troubleshoot for 5CSEBA4U23I7N (cyclone V fpga processor)

[ieeeHuseyin]

Hello,

I am trying to troubleshoot a pcb with a 5CSEBA4U23I7N cyclone V fpga processor.

The resistance value I measured between 3V3 and GND for the intact pcb is around 380ohm.

One of the PCBs is drawing more current than normal. When I measure the resistance between 3V3 and GND, it is about 141 ohms.

Then I removed the fpga from the pcb and continued the tests in this way.

I measured the short circuit status of all the pins I used as 3V3 supply in the fpga. Accordingly, the resistance values of some pins are as follows:

FPGA PIN 1	FPGA PIN 2	Value (OHM)
C1 (GND)	AG4 (3V3)	212 OHM
C1 (GND)	AE10 (3V3)	212 OHM
C1 (GND)	AE13 (3V3)	212 OHM
C1 (GND)	AA12 (3V3)	212 OHM
C1 (GND)	V11 (DATA)	215 OHM

According to these values, is the resistance value I measured between the VCC pin of the fpga and the GND pin normal?

If there is a malfunction, what could be the cause? Or how should I proceed?

Note

Below are the measurement results I made with the fpga I removed from a different pcb. Similar results were obtained here.

FPGA PIN 1 (GND)	FPGA PIN 2 (3V3)	Value (OHM)
C1	AG4	291 OHM
C1	AE10	291 OHM
C1	AE13	291 OHM
C1	AA12	291 OHM
C1	V11	291 OHM
C1	AA14	328 OHM
C1	AD13	328 OHM
C1	AD9	328 OHM
C1	AD16	328 OHM
C1	AD18	328 OHM
C1	AD21	328 OHM

[cfkd]

Hi,

Thank you for your question.

Kindly expect some time to hear back from our engineering team about the requested information.

Best regards,

Chee

[cfkd]

Hi,

Vcc to GND is not a resistor; therefore, it does not follow Ohm's law where the resistance is a constant when varying the voltage/current. We do not spec the resistance in our datasheet nor measure it during production test. Kindly let us know if this answered your question.

Best regards,

Chee

[FvM]

You are apparently troubleshouting a problem related ton bank 3B and pin V11 but don't tell what it is. 

Depending on the kind of problem, there can be different ways to narrow it down. Resistance measurement with multimeter usually isn't.

[ieeeHuseyin]

I removed the FPGA from the PCB.

I'm guessing some FPGA pins are broken.

How can I test to detect these?

Is there any document I can reference?

[cfkd]

Hi

To check whether a pin is broken or not, kindly reference this Q and A:

https://community.intel.com/t5/FPGA-SoC-And-CPLD-Boards-And/Broken-Pins-Determination/td-p/727301

Best regards,

Chee

[ieeeHuseyin]

Since the FPGA is not attached to the PCB, I can not power it and test it.

How can I check the status of I/O pins with a multimeter?

Or with a different method.

[cfkd]

Hi,

Thank you for your question.

As the device is not mounted, you cannot test with some logic.

Any tampering with the device not as per the recommendation can void the warranty.

If you would like to test without the power, you will be required to send for RMA process by contacting local Sales for filing IPS case to start RMA.

Best regards,

Chee

[cfkd]

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