I think I've exhausted my options, hopefully somebody here has an idea.
From day 1, my TF300T has been unable to connect to a PC. At first I thought it was because one of my cats chewed on the USB cable before I could try (it still charged, just no PC connection) so I didn't do anything while it was still under warranty.
Since then, I've tried 3 different cables, multiple PCs and a Macbook, and I can't get anything out of it. It's not detected at all by the computer - no unknown device, no prompt for drivers, no device connected sound when I plug it in. No reaction on the tablet either, whether USB debugging is on or not. I also tried replacing the USB port on the tablet, but got the same thing. I doubt it's a driver issue since I'm not getting anything at all on either end of the connection.
It DOES connect to the dock ok, and all the dock functions seem to work. I've tried connecting the USB cable to both the tablet directly and the dock, and I get nothing from either port.
I'd really like to be able to flash custom ROMs on it, and I can't find a working way to root or flash it without a functioning USB connection. Could it be the third-party USB cables giving me problems, and if so, is there one that actually works? And if not, is this just a lost cause?
Hi everyone. I post this topic in here, because I don't know where else I could do it, because my device is of a not much known brand. I own a Krono Net 1032, chinese tablet, is rooted via magisk, and everything was going ok with it, until several days ago, when I tried to connect from pc, to adb via wifi, but it didn't connect (adb debugging was enabled and adb returned me 10061 error); action that was performed right without any issue till that day. Uneasied, I tried to connect it via usb, but not only won't connect to adb, but it won't be detected as mass storage... even is not detected as anything. Now, really worried, I tried to connect it by changing usb cable... the same; tried connecting on another usb ports...the same; tried connecting tablet on another pc... the same; tried connecting any peripheral via otg... peripherals won't work; I disabled and reenabled adb debugging... the same. It barely charges, but if I move the tablet, stops charging.
The alarming behavior is that, for I could get root access, it should be connected on preloader mode, for can flash it; so if I told you that this tablet is already rooted, is because in the past I could connect it on that mode and my pc did recognize it with such mode. But now, not even pc recognize such connection.
I suspect that is a hardware issue, but I don't know if that could be happening because of usb port solderings or an usb controller ic issue; and I don't want to open it and try to repair, without before read your opinions.
So please ¿What can be happening there?
Thanks in advance for your answers.
Do a Factory Reset.
xXx yYy said:
Do a Factory Reset.
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Click to collapse
I would do, if my device would be detected on fastboot mode or preloader mode, but none of those usb connection modes are detected by pc. So I don't guess it's an operating system issue; or better said, i'm afraid of doing that, and find that it remains the same. But I'll consider it as my last resort (because i've made many customizations that I don't want to lose -root, gravity box, lsposed, etc-). Anyway I think the reason of what could be happening, would be maybe worst than that (I think is a tablet's usb port issue). Thanks for your opinion.
PS: I forgot to say something that confuses me too much but at the same time, gives me hope that this isn't a hardware issue: Wifi adb isn't working too,and something weird, remote control from pc (eg. via teamviewer or anydesk) doesn't work also.
Don't think device's USB-port is defective, that of all things the lanes are broken, but not the power related connections.
I rather think that USB is not configured correctly in Android's build.prop file, expected USB- setting in build.prop always should be
Code:
persist.sys.usb.config=mtp,adb
xXx yYy said:
Don't think device's USB-port is defective, that of all things the lanes are broken, but not the power related connections.
I rather think that USB is not configured correctly in Android's build.prop file, expected USB- setting in build.prop always should be
Code:
persist.sys.usb.config=mtp,adb
Click to expand...
Click to collapse
I tried adding that line, and rebooted the device, but nothing happened, is still without usb support... But wait a moment, about it ¿is there any specific place to paste that line, or can be pasted wherever inside this file
Did you verify that buld.prop got changed?
Not already existing key-value pairs typically are added to end of build.prop file.
Ckeck for existence of these 2 key-value pairs too:
persist.service.adb.enable=1
persist.service.debuggable=1
Does the USB work properly in fastboot?
Renate said:
Does the USB work properly in fastboot?
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Click to collapse
No, is not recognized in fastboot or preloader. That's why I suspect of tablet's usb port, which would be probably the worst scenary to me. The weird thing is, if the suspected problem is related to hardware ¿Why adb via wifi is not working too? ¿Isn't that a routine separated from usb adb? or definitely ¿if usb adb is not working, wifi adb also stops working?
xXx yYy said:
Ckeck for existence of these 2 key-value pairs too:
persist.service.adb.enable=1
persist.service.debuggable=1
Click to expand...
Click to collapse
Yes, they are already written there, but none of the expected happened (which comes alive again its usb port).
If my problem would be hardware related, I mean, if the problem is at the usb port (i think it is, because, despite it charges when cable is plugged, if I move a little the tablet, it loses charge connection. I tried several cables and happens the same), if sadly i'm right, I think that, being positivist, it would be just solderings retouch on the usb port. But investigating, I can see that micro USB type C (female) connector, is not so easy (even is complicated to not say hard) to resolder, so ¿is there any technique?¿Do i need a hot air gun or something like that?¿or is that only solvable by swapping its main board?
