3 cables. In most cases you wouldn't have disconnected them but certainly by accident it will happen. I put mine on 3 times before they stayed. There's quite positive click when connected but even then it may come loose while assembling the rest of the phone. I just finished swapping out my mother board and as perfectly as I could reassemble the phone I apparently lost one of the coax connections = no wifi. Went back in and this time the black cable somehow got caught under the camera board instead of on top and connected. Easy to see why this was missed because it looked connected.. well looked like it belonged where it was (wrong)
Anyway that's my wifi fix story - hope it helps someone

[Q] No 3G/4G Signal, Possible Hardware Issue

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

[Q] wifi and 4g reception issues after teardown

Hi guys, hoping someone can give me some help with my phone problems.
I have a verizon s4 that was working perfect other than having a cracked lcd. I took apart my phone and unplugged all the flex cables and antenna and removed all the modular pieces on the phone then replaced the lcd/digitizer assembly (didn't use heat). When I finished my repair and put everything back together, the phone appeared to work fine at first, but I soon realised my wifi performance was really bad (1 bar 5 feet from router) and also my 4g was being weird (if it goes under 2 bars, it stops working and eventually after a few minutes shifts to 3g where it does work fine) I took the phone back apart to see if I missed anything, but the antenna are both plugged in properly and all the flex are plugged in.
Does anybody have any ideas?

8
I think I have figured out my problem, but I am not sure how to fix it. Hoping someone can help. I had an antenna contact bent over. When I went to bend it it broke the top portion off.
Any idea on how to fix or replace it? Also where to get a replacement part if needed.