Does anyone know power pinouts of dell dss 2500 motherboard. Specially SYS_POWER_CONN. In owner manual it doesn't say anything about pinouts signal. Please help
Can I ask what the end goal that you're trying to achieve is? There may be an easier way to get there. The specific information that you're looking for isn't information I can access, but I'd like to still help, if I can.
For something like that, I'd need access to a motherboard schematic. Unfortunately, I don't have access to one, though. The only suggestion I can make would be to see if the board has the SYS_POWER_CON rail identified in print, then follow it with a multimeter in continuity mode. Looking at the board options for the system, it looks like the motherboard is either a Foxconn 1A428PA00-600-G or a Foxconn 1A422JU00-600-G. You might find a board schematic using that, but I can't speak to their accuracy. I say this because our engineers may have made some modifications that might not be reflected there.
I'm curious though, is there a specific reason you want to run the system off an alternate power source? I'm also not sure how successful this would be, because the hardware may not "see" the power supply properly, and I could see that causing you problems.