Eclypse Power on

[svaughn442]

Hi ,

I bought an Eclypse Z7 board with the ADC and DAC ZMOD modules when these were first introduced. With or without the Zmod modules installed I have a problem powering on. I plug in the DC 12V supply and turn on SW1 and nothing happens. I switch it on and off and sometimes the red LED comes on and the board is running. Sometimes I can not get it to come on. I have measured the power adapter and it is at 12V. Could there be a problem with SW1?

thanks

[zygot]

@svaughn442,

I have quite a number of Digilent FPGA boards and a few have developed problems with the main power switch. They use the same switch and it isn't particularly robust. Fortunately, this is very easy to debug as the switches are thru-hole and can be probed. If you can measure the wall wart voltage you can measure the switch voltage on the Eclypse with SW1 in either position. It might be better ( i.e. safer ) to just measure the resistance of the switch poles without power to avoid problems.

[svaughn442]

with power off and measuring with my Fluke 77 meter from the center post to top post reads 160K in either position. from Center post to bottom post with switch off reads 0.1 ohm and  with switch on reads open  

[zygot]

If you flip the Eclypse over so that the power jack is to your left and the PMODs are to your right, there are 3 thru-hole pads going to SW1. With SW1 in the ON position you should read close to zero ohms between the center pad and the pad nearest the board edge. You should read OPEN between the center post and the pad farthermost away from the board edge.This is using the red probe on the center pad and the black probe on the others.

With SW in the OFF position: I get 0 ohms between the center pad and the pad farthermost away from the board edge. I get about 155 Kohms between the center pad and the pad closest to the board edge.

You mention that sometimes the board powers on as normal and sometimes not. It certainly seems as though you have a bad switch. I'd send an email to Digilent sales asking for advice on what to do next.

The power supply schematic for the Eclypse is as 'funky' as the rest of the design.

[svaughn442]

Hi

When I flip the board over and make the same measurements, with the switch on I get about 170K instead of 0 ohms. so I will send a note to the sales  team for a new switch, 

thanks! really appreciate it!

[zygot]

Yeah your measurements aren't very switch-like.

I'd go for an RMA if available. If you make changes to your board there won't be the possibility of exchanging the product. If they replace the board it's only a wait.

[JColvin]

Hi @svaughn442,

I have sent you a PM.

Thanks,
JColvin