PINE64
New UBports edition - black screen (backlight) only - Printable Version

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New UBports edition - black screen (backlight) only - BBreeziN - 08-02-2020

I just unboxed my new Pinephone UBports edition today and I was able to get it to boot a couple of times with the software out of the box, but I was getting screen flickering (not the backlight, the whole screen image). After rebooting it from UBports, I no longer get anything on the screen, just a black screen with the backlight on.

When I try booting it, I get the red LED, followed by a white LED, then a green LED, and finally the LED goes out and the backlight turns on Eventually, the backlight will go out and the LED illuminates white.

Any idea what happened here? Do you think the screen flickering was a sign of a bad screen and it just completely went out? Now it won't boot do anything with just the battery anymore, I have to plug in the type C charger to get it to do the sequence I describe above. Did I potentially get a bad phone? Thanks for the help!

RE: New UBports edition - black screen (backlight) only - drpi - 08-03-2020

Flicker is a known problem at boot time.
Keep your phone connected on the charger for some time. Then try to boot it again.

RE: New UBports edition - black screen (backlight) only - BBreeziN - 08-03-2020

(08-03-2020, 03:56 AM)drpi Wrote: Flicker is a known problem at boot time.
Keep your phone connected on the charger for some time. Then try to boot it again.


Thanks for the fast reply, but it's not just flickering anymore, the screen never comes on at all. I left it plugged in overnight, but it still will not do anything (no LEDs, backlight, nothing) without being plugged in. It kind of seems like there are two issues here, the screen not working, and now the battery not charging or working.

RE: New UBports edition - black screen (backlight) only - SwordfishII - 08-03-2020

(08-03-2020, 07:17 AM)BBreeziN Wrote:
(08-03-2020, 03:56 AM)drpi Wrote: Flicker is a known problem at boot time.
Keep your phone connected on the charger for some time. Then try to boot it again.


Thanks for the fast reply, but it's not just flickering anymore, the screen never comes on at all. I left it plugged in overnight, but it still will not do anything (no LEDs, backlight, nothing) without being plugged in. It kind of seems like there are two issues here, the screen not working, and now the battery not charging or working.

Might be a silly question... But did you pull out the plastic tab covering the battery terminals?

You have to pop the back cover and remove the plastic barrier on the battery. Seems like that would cause the screen to not work without the cable and the battery to not charge if it's still in place.

RE: New UBports edition - black screen (backlight) only - BBreeziN - 08-03-2020

(08-03-2020, 09:43 PM)SwordfishII Wrote:
(08-03-2020, 07:17 AM)BBreeziN Wrote:
(08-03-2020, 03:56 AM)drpi Wrote: Flicker is a known problem at boot time.
Keep your phone connected on the charger for some time. Then try to boot it again.


Thanks for the fast reply, but it's not just flickering anymore, the screen never comes on at all. I left it plugged in overnight, but it still will not do anything (no LEDs, backlight, nothing) without being plugged in. It kind of seems like there are two issues here, the screen not working, and now the battery not charging or working.

Might be a silly question... But did you pull out the plastic tab covering the battery terminals?

You have to pop the back cover and remove the plastic barrier on the battery. Seems like that would cause the screen to not work and the battery to not charge if it's still in place.


Yes I did. It was holding a charge, running off the battery, and indicating a 90% battery during the 1 or 2 boot cycles where the screen was actually working. Any other ideas?

RE: New UBports edition - black screen (backlight) only - SwordfishII - 08-03-2020

(08-03-2020, 09:45 PM)BBreeziN Wrote:
(08-03-2020, 09:43 PM)SwordfishII Wrote:
(08-03-2020, 07:17 AM)BBreeziN Wrote:
(08-03-2020, 03:56 AM)drpi Wrote: Flicker is a known problem at boot time.
Keep your phone connected on the charger for some time. Then try to boot it again.


Thanks for the fast reply, but it's not just flickering anymore, the screen never comes on at all. I left it plugged in overnight, but it still will not do anything (no LEDs, backlight, nothing) without being plugged in. It kind of seems like there are two issues here, the screen not working, and now the battery not charging or working.

Might be a silly question... But did you pull out the plastic tab covering the battery terminals?

You have to pop the back cover and remove the plastic barrier on the battery. Seems like that would cause the screen to not work and the battery to not charge if it's still in place.


Yes I did. It was holding a charge, running off the battery, and indicating a 90% battery during the 1 or 2 boot cycles where the screen was actually working. Any other ideas?

Bad battery or the orientation of the battery is wrong maybe. Do you have a multimeter to check the battery and the pins on the phone while plugged in?

