| Maxdamantus | afaik the no-backlight thing is normal. I've always had that when booting. | 03:27 |
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| Maxdamantus | If the device is powered off and I turn it on using the power button, one of the earlier bootloaders (presumably NOLO or something) turns the backlight on. | 03:28 |
| Maxdamantus | Otherwise, if I'm just rebooting, the backlight will be off until something in Linux turns it on. | 03:29 |
| sicelo | what happens - i get NOKIA screen with no backlight, then after a while (a little less than 1 minute), device turns off | 22:32 |
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| sicelo | something weird is happening on my other N900. It's switched off, but will turn on the backlight every so often (as if it will turn on), and then off again | 20:31 |
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| sicelo | no. it's not even waking up fully. it just lights up backlight with nothing on screen, and then turns off a while later | 20:38 |
| sicelo | sixwheeledbeast^: i did. as soon as the battery makes contact, the backlight comes on | 20:41 |
| cmpxchg | but I worry about the backlight and keypads on the PCB | 23:47 |
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| enyc | buZz: humm ... layout different and there si a n issue with voltage for backlight | 17:08 |
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| brolin_empey | If a fluorescent lamp uses alternating current, does that mean that a computer with a display with a fluorescent backlight, such as old computers with an integrated LCD that uses a CCFL backlight, has to convert the AC from the mains power supply unit to DC used by the power input connector of the computer only for the fluorescent backlight to convert the DC back to AC? Imagine if you use an inverter to power such a computer from a vehicle: the DC from the | 13:11 |
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| brolin_empey | vehicle gets converted to AC by the inverter connected to the vehicle power outlet, then the computer PSU converts the AC back to DC, then the display backlight inverter converts the DC back to AC. :-D | 13:11 |
| gillb | Oksana: no backlighting | 01:55 |
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| brolin_empey | joga: I finally opened your link. That forum topic seems outdated. The original poster says viewing a display with a fluorescent backlight is problematic for them. That means they can use an LCD with an LED backlight; they do not need a plasma display. | 16:16 |
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| brolin_empey | What does it mean if my Samsung SyncMaster 275T (not 275T Plus, which already died) model of 27-inch 1920×1200 S-PVA AMLCD video monitor with fluorescent backlight suddenly and unexpectedly went completely blank (black) while I was using it normally and now it appears to still power off and back on normally but pressing all of the buttons other than Power on the front seems to have no effect? It has an internal power supply so I cannot easily try replacing | 14:00 |
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| brolin_empey | the power supply. I cannot see anything on the display at all, which is different than the LCDs I have used where only the backlight died because then I could still see the image on the screen but the image was very dim. I have been using this video monitor since I got it used in early 2010 so I guess it finally has some hardware failure but I would prefer to continue using it instead of it becoming electronic waste because it is still a very nice display | 14:00 |
| brolin_empey | even if it is very thick compared to modern LCD video monitors with an LED backlight. | 14:00 |
| sixwheeledbeast^ | Seem to have intermittent keyboard backlight issue starting is it likely to be the main ribbon again or is there some magnet control for that? | 00:53 |
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| DocScrutinizer05 | sicelo: kbd backlight is unrelated to FPC/flex. It's controlled vy a magnet in display slider that gets sensed by a hall sensor roughly above the "O" key iirc | 07:15 |
| DocScrutinizer05 | otoh kbd backlight gets controlled by 6 of the LP5523 channels, while the remaining 3 channels control the RGB indicator LED | 07:20 |
| DocScrutinizer05 | e.h. fcam might fsck up both indicator light and jbd backlight | 07:21 |
| DocScrutinizer05 | sixwheeledbeast^: it's MCE which controls the backlight, you might want to have an eye on it and what it does (which "files" it reads and which I2C commands it sends to LP5523) - strace might be your best friend | 08:41 |