Anyway, If my problem is of hardware, none of the options could be nice.
Often the USB connector is on its own little board connected by a flex printed circuit to the main board.
I Googled "Krono Net 1032 USB connector board" and got https://www.aliexpress.com/i/2255799845922187.html
Yeah, it would be great if they were related, but at least you can see what I mean and how cheap it would be if you could find the right one.
Renate said:
Often the USB connector is on its own little board connected by a flex printed circuit to the main board.
I Googled "Krono Net 1032 USB connector board" and got https://www.aliexpress.com/i/2255799845922187.html
Yeah, it would be great if they were related, but at least you can see what I mean and how cheap it would be if you could find the right one.
Click to expand...
Click to collapse
That board seems to be a spare part of a nokia device. It would be very good if only was disconnecting the suspected bad component, and connecting the new one. But I opened this tablet and what I saw, is that seems, that usb port is integrated with the mainboard.
If it were micro USB 2.0 I'd do it myself.
USB Type C on a motherboard I'm sure that I'd destroy somwthing.
Renate said:
If it were micro USB 2.0 I'd do it myself.
USB Type C on a motherboard I'm sure that I'd destroy somwthing.
Click to expand...
Click to collapse
That's my worry, because it's USB type C.
There are two types of Type C connector:
Real, USB 3.0 24 pin
Lite, USB 2.0 12 pin
I'm not sure that I'd even want to tangle with the 12 pin.
I have an update about this topic. Well, I took courage and disassembled as much carefully I could, I tried to get as much tools I could (besides solder iron, magnifying glass, focal illumination, soldering paste, etc.). I could saw that usb socket pins were tiny but accessible, so, also as much carefully I could, I resoldered them, I cleaned them, and reassembled the tablet.
To be brief, after that treatment, the battery charging was more consistent, more stable (now I can move the tablet without losing charging connection) but it still, doesn't want to be recognized by the pc, wheter if it's on fastboot mode, or normal mode (with tablet on). I must clear that my pc, recognizes other android devices that are plugged into it, but this one doesn't. So, that's very wird to me. My only explanation for that, is that its usb controller IC is working bad or could be broken, but if it would be broken, how could be possible, that tablet still can charges its battery? What do you think about it?
PS: I didn't see too much pins, so I think it has 12 pins.
Renate said:
There are two types of Type C connector:
Real, USB 3.0 24 pin
Lite, USB 2.0 12 pin
I'm not sure that I'd even want to tangle with the 12 pin.
Click to expand...
Click to collapse
I was seized by a big doubt since this problem happened. ¿Is wifi ADB bound to usb adb? I mean, if USB ADB isn't working, ¿Does wifi adb stop working too?
Another question is: Before this, I remember remote control worked on this tablet (control tablet remotely), but now there's no way to make it work ¿Can be this related to the original issue?
Even worst ¿Can the initial issue, be related to a ROM corruption issue? I say "worst" because if it is, I don't know how to reflash it without usb support.
No, WiFi ADB should work even if USB is broken.
You should be able to switch to WiFi ADB using a non-rooted terminal app.
You should be able to do this without root.
Code:
$ setprop service.adb.tcp.port 5555
But adbd has to be stopped and restarted. I'm not sure that this works without rooting.
Code:
$ stop adbd
$ start adbd
But you should be able to go to Settings > Developer options > Enable USB debugging and turn it off then on.
Then:
Code:
C:\>adb connect 192.168.1.12345:5555
Of course 192.168.1.12345 must be the actual IP of the Android on your router.
Renate said:
No, WiFi ADB should work even if USB is broken.
You should be able to switch to WiFi ADB using a non-rooted terminal app.
You should be able to do this without root.
Code:
$ setprop service.adb.tcp.port 5555
But adbd has to be stopped and restarted. I'm not sure that this works without rooting.
Code:
$ stop adbd
$ start adbd
But you should be able to go to Settings > Developer options > Enable USB debugging and turn it off then on.
Then:
Code:
C:\>adb connect 192.168.1.12345:5555
Of course 192.168.1.12345 must be the actual IP of the Android on your router.
Click to expand...
Click to collapse
Ok, I did all that, with a terminal emulator. Without root permission, those commands do nothing. So I invocated root access by typing "su" command; then root request appeared, I gave it to the app root access, and then all those commands worked ok. After corroborate the right wifi adb connection (after enable on developer options "usb debbugging" and all those stuff). I tried a remote control program called "scrcpy", and it worked as expected in a normal condition, I mean, I can see on my pc, the tablet's screen and also i can control the tablet from it, but after that , I'm still wondering, why all other remote control programs, like team viewer and anydesk, don't want to control this tablet, hmmm... ¡anyway!
That news in general to me, is an advance, and is good, but i'm still wondering why usb connection isn't responding (mtp, adb, fastboot nor preloader mode) , not even its OTG support and I'm pretty sure this tablet has it, because with it, came additional an OTG adapter, so why would do they add an otg adapter if tablet wouldn't support it?