If not you could get a new battery to eliminate or more likely confirm the battery as the issue

RE: New UBports edition - black screen (backlight) only - bcnaz - 08-03-2020

Couple of wild guesses :
  If I hold the power button too long on start up I get a red light,
          Usually it starts properly with about a 3  second push.
Also with a small charger the battery can be finicky when trying to recover.
  and the cord that came with it is probably the best to use when in doubt.

Hope maybe that helps.

RE: New UBports edition - black screen (backlight) only - BBreeziN - 08-03-2020

(08-03-2020, 09:50 PM)SwordfishII Wrote:
(08-03-2020, 09:45 PM)BBreeziN Wrote:
(08-03-2020, 09:43 PM)SwordfishII Wrote:
(08-03-2020, 07:17 AM)BBreeziN Wrote:
(08-03-2020, 03:56 AM)drpi Wrote: Flicker is a known problem at boot time.
Keep your phone connected on the charger for some time. Then try to boot it again.


Thanks for the fast reply, but it's not just flickering anymore, the screen never comes on at all. I left it plugged in overnight, but it still will not do anything (no LEDs, backlight, nothing) without being plugged in. It kind of seems like there are two issues here, the screen not working, and now the battery not charging or working.

Might be a silly question... But did you pull out the plastic tab covering the battery terminals?

You have to pop the back cover and remove the plastic barrier on the battery. Seems like that would cause the screen to not work and the battery to not charge if it's still in place.


Yes I did. It was holding a charge, running off the battery, and indicating a 90% battery during the 1 or 2 boot cycles where the screen was actually working. Any other ideas?

Bad battery or the orientation of the battery is wrong maybe. Do you have a multimeter to check the battery and the pins on the phone while plugged in?

If not you could get a new battery to eliminate or more likely confirm the battery as the issue


4.1 volts on the battery disconnected. I plugged in the phone without the battery and see a pulsing 4.2 volts on the pins. Now, for whatever reason, it's powering up again (I'm seeing the LED sequence) with the battery only, not plugged in. I hear the auto focus click on startup too, but still just a black backlit screen, no image.

RE: New UBports edition - black screen (backlight) only - SwordfishII - 08-04-2020

(08-03-2020, 10:24 PM)BBreeziN Wrote:
(08-03-2020, 09:50 PM)SwordfishII Wrote:
(08-03-2020, 09:45 PM)BBreeziN Wrote:
(08-03-2020, 09:43 PM)SwordfishII Wrote:
(08-03-2020, 07:17 AM)BBreeziN Wrote: Thanks for the fast reply, but it's not just flickering anymore, the screen never comes on at all. I left it plugged in overnight, but it still will not do anything (no LEDs, backlight, nothing) without being plugged in. It kind of seems like there are two issues here, the screen not working, and now the battery not charging or working.

Might be a silly question... But did you pull out the plastic tab covering the battery terminals?

You have to pop the back cover and remove the plastic barrier on the battery. Seems like that would cause the screen to not work and the battery to not charge if it's still in place.


Yes I did. It was holding a charge, running off the battery, and indicating a 90% battery during the 1 or 2 boot cycles where the screen was actually working. Any other ideas?

Bad battery or the orientation of the battery is wrong maybe. Do you have a multimeter to check the battery and the pins on the phone while plugged in?

If not you could get a new battery to eliminate or more likely confirm the battery as the issue


4.1 volts on the battery disconnected. I plugged in the phone without the battery and see a pulsing 4.2 volts on the pins. Now, for whatever reason, it's powering up again (I'm seeing the LED sequence) with the battery only, not plugged in. I hear the auto focus click on startup too, but still just a black backlit screen, no image.
Huh weird. I was definitely expecting a bad battery and you just eliminated both a bad battery and an issue with the battery being charged.

I'm stumped especially since its now working. Definitely check the pins again if you run into the issue again.

The only other thing I can think of is a calibration issue eg. the system perhaps thought the battery had afull charge and wasn't charging it and the battery didn't have enough power to boot. If that is the case a few full power cycles/discharges of the battery should straighten it out.

Edit: Sorry, just saw you still have no backlight still. I would try charging overnight again and the stock image and another image booted from the sd card to rule out a bad image. If that doesn't work it is hardware and an RMA is likely needed.

RE: New UBports edition - black screen (backlight) only - wibble - 08-04-2020

Have you tried booting a known stable image like Jumpdrive from the SD to rule out the software as the cause? https://wiki.pine64.org/index.php?title=PinePhone#Flashing_eMMC_using_Jumpdrive

What you're describing reminds me of what some people have reported with UBports after an unclean shutdown - it gets stuck when trying to mount one of the filesystems. They've fixed it by booting another OS on the SD to run fsck on the eMMC filesystems, or to reinstall UBports or another OS on the eMMC. If you want to find out what's actually going on behind the blank screen you can use the headphone socket as a serial console.