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Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 12:25 am
by eraldino
Hello, My Raspberry Pi is a Model B and I'm trying to make it work on my AOC e2239fwt. I have Raspbian flash on my SD card and it boots.

I know of this because I tried plugging the RPi on my Samsung LCD with HDMI and it works. The Screen has display and I was able to boot to Raspbian without a problem but when I go to my AOC e2239fwt (I need this screen because it is touchscreen) there is no display.

I've tried to add this on my config.txt

hdmi_drive=2
config_hdmi_boost=4
hdmi_force_hotplug=1
hdmi_group=1
hdmi_mode=4
hdmi_ignore_edid=0xa5000080

and still the RPi gives no display.

I've tried to list down the problems:
HDMI cable busted = Not possible because it worked on the Samsung
HDMI signal too low = I've tried to boost it to 9 still nothing
RPi did not boot = Not possible because it booted while on Samsung and on SSH
AOC is not compatible for RPi = Not possible due to : https://www.youtube.com/watch?v=bHfulmm7_9E
(a User plugged in the same monitor that I want to use and it worked for him and not for me)

So, Any ideas ? I really need help here I've stayed up 5 hours trying to troubleshoot this darn AOC monitor.

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 4:45 am
by eraldino
Bump

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 6:56 am
by AndyD
Does you AOC monitor work with any other HDMI device (DVD player etc)?

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 8:10 am
by Jim JKla
I don't know about your Monitor specificaly but with my TV using HDMI I do have to have the monitor live and ready on HDMI so that the RPi detects the HDMI at startup.

There was a setting in config.txt (note that was way back using the Wheezy image) that forced the RPi to make HDMI the prefered start. ;)

If the HDMI signal is not forthcoming my TV goes into standby. 8-)

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 8:35 am
by drgeoff
Jim JKla wrote:There was a setting in config.txt (note that was way back using the Wheezy image) that forced the RPi to make HDMI the prefered start. ;)
Isn't that what

Code: Select all

hdmi_force_hotplug=1
which he has already tried does?

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 8:43 am
by RaTTuS
drgeoff wrote:
Jim JKla wrote:There was a setting in config.txt (note that was way back using the Wheezy image) that forced the RPi to make HDMI the prefered start. ;)
Isn't that what

Code: Select all

hdmi_force_hotplug=1
which he has already tried does?
yes that should be fine
I'd remove all the other ones
and get it to boot
then ssh in and have a look to see what tvservice says

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 8:49 am
by FTrevorGowen
eraldino wrote: ...
I know of this because I tried plugging the RPi on my Samsung LCD with HDMI and it works. The Screen has display and I was able to boot to Raspbian without a problem but when I go to my AOC e2239fwt (I need this screen because it is touchscreen) there is no display.
...
AOC is not compatible for RPi = Not possible due to : https://www.youtube.com/watch?v=bHfulmm7_9E
(a User plugged in the same monitor that I want to use and it worked for him and not for me)
...
A "touchscreen" is not necessarily the "same" as a "standard" monitor - whilst the video link to the "other user's working system" does show that it can be made to work it was not clear to me how "exactly" it was connected to the Pi eg. was something more than "just" an HDMI connection needed, did the screen itself need to be configured etc.
Trev.

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 11:21 am
by eraldino
AndyD wrote:Does you AOC monitor work with any other HDMI device (DVD player etc)?
Yes, I plugged in my DVD player to the AOC monitor and it recognized it and there was a display.

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 11:29 am
by eraldino
RaTTuS wrote:
drgeoff wrote:
Jim JKla wrote:There was a setting in config.txt (note that was way back using the Wheezy image) that forced the RPi to make HDMI the prefered start. ;)
Isn't that what

Code: Select all

hdmi_force_hotplug=1
which he has already tried does?
yes that should be fine
I'd remove all the other ones
and get it to boot
then ssh in and have a look to see what tvservice says
Please teach me how to see the tvservices via ssh so we can determine if there is a signal or not.

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 11:31 am
by eraldino
FTrevorGowen wrote:
eraldino wrote: ...
I know of this because I tried plugging the RPi on my Samsung LCD with HDMI and it works. The Screen has display and I was able to boot to Raspbian without a problem but when I go to my AOC e2239fwt (I need this screen because it is touchscreen) there is no display.
...
AOC is not compatible for RPi = Not possible due to : https://www.youtube.com/watch?v=bHfulmm7_9E
(a User plugged in the same monitor that I want to use and it worked for him and not for me)
...
A "touchscreen" is not necessarily the "same" as a "standard" monitor - whilst the video link to the "other user's working system" does show that it can be made to work it was not clear to me how "exactly" it was connected to the Pi eg. was something more than "just" an HDMI connection needed, did the screen itself need to be configured etc.
Trev.
The AOC e2239fwt has the following ports:
HDMI 1
HDMI 2
VGA
USB Port 1
USB Port 2
Touchscreen Port ( USB Male at the end )
Audio Port

The touchscreen feature is plug in play. Similar to a mouse.

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 11:44 am
by RaTTuS
eraldino wrote: Please teach me how to see the tvservices via ssh so we can determine if there is a signal or not.
tvservice -h
tvservice -n -s

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 12:26 pm
by eraldino
RaTTuS wrote:
eraldino wrote: Please teach me how to see the tvservices via ssh so we can determine if there is a signal or not.
tvservice -h
tvservice -n -s
I have run the code via SSH. I will attach the terminal image.

device_name=AOC-2239

Well the code above certifies that the raspberry pi recognizes the e2239fwt screen but still no luck with the display.

