I've got a small basket of broken MT4GS phones from which I am assembling a small collection of working Frankentouches. On one of these, everything works fine except for the sensors (the accelerometers, the magnetic sensors, and maybe a couple of others). I've had the phone apart and everything visually looks OK (no loose connectors or wires).
Having now done the "dumb stare" troubleshooting technique, I'd like to dive a little deeper. It's not obvious from the previously-mentioned dumb stare where the accelerometer and magnetic sensors reside. Does anyone know? If I can narrow it down to which piece of the multi-part motherboard, that will be progress.
I just bought another used MT4GS and found it had this same problem. That really makes me believe it's some common bad connector or part instead of a handful of unrelated component failures. Anyone got any ideas?
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I had a problem with my touchscreen in my Motorola Milestone xt720. I found it out becouse few areas of screen didnt respond. So i bought the Isopropanol and i washed every single part carefully. After drying and putting parts together it still was the same, additionally I noticed, that when pushing the screen near the ear speaker the touchscreen behaves otherwise, or works as it should. Than i took the parts off again and watched the tape. It was torn (or broken). Than i ordered new digitizer on Ebay. After replacing the digitizer and connecting parts again it doesnt power on, and even do not enter in bootlaoder mode. I think the LCD or any single part isnt connected wrong, becouse phone should vibrate and give sound while staring. What can i do with home remedies? Thank you in advance for the answers
If you were the one who did the assembly yourself, you should be aware of ESD. Have you tried reconnecting the old digitizer? And this time, ensure that you are shielded if you weren't (ESD straps). ESD can turn your unit into one real brick, so be careful.
i think you have bought a different digitizer that is not compatible with xt720,
there are similar digitizer with milestone xt720, like;
motoroi xt720 - looks the same but different hardware.
moto xt711 - looks the same but different hardware.
moto xt701 - looks the same but different hardware.
or maybe you have bought a damage digitizer. :-(
@Similya: I dont think so that digitizer is wrong, becouse it looks not the same at the visual point of the front but 100% the same from the back while watching the touch paths, and the tape with connector. Anyway there is not any other looking like my stock on ebay (mirror effect, and other button icons on the top), and the seller got ~99% positive grades with comments reffering to the "Milestone XT720 Digitizer Auction" as "It fits well and works great", "A++ Grade. Fits fine and working.", etc. So i think i have chosen the good one.
@pakpaker: I dont know what is it but i will google about the ESD, i hope it isnt too late ;/
And i cannot connect the old diditizer couse i threw it to the trash after comparison to the new one. Should it start when i just disconnect it and run?
edit: ok i know what ESD straps are, but i was replacing some parts in phones without it and everyone works fine ;/ and the digitizer looks more like the 701 / 711 one but everyone who is selling them says that fits to 720 and customers who buy it gives positive opinion and comment like "it works well". So what is going on? If it is not the proper one, shouldnt it start but just digitizer does not work?
just to make it sure, just bring your phone to a cellphone technician for a better check up. just avoid touching the chips and board. it might catch an ESD from your body. ESD can damage the cpu, ram and all CMOS chips.
by the way, what rom you are using.?
I was using stock rom 2.1 + root and some mods
Ok i will try to find someone but just cant believe that ESD may cause any damage. It has very high voltage, but extremaly low current, so that charge may not pass over any integrated circuit. I think it is only balancing the charge between item and hand, and those ESD straps protects technician against high current from other items which are working atm ;]
I dropped my phone a few weeks ago, and the touchscreen stopped responding to touches in approximately the top third of the screen. If I run Screen Touch Test on the phone and I scribble all over the screen, my scribbles don't show in the top third of the screen, except where they are bunched together in in three straight lines. Being a noob on xda, I can't post an actual link to an image of this failure, but you can find one at imgur.com/DenQepu&Jj7dq5g
It looked like it was caused by a broken digitizer so I replaced it, but this didn't fix the problem. The second image in the above URL shows the phone in the same test with the new digitizer. It basically looks the same as the first image, though.
The digitizer vendor shipped me a digitizer which simply didn't work at all, the first time through, so it is possible that they shipped me a digitizer with the exact same issue as the original one. How common is this failure mode? And if it's likely that the new digitizer is fully functional, is there anything else I might have broken by dropping the phone which could be causing this failure? Having torn down and reassembled the phone quite a few times now, I can't imagine what else it could be...
The first thing you should do is check out THIS THREAD. Also I've had Bad Digitizers sent to me from shady vendors. So I would suggest going with a reputable vendor.
Thanks, prboy. I read through the thread, and it suggests it could be a problem with the ribbon cable. It had occurred to me that the problem might be with the cabling, so I have been looking at it pretty carefully. I don't notice anything obviously wrong with it. No tears, and the cable junctions seem to be working nicely, as best my naked eye can tell. :cyclops: No crunching sound when I open the keyboard. All cables were securely affixed to solid components when I first opened the phone, so it's also hard to see how dropping it could have damaged the cable.
All that said, I am a complete noob at this. This is the first time I've attempted such an intricate project. So I welcome critical feedback. Does a cable failure seem more likely at this point, given the touchscreen identical failure with the two different digitizers? Or does identical failure in the digitizers seem more likely?
It's hard to tell given that I don't have the Device in front of me. But that being said. As long as the Digitizer Vendor is reputable. I'd say that the Cable failure is a definite possibility. It would not be unheard of having a Flex Cable failure, even though it looks good. I've had them be bad, and still look good. Were you 100% sure the Digitizers were bad ? Make sure You and the Work surface are grounded. Also wear Latex No Powder Gloves. You will be very happy you did.