| DocScrutinizer05 | sicelo: actually what's the problem exactly? "intermittent kbd backlight" sounds like hard to detect since the kbd BL already acts pretty weird in regular operation | 08:42 |
| DocScrutinizer05 | sixwheeledbeast^: MCE will shut down backlight when ambient light is too high | 08:50 |
| Maxdamantus | as for the input used by mce to determine whether to turn the backlight on/off, I imagine it would be the "slide" gpio. | 08:55 |
| Maxdamantus | on the device that I'm currently using, the slide gpio wasn't working from the time I got it, so the backlight doesn't come on, and it doesn't wake up when opening the slide. | 09:00 |
| DocScrutinizer05 | >>[2018-10-21 23:58:14] <Oksana> Screen on, no backlight: N900's display consumes +80mA http://wiki.maemo.org/N900_Hardware_Power_Consumption Does that include power consumption of touchscreen, or LCD screen only?<< good question, prolly touchscreen aka digitizer been not considered. Then OTOH it doesn't consume any noticeable energy afaik | 06:09 |
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| DocScrutinizer05 | nota bene, this is only the display part (light modulation) of a projector. You need the "backlight" too, for that projector probably a RGB laser source | 06:13 |
| Oksana | Screen on, no backlight: N900's display consumes +80mA http://wiki.maemo.org/N900_Hardware_Power_Consumption Does that include power consumption of touchscreen, or LCD screen only? | 00:58 |
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| sunshavi | my n900 has backlight broken on the night in the car, just the keyboard works. It is almost like if I were blind | 22:05 |
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| sunshavi | vajb: my backlight has failed two months ago. On the night i can read anything on my n900 | 03:20 |
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| Maxdamantus | ime the screen is still readable under direct sunlight, where the backlight is pretty much completely ineffective (might as well be off under that condition) | 03:23 |
| Vajb | I guess it is not easy to shutdown n900 backlight | 22:32 |
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| KotCzarny | backlight applet has an option for 0 brighness | 22:32 |
| ff_ | as root echo 1 > /sys/class/backlight/acx565akm/bl_power ; sleep 2 ; echo 0 > /sys/class/backlight/acx565akm/bl_power | 23:05 |
| brolin_empey | On a notebook computer with hotkeys to change the display brightness, do the hotkeys usually work independently of the software currently running? Or do the hotkeys require special support by the software, usually an OS? I have a notebook computer from 2006 at work that I thought has a problem with the backlight of the integrated LCD but maybe someone set the display brightness very dim because I realised after I already came home from work that I did not | 07:30 |
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| Maxdamantus | while I was using it, the display turned off, but the backlight was still controllable using the switch | 09:34 |
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| Maxdamantus | and now when trying to boot, the white LED glows on, device vibrates, backlight stays on, but nothing on screen. | 09:34 |
| Maxdamantus | (again, backlight always on) | 09:45 |
| Maxdamantus | /sys/class/backlight/acx*/brightness | 10:54 |
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| Maxdamantus | Though I guess theoretically it might be logical for it to set it to 0 anyway (eg, if there's full sunlight, which means the backlight is pointless) | 10:55 |
| DocScrutinizer05 | except there's that dynamic backlight control thing that reduces backlight brightness so the brightest pixel in display could actually operate at FFFFFF brightness from LCD even when it actually was darker | 00:08 |
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| CatButts | it shows nokia text onscreen, with no backlight | 19:14 |
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| DocScrutinizer05 | also iirc BM screen backlight is brighter when on charger | 02:14 |
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| DocScrutinizer05 | when display backlight on | 14:47 |
| DocScrutinizer05 | WLAN on - no powersave - 200 mA; Backlight on max +150 mA | 16:30 |
| DocScrutinizer05 | read what I said: associated to AP (very low WLAN power consumption) and with dim backlight | 16:38 |
| DocScrutinizer05 | and you don't know if backlight on or off | 16:41 |
