I had my N7 screen broken and the bezel damaged and i have had it lying around for about a year now. I finally replaced the screen and bezel on my tablet but it won't turn on any more. Looking for some info on how to troubleshoot what's the issue. What I've done so far is:
Checked that the battery seems to be fine and charged. Using a multi-meter on the battery connector gives a 4.15 V reading. The connector is properly connected (I get the same 4.15 V on the places where the battery connector socket meets the motherboard).
Changed the ribbon cable after finding out that the battery seems to not be at fault. This had no effect.
Tried to put back the old broken screen and bezel to see if maybe the new ones are damaged. Last time i used the tablet with the still broken screen it was able to power on and boot. Now after the fix using the old screen and bezel didn't work.
I have tried to hold the power button with or without holding the volume down button for various amounts of time with no effect.
As i see it now there are a couple of equally plausible things that could have gone wrong.
I have both damaged the new and old ribbon cable while changing the screens.
There is still something wrong with the power circuitry despite battery being at healthy 4.15 V.
The new bezel and screen that came from e-bay were damaged on arrival.
I have damaged something else while changing the screen.
Any ideas on how to troubleshoot any of this?
rihardsk said:
Checked that the battery seems to be fine and charged. Using a multi-meter on the battery connector gives a 4.15 V reading. The connector is properly connected (I get the same 4.15 V on the places where the battery connector socket meets the motherboard).
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Now some 24h later i'm getting 3.8 V. Which according to this http://forum.xda-developers.com/showthread.php?t=2195070 corresponds to battery being at about 60%. Could it be that the tablet is powering on but the screen stays off due to a damaged LCD ribbon cable? Is N7 in general able to boot up with a damaged LCD ribbon cable?
Related
Hi,
I used to have a 1800mAh battery for my JAMin (an aftermarket Ebay one). I made the mistake of sending my device for repair (screen replacement) with that battery and got a 1200mAh battery back (well - I should have seen that one coming). To cut a long story short - ordered another one. This one looked OK so I put it in my JAMin and it was OK for one day. I then put it to charging (second charging) and suddenly the device had a soft reset and would not come out of splash screen. I picked it up and the battery cover felt hot. I opened it and the battery was very hot on one side. Took it out and put it in a safe place but it would not cool down. I was concerned it will catch fire so I opened it and disconnected one wire going from the battery to the PCB inside. It then cooled off (the PCB was hot - not the LiPo cell). I connected the wire again and it seemed to be OK now but I was not willing to risk it again. I opened one of the 1200mAh batteries I had, thinking about switching just the control PCB. The original battery had a better looking PCB (more professional looking) so I connected it instead of the original PCB. I put the battery back in but now it shows 0 capacity all the time, will not go out of splash screen without a charger connected (WinCE low battery protection??). I know the control PCB has a device with EEPROM and RAM inside so my thoughts are that the RAM must have had a reset when switching cells and needs some refreshing. Any one knows how to do that????
Thanks,
Nir
A few month's ago I'd ordered a LCD screen replacement for my incredible, and so when I got back from work o immediately took out the LCD from the package and started taking out my old broken. For me it was my first time experience replacing an LCD phone screen, anyways back to what I was going to say was when I unplugged the connector for the screen and the motherboard itself, after attempt to plug the connectors back together; the display connector plugged in perfect while the connector for the motherboard didn't do so well. The white piece that covers the PCB Connector, it tears a little bit off and I'd tried to power on the phone, meanwhile it didn't I tried again and things got worst. So I search online for a PCB Connector and see one, so I decided to and try to rip off the PCB Connector and plan to order the PCB Connector. So the part to attempt ripping off the PCB Connector didn't go so well, and stop there before things got worst. Any suggestions how I can replace that? I can't just leave my phone in my room and have to cover in dust. I need my phone back, how can I fix these? I know this thread seems long but I tries but it details for you guys.
So there's lots of questions about bad battery life but haven't found my issue in searches - altho I suspect my issue is a factor for many to some degree.
N4 took a 4' to drop to concrete. Screen cracked. Replaced screen w/no problems. Ran fine for a while on stock 4.4.4. Lollipop comes OTA practically zero day and since the N4 isn't my primary phone I upgrade to play around. Shortly after 5.0, the battery drains and shuts the phone off. I charge it overnight, pull it off, battery is dead, phone shuts down. Will stay on and operate fine on wireless charger but powers down if not connected. Pop off the back again to make sure battery connector is snug and reassemble. Now I've got red light of death. Get Google logo and can boot to recovery options but it just cycles. Disassemble again and ultimately find that the battery pins from the mainboard and their little black housing have come off at some point. Try to solder it back on but there's chips on the back side and there's just no room to get the solder on and pins reconnected. Not w/my skills anyway.
My main question is, has anyone successfully reconnected that annoying mofo? Thinking about skipping the connectors and just soldering wire straight from the battery to the board. I don't see anything in that connector that would be a problem if absent, but any warnings I should know about? Other workarounds?
This is not mission critical, just principle/spite.
Repaired?
gkmocv said:
So there's lots of questions about bad battery life but haven't found my issue in searches - altho I suspect my issue is a factor for many to some degree.
