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COM Express type 10 mini carrier board debug

altay , 03-22-2019, 09:55 AM
We have designed an open source and open hardware X-ray imaging platform.
The board consists of two sections a PIC micro-controller and a COMe Type 10 extension board.
Generally speaking, the COMe Type 10 has two USB II, USB III, SATA, HDMI and Ethernet.

We made a prototype and when we powered it up nothing shows up
We guess something goes wrong with design.

Can anybody help us with debugging the circuit?

PS: The design is based on available standard and recommendations

Any help is warmly well received.
Paul van Avesaath , 03-28-2019, 09:13 AM
start with the beginning..
power it up, does it draw current ?
is the current not excessive? meaning that it draws way more than expected.. (check for shorts on the board)
if it is withing limits than proceed,

measure voltages on the board..
are they there and correct?
if yes proceed

check all power point on the board. is the uC running?
is the clock present.. etc,,

and keep going further and further in the design.

good luck!
altay , 03-29-2019, 02:09 AM
I have tested all, I am suspicious to HDMI circuit. Do you have any sample circuit for MAX9406ETM+ ?
robertferanec , 04-01-2019, 06:19 AM
I have tested all, I am suspicious to HDMI circuit
- you can measure HDMI output directly from CPU to see if there is any activity.

Many times, you can send some outputs to serial console, maybe try that. If you do not have access to any serial console, I would try to find a way how to probe the pins which could be configured as UART TX/RX.

PS: be sure, all the oscillators and crystals are working ok. Double check power sequencing and reset sequence.
anovickis , 04-01-2019, 04:11 PM
I'll take a brief look at your schematic - on COMe, most of the problem I have had are in assembly with solder bridges on the COMe connector, and configuring the BIOS settings
however I did build something in FPGA that would sniff the LPC bus and deliver the POST code to led's

When you say nothing happens - does the COMe module receive power, and is reset correct ?

robertferanec , 04-01-2019, 11:56 PM
@altay would it be possible to print schematic into PDF and attach it here?
altay , 04-02-2019, 01:16 AM
@robertferanec please find the attachment. it includes all sections related to CPU.
altay, 04-06-2019, 03:44 AM
robertferanec could you please inform if you take a glance on the schematics?thanks
robertferanec , 04-02-2019, 03:03 AM
What COMe CPU board are you plugging in?
altay , 04-02-2019, 03:21 AM
As a COMe processor we have chosen COMe-mBT10 from Kontron
altay , 04-02-2019, 03:25 AM
More detials:
As a COMe processor we have chosen COMe-mBT10 from Kontron. In order to test it, we purchased a Connect Tech. carrier board (CCG022 COM Express type 10 carrier board). Then we plugged the COM-mBT10 over the CCG022 carrier board and plugged an HDMI cable. When the board is powered, nothing happened. As a second try, we plugged a USB keyboard and this time the boot load screen showed up.
We have tested the same case (an HDMI connection to display and a USB keyboard) with our platform. However, we found nothing showed up even when we plugged a USB keyboard. We have designed our circuit based on COM-Express Carrier Design Guide standard. The power levels (12v, 5v and 3.3V ) are working fine and there is no problem with microcontroller section.
anovickis , 04-05-2019, 11:14 AM
One thing I learned about COMe is all modules are different pinout slightly even though they have the same connector
Can you get the carrier board form Kontron, or did Kontron say the COMe-mBT10 works with the one you have ?
getting it working on a carrier is probably first thing that needs to happen

Second, usually the COMe vendor will provide schematics for the carrier board (but very rarely the module itself)

one of the problems I ran into is the bios on the my carrier wanted to display VGA by default
of course you can set this to something else, but you have to be able to see what you are doing

Hence I added VGA circuit, as the alternatives where to either get custom bios made, or preload the bios settings on a working carrier/COMe combination and then place COMe on our "carrier"

robertferanec , 04-07-2019, 11:25 PM
If you think the keyboard could be a problem, check out BIOS, in some of them there is a setting to enable booting without a keyboard. But this looks more like something else - the module should be able to boot up ... I would start with checking if there is enough power for the module. Double check what current your board is driving - based on the current you can easily see if the board is booting or not even if you do not have HDMI output (for booting board the current is high and it is fluctuating).
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