| DocScrutinizer05 | before: worked with unknown usage pattern (most likely WLAN turned off and backlight turned off) allegedly 3 days standby. NOW: reflashed and upgraded to CSSU, on a supposedly broken charger overnight, then in use for at least 6h and now at 13% charge -- "DAMN there is something wrong!!! We should add a warning that CSSU has a bug in charging" ... No Way! | 16:48 |
| DocScrutinizer05 | ((~questionenable hwkb without going through the normal unlock is what I'm looking for)) no, what you're looking for is an alternative to lock, and I still fail to understand the requirements of that alternative. *Maybe* they are: no touchscreen events, no energy waste on backlight | 17:36 |
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| brolin_empey | My N900 is so slow that, after I slide the switch on the side to unlock the computer, I can see the LCD backlighting a blank/black screen before the screen is drawn. I do not notice that on my Galaxy Note 3 but I guess that is partly because it has an LED display. ;-) | 08:23 |
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| Maxdamantus | Hm .. I guess the comment produced by that script could help though, since it says to leave the backlight on to speed up discharge. | 05:30 |
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| DocScrutinizer05 | for e.g. a ebook reader you could configure the reader to show next page (or scroll) via vol+/- for example, and have the text displayed in "mirror display to e.ink" app on e-ink paper (could refresh automatically when the primary display gets refreshed). Then you shut down the primary display by simply setting backlight to 0 and maybe even blank it | 00:23 |
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| L29Ah_ | and shut off the backlight completely when asl shows values over 10klux or so | 05:05 |
| Oksana | Okay... In darkness, have minimum brightness (1), in normal light get brighter together with ambient, in too bright light switch off the backlight (because transreflective?) | 05:12 |
| DocScrutinizer05 | the minimum is "1" in /sys/class/backlight/acx565akm/brightness | 05:39 |
| DocScrutinizer05 | fun factoid re backlight: there are TWO ways to control it: acx565akm/brightness, plus a GPIO or even PWM (I didn't check details) from CPU itself | 05:51 |
| DocScrutinizer05 | the latter == shut off the backlight completely when asl shows values over 10klux or so | 05:55 |
| Wikiwide | KotCzarny: keyboard backlight too, not just notification light. And, it was somehow resolved before, without changing the hardware. | 14:15 |
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| buZz | MCE is responsible of handling display control (active/dim/blank), activity monitoring (keys, buttons), keyboard backlight, ambient light sensor (ALS), LEDs and device mode control. In addition, MCE is responsible for providing interface to proximity, accelometer and vibra devices. | 18:07 |
| DocScrutinizer05 | buZz: you could check the result instead of checking the binary creating results: get a bright flashlight, place it to the ALS (upper left corner in landscape) for as long as it takes to dim the screen and shut off kbd backlight (with brighness set at 4 bars, won't ever happen at 5 bars. a 15s should suffice in this case), then without removing flashlight lock the screen with sliding lockswitch, check the brightness of beathing indicator | 18:58 |
| DocScrutinizer05 | if your NOLO doesn't show the NOKIA screen (without, then with backlight on), yur display is defect | 15:44 |
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| KotCzarny | led backlight under sticky keys would be sweet | 11:07 |
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| sicelo | < KotCzarny> led backlight under sticky keys would be sweet | 11:08 |
| DocScrutinizer05 | Neo900 is planned with 3color backlight and 3 monocrome indicator LEDs next to the leftmost keys | 11:09 |
| DocScrutinizer05 | I'd probably prefer backlight switching from white to orange on capslock and from white to blue on Fn | 11:10 |
| DocScrutinizer05 | who would modify kernel to adjust backlight brightness? | 00:53 |
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| Enrico_Menotti | I have the power button working in my Debian image. Now I'd like to turn on the backlight. I'll investigate, but if meanwhile someone may point me to the right direction, I'd appreciate it a lot. | 17:19 |
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| DocScrutinizer05 | Enrico_Menotti: /sys/class/backlight/acx565akm/brightness | 20:23 |
| DocScrutinizer05 | so you need to check that acx565akm module sourcecode and docs to find what's the location/name of the backlight brightness and power control | 20:50 |
| freemangordon | Enrico_Menotti: there is something like /sys/class/backlight | 20:55 |
