Monitor connection issues

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Adrianop
Posts: 7
Joined: Sun Feb 27, 2022 8:37 am

Monitor connection issues

Post by Adrianop » Sun Mar 06, 2022 8:20 am

Hi!
I'm having quite some trouble getting my monitor to work with the buildbotics controller.
I have tried just about every combination of settings in the boot/config.txt file as suggested by several forums. For instance here: https://forums.raspberrypi.com/viewtopic.php?t=166650. And here is the link to the official documentation: https://www.raspberrypi.com/documentati ... g_txt.html.

The backstory/what I've tried:
My monitor is a fairly old BenQ GL2250 with inputs for only DVI and VGA. Therefore, I first tried to use a short HDMI to DVI adapter with a DVI to DVI cable going to the monitor. I could only get this working with "hdmi_safe=1" in the config.txt-file, but this made the display only show 640*480 px in a weird format, but I couldn't get it working with any other setting than just pure safe-mode, not even setting the exact same settings as hdmi_safe=1 means, parameter by parameter (see documentation for details). "Not working" being the monitor remains blank and says "no input".
Moving on, I tried to fix it with buying a HDMI to DVI cable instead. This worked partially yesterday (full 1080p resolution except for a dark region on the left hand side). So I tried to change the overscan parameters in the config.txt-file to combat this, but after changing this, at some point, the monitor wouldn't work again.
So, after that I tried changing a bunch of parameters again to no luck and even switched back to the DVI-DVI cable with the adapter, but to no luck (not even with hdmi_safe=1).
I've tried the monitor with my laptop and the DVI to HDMI cable and it works just fine.

So status quo is that the video output never works now.

This has been super frustrating and I feel like I've tried every trick in the book, but if someone has any tips on what to try next, that would be great.
Could it be a hardware issue? (I have triple checked all the connections)

All help is very much appreciated,
Adrian

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Doug
Posts: 343
Joined: Fri Feb 02, 2018 4:56 pm

Re: Monitor connection issues

Post by Doug » Sun Mar 06, 2022 8:19 pm

Do you have another monitor that you can try with the BB Controller? Preferably one that does not reqjuire an adapter.

Also, I ran the 'vcgencmd get_config int' command and got the following result.

arm_freq=1200
audio_pwm_mode=1
config_hdmi_boost=8
core_freq=400
desired_osc_freq=0x36ee80
disable_commandline_tags=2
disable_l2cache=1
enable_uart=1
force_eeprom_read=1
force_pwm_open=1
framebuffer_height=720
framebuffer_ignore_alpha=1
framebuffer_swap=1
framebuffer_width=1280
gpu_freq=300
hdmi_force_cec_address=65535
init_uart_clock=0x2dc6c00
lcd_framerate=60
over_voltage_avs=62500
over_voltage_avs_boost=62500
pause_burst_frames=1
program_serial_random=1
sdram_freq=450
temp_limit=85

This works on my monitor. So some of this data may be helpful. Notice that the height is 720 and the width is 1280.

Also, here is the content of my /boot/config.txt file. This is the default.

Code: Select all

# Dynamic clock
nohz=on

# Faster boot
dtparam=sd_overclock=100

max_usb_current=1

config_hdmi_boost=8
Finally, here is another link to some useful information that may help.
http://wiki.sunfounder.cc/index.php?tit ... spberry_Pi

Hope this info is useful.

Adrianop
Posts: 7
Joined: Sun Feb 27, 2022 8:37 am

Re: Monitor connection issues

Post by Adrianop » Sat Mar 12, 2022 1:55 am

Hi, Doug and thanks for your reply.
Late last evening I eventually had some time on my hands to try with different monitors on the buildbotics controller.
I tried a total of five different monitors and couldn't get a single one of them working. 3 of them were older displays using the HDMI to DVI adapter, but I also tried with a small HDMI touch-screen and even dragged down the TV to the garage to try something without any adapters involved. Unfortunately none of the monitors worked (the screen remains blank and says "no input detected"), neither with default config.txt or with hdmi_safe enabled.
I am now unfortunately suspecting a hardware issue on the pi. Especially due to the fact that is was partially working at one point (ref. my previous post). Are you able to send me a new controller or potentially a new pi that is flashed correctly? I have already spent way too much time trying to fix this.

Thanks,
Adrian

User avatar
Doug
Posts: 343
Joined: Fri Feb 02, 2018 4:56 pm

Re: Monitor connection issues

Post by Doug » Sat Mar 12, 2022 4:48 pm

My partner is in Finland. I sent him an email message asking him to contact you at the phone number you provided with your order. Hopefully, he can help.

If he is unable to call you, we could set up a video conference via Google Meet.

In the mean time, are you aware that the RPi will not see or respond to the monitor unless the monitor is connected and powered up when the BB Controller boots?

Doug

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