Thanks again, prboy. Found an otherwise functional evo 4g shift with a cracked screen on ebay for $25, so I will swap in my screen/new digitzer onto it, and see what happens. If all is well, it was definitely the digitizer which broke. Otherwise, I've got yet another digitizer to return to the vendor, and they will be getting very bad feedback from me. Will let you know how it goes. (After it arrives some time next week.)
Ok kool. Keep us posted
TEAM MiK
MikROMs Since 3/13/11
This is probably a stupid question but I figured I'd throw it out there.
I have installed a Tab 2 into the dash of my car. It is integrated into the dashboard now and wired up to the stereo. I would like to have a dash cam. It would be nice to be able to use the cam already in the Tab 2, since it's just sitting there. But this would require me to remove the cam from the board and make it external. I've watched the disassembly videos and I see that the camera appears to be wired through a printed circuit. So I'm assuming it would be nearly impossible to remove this cam and make a longer lead for it so that I can mount it external to the Tab itself? If anyone knows of any easy way to do this, let me know. I'd like to avoid the expense of buying a dash cam. Also, I don't think I have the space available to plug one into the Tab.
Well, on the P3xxx the _backside_ camera is actually plugged into the motherboard (on the bottom side), though if you want to turn that camera into a "dashcam" that may require some skills on your behalf.
You would need to extend the flat-flex cable from the camera ... either by using a matching socket and plug (possibly hard to find, and you also need to solder leads/wires to the pins that are insanely close to each other) or by soldering leads/wires to the pins of the existing socket/plug or in place of the existing socket/plug (requires way above-average soldering skills as you need a low-temp iron and solder that melts at low temps so you don't burn the plastic of the flat flex). If your skills, and equipment, don't stand up to the task of soldering on a flat-flex (remember, the pins, meaning the pitch between them, are insanely close to each other) you're already out of luck.
However, even if you manage to extend the connection between the PCB and the camera and it does work, the question is: "How long can the "cable" be before the signal doesn't get through anymore". That's more like "trial-and-error" than "something that can be estimated".
Let us assume you manage to extend the interface long enough so you can sneak it through a hole in the dashboard you then need some enclosure for the camera to mount it to the surface of the dashboard ... that either requires you find something that is suitable, or you have a 3D printer to print yourself a custom enclosure.
Going by your post ... I think you shouldn't touch it or even try it - given you didn't even realize that the camera has a socketed connection to the main PCB. You may be better off buying a cheapo dashcam from your nearby supermarket or electronics retailer, that's the better option over possibly damaging the hardware of the tablet while trying your solder skills at it (unless you happen to be skilled in hacking about on hardware)
I did realize it was a socketed plug, as I stated in my post, I watched the disassembly videos and I've seen replacement cams for sale. So yes, I clearly knew that. That was the entire purpose of my post. I was hoping someone had a simple solution, possibly knowing of an extension cable with the socketed plug, but knew that was a pretty long shot, which I also stated in my post. But I was throwing it out there, just in case someone knew of a simple option. No, I do not want to mess around with soldering, at that point it's not worth it and easier to buy another external cam. Thanks anyway.
Hello, everybody! Do you often wonder whether or not your smartphone is survived a drop? Of course if screen is not cracked, and everything else is still works, then you are safe! Well, maybe...
The question now is about internal damage.
I've read a lot of similar threads here about drop damage, internal damage etc. And also read a lot of scientific articles about drop testing of PCB (printed circuit board), to find out how easily some chip on phone motherboard can be knocked out (all of us remember iPhone 6 Plus Touch Disease).
There is also JEDEC Solid State Technology Association's Standard "Mechanical Shock JESD22-B104C". This documents postulates standards of drop testing for consumer electronics manufacturers (who manufacture electronics wit solid state components, such as processors).
And eventually I figured out a number of statements that may help to find peace for all who dropped their phones:
1. If there is no visual damage on your phone, check if everything inside works as usual (to find internal damage):
a. Touch works everywhere on the screen.
b. Cameras works and focuses properly.
c. Speakers (ear and bottom) are fine.
d. Vibration motor sounds as usual.
e. Accelerometer, gyroscope, compass, GPS, cell reception and download speed on cell or Wi-Fi internet are fine.
f. All buttons and ports are good.
If all above is OK, then there may be no internal damage. Keep an eye to your phone a few weeks after, because internal damage (as microscopic cracks in solder joints) could develop itself not right after impact, but during following hours/days/weeks. If it doesn't, then you are likely safe!
Main conclusion: If any internal damage could show up it will definitely show up in next several weeks after drop. If everything is still OK at that time, then there is likely no internal damage.
2. Smartphones internal circuit boards in general are designed to withstand human height drops (1.5 m or 5 ft.). Of course, bad luck happens, and such drops could smash buttons and screen, but in most cases internals of phone will survive. Here we talk about proper manufacturing conditions, proper soldering etc. Drop stress itself not as dangerous for circuit board, as bend stress. Bend stress is the worst for soldered chips. And bended iPhone 6 Plus Touch Problem is the good example of that.
You are welcome to discuss and I will be glad to hear your thoughts and observations!
I'm wondering if anyone knows what these are... I cant find any info anywhere on that particular SMD code. They're on the underside of a MTCD core board and there's a number of them. The burned one has something to do with the LCD backlight/dimming function, as this isn't working after a mishap that led to letting the smoke out. I believe they're either caps or diodes simce there's clearly a polarity marker on them, but I'm kinda at a loss and would really appreciate any light anyone could shine on my problem.
Thanks in advance!!!
Been a while, so I figured it'd be ok to bump. Anyone have any ideas? I'd love to get this thing functioning correctly again!!
How many solder pads? I intrepted the pic of the failed component as “TAK” looked it up here. Keep scrolling. https://smd.yooneed.one/code5441.html
Yeah... I found that site as well. The issue is that there's only two conductors on these components and every part listed there has more. So it's definitely not any of those they have listed.