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No video signal post-assembly  


Sratekk
Posts: 3
(@sratekk)
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Joined: 2 months ago

Hi all,

I'm reaching out today to see what I can do to get my fabscan pi up and running. I bought the kit of Wotterrot and have been following along with the assembly/soldering videos by René Bohne. Anything else I try to fit in with Fabscan doc

I am done with soldering and wiring, I have flashed the required image for the raspberry pi that came with the kit. But for whatever reason, after I plug in the power brick, there is no prompt to show me everything is powered. I am guessing that the PiHat is not powering the Raspberry PI below it. If this is the case, how should I proceed?

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Danilo0702
Posts: 294
(@danilo0702)
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Joined: 2 years ago

Do you have a raspberry 3 or 4? The RPi4 needs more power

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Sratekk
(@sratekk)
Joined: 2 months ago

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Posts: 3

@danilo0702

I am using at Raspbery Pi 3B. I believe it came in the Watterrot kit.

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leonnoel
Posts: 20
(@leonnoel)
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Joined: 5 months ago

If you look at the raspberry pi board it will show a green led if it is powered.  I highly recommend that you connect the hdmi output to a monitor/tv during this initial phase.  The sd card is actually recorded into 2 partitions during the image writing process. A boot partition which formated with windows format and a rootfs partition in a linux format.  If looked at with the windows file explorer only the boot disk will show files in it. Hopefully you have placed the file "wpa_supplicant.conf" to the boot folder. This will install the wifi parameters and the file will disappear from the sd disk after booting.

In the initial boot process, if you are connected to a monitor, you can see the operation where the rootfs partition  is resized to fill the balance of your sd card.  It will reboot to do the resize operation and then ask you for the computer name "pi" and password "raspberry".  You will be asked to change your password to your choice.  At this point it is configured for the default country setting, etc.  At at this time i suggest that you configure for your country, time zone, keyboard and perhaps boot process where you cam choose boot-up with password or boot directly by typing sudo raspi-config.  Change only those items as the wifi has been configured from the file you placed on the boot partition and everything is configured from the special image you loaded. of course you will then reboot.  At this point you will see the prompt on the monito and type ifconfig to see the wlan0 IP address for this session.  From there proceed to your browser and the calibration.  If at all possible it is nice to have a hdmi monitor attached but no absolutely necessary as you can use ssh for basic operation of the pi.

Good luck.

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leonnoel
Posts: 20
(@leonnoel)
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Joined: 5 months ago

Addendum to the above:  Of course a keyboard must also be attached to the Pi.  After you have verified that you have a wlan0 IP address, edit the default.config.json file and type "sudo apt-get update && sudo apt-get dist-upgrade" without quotation marks and return, then reboot.  Run ifconfig again to verify the IP address has not changed before going to the browser.

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Sratekk
(@sratekk)
Joined: 2 months ago

Active Member
Posts: 3

@leonnoel

Can all this be a symptom if I have soldered the step down transformer the wrong way?

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Danilo0702
(@danilo0702)
Joined: 2 years ago

Reputable Member
Posts: 294

@sratekk I think I can remember. When using it for the first time, I had to connect the Pi directly to the router. Then I logged into the Pi via ssh (with the program Putty) and activated the WLAN under raspiconfig). I don't need that anymore because I have linked the Pi directly to a repeater and it fakes a LAN connection. Lan is 100% more stable for me than WLAN. The Pi has crashed many times. Even if the HAT doesn't work, you should still have a connection to the Pi.
If the Pi sits directly on the router, you should see it in the browser (with the IP) after a restart.

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leonnoel
Posts: 20
(@leonnoel)
Eminent Member
Joined: 5 months ago

I am finally checking the forum.  Does this problem still exist. If so , please tell me what you have as far as the equipment.  Did you buy the complete kit from Watterott with the Raspberry Pi 3 B.  Yes it is very possible to wire the voltage reducer in reverse, I had to look at ir very carefully when I constructed mine last year.  I am assuming you may not have too much experience, this is not a problem -if we continue , you will get more.  First, I recommend that you get a multimeter, if you do not have one, and check the voltage at the output of the voltage reducer.  If there is no 5 volt voltage. remove the voltage reducer.  First we need to make sure the Pi works. If you have a Raspberry Pi power adapter, remove the Fabscanpi hat and hook up an hdmi monitor (your tv to the hdmi port will suffice) and to a keyboard. Also of course you should have your sd card in place.  Assuming it works when powered, you can go through the procedure I outlined above to get the Pi working.  At this point, a decision will be needed either to rewire the voltage reducer properly or an alternative.  I will try to check daily and continue with advice of what needs to be done.  You realize that I am an 84 year old with some knowledge, more than perhaps a newbie but a long long way from being an expert. 

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