| DocScrutinizer05 | though N900 backlight control is particularly tricky on a hw level | 20:58 |
| DocScrutinizer05 | acx565akm as well as CPU GPIO or PWM has control over backlight | 20:59 |
| DocScrutinizer05 | I.E. you can't expect to e.g. install fsodeviced and have a nice GUI to adjust backlight brightness | 21:47 |
| Sicelo | where did he have backlight working? | 21:56 |
| Enrico_Menotti | But I thought it would have been better first to enable power button, so I may shutdown without opening the back cover and removing the battery, and backlight, so I may read messages from the system. | 22:00 |
| DocScrutinizer05 | so you actually already have display working (not backlight though)? | 22:13 |
| Enrico_Menotti | Yes, I have display working, without backlight. I will also try that way. Before that, I'd like to investigate a bit more about message logging. | 22:22 |
| DocScrutinizer05 | when you actually already got a (min)getty on a console and all that lacks is root login (or sudo su -) and the backlight, you fix the login issue and then you find the control node to enable and adjust brightness of the backlight | 23:12 |
| DocScrutinizer05 | this will suffice to find and config the backlight | 23:13 |
| Enrico_Menotti | So next steps: 1. Turning on the backlight (!). 2. Fix keyboard layout. 3. Allow power button to shutdown (!). | 21:48 |
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| Enrico_Menotti | Don't know. The messages stay on the screen just for a while, without backlight. I am unable to read all. | 22:50 |
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| Enrico_Menotti | Yes, it's working. But no backlight. | 23:16 |
| Oksanaa | Internal error. Application 'Email' closed. Such things happen with Conversations, too. Maybe, some other apps, don't remember. And sometimes, the virtual keyboard still shows up when hardware keyboard is wholly (as evidenced by shining backlight) open. | 22:00 |
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| DocScrutinizer05 | if you want to test: make sure battery is sufficiently depleted so it gets charged when you attach charger, and do just that. Then `stop bme`, make sure backlight is on level 5 and always on (to keep system consumption above the level where bq24150 stops charging), then swap battery and `start bme` | 21:34 |
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| LjL | buZz, actually no, it's not *booting*. it reaches pretty much the same stage as with the old battery, and then it dies. except with the old battery, it also lost backlighting before dying, so this battery has some more charge in it | 18:13 |
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| Oksanaa | My hardware keyboard had no backlight. Why could it be? | 11:29 |
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| Maxdamantus | (keyboard backlight and status LEDs) | 11:48 |
| Oksanaa | Huh... One: try to shine a really bright flashlight into it, see if it helps. Is it the sensor responsible for backlight of hardware keyboard? If yes, I have the same problem, but then, I have a paper sticker over the sensor. | 05:54 |
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| DocScrutinizer05 | if not, make sure you run PR1.3 and keep backlight on | 03:28 |
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| DocScrutinizer05 | a way more simple, and obvious cure however would be to never let the consumed current drop below the deactivation threshold of the power bank - simply keep backlight on | 13:31 |
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| DocScrutinizer05 | as I mentioned before, my N900 with PR1.3 never stops drawing a ~150mA even with backlight off, "thanks to" the USB core never stops trying to connect to a possibly attached USB host | 13:34 |
| DocScrutinizer05 | with backlight off | 13:41 |
| DocScrutinizer05 | with backlight on it's ~250mA | 13:41 |
| DocScrutinizer05 | IÜW with backlight on my powerbank could operate this way a 100h | 13:42 |
| Vajb | screen backlight died as with opera hang | 06:14 |
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| DocScrutinizer05 | opera well might try nasty weird stuff to handle orientation and backlight and keyboard in a way not compatible with mce | 06:23 |
| dkbrz | now, how do I manually tur on keyboard backlight? | 21:00 |
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| kerio | echo 255 > /sys/class/something/backlight/somethingelse/brightness | 21:01 |
| dkbrz | /sys/class/backlight | 21:03 |
| dkbrz | /sys/class/backlight/acx565akm | 21:03 |
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