What happens if you connect the keyboard to a computer via the ''USB to host'' connection? Does the computer recognize the keyboard's USB connection?
Here's an image taken from the service manual that shows the 2 USB ports on the keyboard.
[image|1462216]
(click on image to enlarge for better viewing)
The USB to Host (green box on image) is used when connecting to a computer and the USB to Device (red box on image) is used when connecting a flashdrive etc.
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This is because when connecting using the ...''to Host'' connection , the "host" or computer supplies the power, but when connecting using the ...''to Device'' connection the keyboard supplies the power.
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This is because when connecting using the ...''to Host'' connection , the "host" or computer supplies the power for the USB controller in the 'host", but when connecting using the ...''to Device'' connection the keyboard supplies the power for the USB device.
''If the USB to Host doesn't work either'' then there is a problem with the USB controller section in the DM board or a problem in the DM board.
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''If the USB to Host works OK'' then there may be a problem with the USB Bus Power controller IC 312 (5P), the +5VDC power supply to the controller or perhaps even the USB port itself. Have you visually checked the USB to Device port enclosure to see if all the pins are there, that they are straight and parallel with each other and that the port is free from dust or lint etc?
+
''If the USB to Host works OK'' then there may be a problem with the USB Bus Power controller IC 312 (5P), the +5VDC power supply to the USB Bus power IC or perhaps even the USB port itself. Have you visually checked the USB to Device port enclosure to see if all the pins are there, that they are straight and parallel with each other and that the port is free from dust or lint etc?
Presumably you are using the procedure as shown in the image below when connecting a flashdrive? (and the phone - the phone is just to see if power is being supplied by the USB port as you may not be able to tell with a flashdrive if it has no LED display to show power.)
Hi @ Akram Arabi,
What happens if you connect the keyboard to a computer via the ''USB to host'' connection? Does the computer recognize the keyboard's USB connection?
Here's an image taken from the service manual that shows the 2 USB ports on the keyboard.
[image|1462216]
(click on image to enlarge for better viewing)
The USB to Host (green box on image) is used when connecting to a computer and the USB to Device (red box on image) is used when connecting a flashdrive etc.
This is because when connecting using the ...''to Host'' connection , the "host" or computer supplies the power, but when connecting using the ...''to Device'' connection the keyboard supplies the power.
''If the USB to Host doesn't work either'' then there is a problem with the USB controller section in the DM board or a problem in the DM board.
''If the USB to Host works OK'' then there may be a problem with the USB Bus Power controller IC 312 (5P), the +5VDC power supply to the controller or perhaps even the USB port itself. Have you visually checked the USB to Device port enclosure to see if all the pins are there, that they are straight and parallel with each other and that the port is free from dust or lint etc?
Presumably you are using the procedure as shown in the image below when connecting a flashdrive? (and the phone - the phone is just to see if power is being supplied by the USB port as you may not be able to tell with a flashdrive if it has no LED display to show power.)
[image|1462219]
(click on image to enlarge for better viewing)