N4 took a 4' to drop to concrete. Screen cracked. Replaced screen w/no problems. Ran fine for a while on stock 4.4.4. Lollipop comes OTA practically zero day and since the N4 isn't my primary phone I upgrade to play around. Shortly after 5.0, the battery drains and shuts the phone off. I charge it overnight, pull it off, battery is dead, phone shuts down. Will stay on and operate fine on wireless charger but powers down if not connected. Pop off the back again to make sure battery connector is snug and reassemble. Now I've got red light of death. Get Google logo and can boot to recovery options but it just cycles. Disassemble again and ultimately find that the battery pins from the mainboard and their little black housing have come off at some point. Try to solder it back on but there's chips on the back side and there's just no room to get the solder on and pins reconnected. Not w/my skills anyway.
My main question is, has anyone successfully reconnected that annoying mofo? Thinking about skipping the connectors and just soldering wire straight from the battery to the board. I don't see anything in that connector that would be a problem if absent, but any warnings I should know about? Other workarounds?
This is not mission critical, just principle/spite.
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So were you ever able to get the connector solder back on? I think mine break because it was to hot when I was removing the battery. My nexus 4 shutdown on me, my battery was expanded. I was wondering why my screen was being pushed out. I wonder if Android 5.0.1 is causing phone to run to hot. Never did this with Android 4.4.4. Hope the connector can be fixed. Maybe I take it to a solder shop.
jameswhite4684 said:
So were you ever able to get the connector solder back on? I think mine break because it was to hot when I was removing the battery. My nexus 4 shutdown on me, my battery was expanded. I was wondering why my screen was being pushed out. I wonder if Android 5.0.1 is causing phone to run to hot. Never did this with Android 4.4.4. Hope the connector can be fixed. Maybe I take it to a solder shop.
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Not yet. I pulled the connector back off and cleaned everything up. I found that even very small gauge solder is too sloppy for the 4 small connections. Not to mention there's chips on the back side so you can't linger too long with heat. So my plan is to try again with some conductive ink and/or gel. If that doesn't work I'm just going to use wires to bridge the battery right to the board. Haven't had time to work on it but I'll follow up here when I do.
Did you get a replacement battery? Lithium batteries can swell because of overcharging. There are definitely more than a few N4 owners who had the same issue. A replacement battery won't solve that problem but it could be more tolerant of it, for a while - and depending on if it was "user error" or a fault in the phone's overcharging protection circuitry. Don't go to the trouble of having someone solder the connector back on with the old battery.
im on lineage os and after around %30 screen starts to blink and if it blinks much it reboot does anyone know a fix to this its really annoying
Re-seat and probably clean the contacts of the cables running across the battery on the backside. Only the battery connector is known to develop bad solder connections, but here probably just the two display cables are affected and somewhat loose, or just the one for the backlight.
Kenan07 said:
im on lineage os and after around %30 screen starts to blink and if it blinks much it reboot does anyone know a fix to this its really annoying
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Battery. This is a common issue on samsung devices, you need to replace your battery.
The removal and reattachment of the second ribbon cable(the first is for usb) may actually fix the screen during a battery replacement.
I changed my battery from 2013 just a few weeks ago. Remaining capacity must've been around 50-60 percent. And it was bulging and rear plate and the touchscreen were bending iutward, too.
But no display issues.
Not even the corona (not the flu) effect some guy in the forum recently experienced, which may have been caused by pressure from the battery. And the sudden disapperance of this effect may have meant that there was a gas exhaust from the battery's two cells, flattening them...
Hi,
Please can anyone tell me whether the little connector on the vibration motor is supposed to be soldered to the motherboard or does it just touch at a certain place?
I've already posted another thread about having replaced the battery but it doesn't seem to charge.
Without going into details all over again, a local repair shop replaced the charging port last week - my phone was returned in seemingly working order but they had assured me a bulging battery was OK. I charged my phone but the battery was draining quickly, which was what led me to research a bit more and discovered how dangerous it can be so I ordered a new one.
In the process of fitting the new battery, I discovered half the screws in my phone missing, no copper tape, plus there is no black rubber cover over the charging port & vibration motor as is shown on the guide for replacing the battery on the fixit.com website.
So I'm wondering if the small square 'connecctor' (?) part of the vibration motor ought to be soldered to the motherboard or is it just normally held in place by the black rubber cover? In my phone now, the 'connector' doesn't stay touching motherboard so I'm not sure if this would affect the phone and stop it from functioning or would it just mean the vibration wouldn't work?
Would this affect whether the battery could charge or not?
(Incidentally, I discovered that the the battery connector was upside down compared to the pictures in the ifixit.com guide (the red wire was nearest to the battery instead of the black wire being nearest) so I was hopeful that by correcting it to match the picture, I would have solved the problem but unfortunately, it didn't make any difference. When I connect a wall charger, the screen just flashes and when I connect it to my laptop, it just gets a blinking white led but nothing more. It seems strange to me that it wouldn't make a difference - is it like a usb-c cable in that it can go either way round?)
The battery seller asked for photos of the new battery in my phone and has now offered to replace it - is this likely to make a difference or is the vibration motor not being attached to the motherboard the cause of the problem?
I'll be so grateful for some help.