Image

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 12:27 pm
by eraldino

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 1:12 pm
by FTrevorGowen
eraldino wrote:
FTrevorGowen wrote: ...
A "touchscreen" is not necessarily the "same" as a "standard" monitor - whilst the video link to the "other user's working system" does show that it can be made to work it was not clear to me how "exactly" it was connected to the Pi eg. was something more than "just" an HDMI connection needed, did the screen itself need to be configured etc.
Trev.
The AOC e2239fwt has the following ports:
HDMI 1
HDMI 2
VGA
USB Port 1
USB Port 2
Touchscreen Port ( USB Male at the end )
Audio Port
The touchscreen feature is plug in play. Similar to a mouse.
Thank you for that info., which clarifies things somewhat. This may be a "silly question" but are both HDMI ports inputs? (If one, for some reason, was an output, and you were trying to use that port as an input .....)
Trev.

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 1:29 pm
by RaTTuS
try adding a
config_hdmi_boost 4
in your config file [then up to 7 if needed]
seven is the max
http://elinux.org/RPiconfig
reboot afterwards

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 1:36 pm
by drgeoff
RaTTuS wrote:try adding a
config_hdmi_boost 4
in your config file [then up to 7 if needed]
seven is the max
http://elinux.org/RPiconfig
reboot afterwards
In the first post the OP wrote:
"I've tried to add this on my config.txt

hdmi_drive=2
config_hdmi_boost=4
hdmi_force_hotplug=1
hdmi_group=1
hdmi_mode=4
hdmi_ignore_edid=0xa5000080

and still the RPi gives no display.

I've tried to list down the problems:
HDMI cable busted = Not possible because it worked on the Samsung
HDMI signal too low = I've tried to boost it to 9 still nothing "

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 11:01 pm
by eraldino
I borrowed a new hdmi cable and i will test it now. I have a hunch that the flat cable hdmi cable im using is the problem. I will still increase the signal of hdmi.

Please dont be shy to post anything you think is wrong so we can narrow down the problems. Thank you so far for everyone in this community

Re: Raspberry Pi Boots but No Display on AOC

Posted: Mon Jul 28, 2014 11:21 pm
by eraldino
Bad news, I tried a new HDMI cable this time a standard one. I was using a Flat High Speed HDMI with Ethernet and still no display.

I've tried tvservice on this new cable and it still recognises the screen as

"device_name=AOC-2239"

Re: Raspberry Pi Boots but No Display on AOC

Posted: Tue Jul 29, 2014 1:49 am
by eraldino
FTrevorGowen wrote:
eraldino wrote:
FTrevorGowen wrote: ...
A "touchscreen" is not necessarily the "same" as a "standard" monitor - whilst the video link to the "other user's working system" does show that it can be made to work it was not clear to me how "exactly" it was connected to the Pi eg. was something more than "just" an HDMI connection needed, did the screen itself need to be configured etc.
Trev.
The AOC e2239fwt has the following ports:
HDMI 1
HDMI 2
VGA
USB Port 1
USB Port 2
Touchscreen Port ( USB Male at the end )
Audio Port
The touchscreen feature is plug in play. Similar to a mouse.
Thank you for that info., which clarifies things somewhat. This may be a "silly question" but are both HDMI ports inputs? (If one, for some reason, was an output, and you were trying to use that port as an input .....)
Trev.
I'm not really sure about that one. I have two cables at the moment and I'm pretty sure they serve dual purposes as either input or output. Though its my first time hearing that an HDMI cable can have polarity (input vs output)

Re: Raspberry Pi Boots but No Display on AOC

Posted: Tue Jul 29, 2014 7:34 am
by RaTTuS
hdmi cables are just that
ports on the display may be input or output..

but what you are seeing is that something is not happy.

Dom - may be able to help

you could try forcing the PRi into a lower display mode [720 ?]

Re: Raspberry Pi Boots but No Display on AOC

Posted: Tue Jul 29, 2014 12:37 pm
by FTrevorGowen
W.r.t. the display having two HDMI ports - even if they're both input ports the display may have to be switched to the correct port before the Pi is powered up (and, possibly, with nothing else** connected to the other port).
Trev.
** that might "demand" use of the display.

Re: Raspberry Pi Boots but No Display on AOC

Posted: Tue Jul 29, 2014 1:28 pm
by eraldino
FTrevorGowen wrote:W.r.t. the display having two HDMI ports - even if they're both input ports the display may have to be switched to the correct port before the Pi is powered up (and, possibly, with nothing else** connected to the other port).
Trev.
** that might "demand" use of the display.
I understand what you are saying. I will also try to change the source from "AUTO" to either HDMI 1 or HDMI 2. I will post updates.

I also tried to PM the guy who posted the video to ask the config.txt that he has, what type of HDMI cable, Connection diagram and etc. So far he only replied once and I've yet to get the answer from him.

Until then I thank you guys again for your help!

Re: Raspberry Pi Boots but No Display on AOC

Posted: Tue Jul 29, 2014 10:24 pm
by eraldino
UPDATE:

I finally manage to make the display work and tested the touchscreen feature everything worked!

The fix:

Set the AOC's source from AUTO to HDMI 1 or HDMI 2 ( Thanks to Trevor for this idea )
Set the AOC's display from 16:9 to AUTO ( I think this is causing one of the problems )

config.txt
config_hdmi_boost=9
hdmi_force_hotplug=1

I plugged in all the peripherals before booting and it worked.

Thanks for everyone's contribution for this!

Re: Raspberry Pi Boots but No Display on AOC

Posted: Tue Jul 29, 2014 10:34 pm
by Jim JKla
This would be a good fix to put in the wiki but there's not a lot of point because the Foundation have decided it's not worthy of a resource link

Of course it's still there http://elinux.org/RPi_Hub ;)