Would a reverse polarity CPU EPS-12v connector cause the motherboard to fail as well?
Would a reverse polarity CPU EPS-12v connector cause the motherboard to fail as well?
I received a modular power supply from a friend for my PC project, but he didn't realize those cables aren't standard and provided one meant for another device. I noticed this issue while trying to fix why the computer wouldn't start. I've already swapped out the processor and fixed the power cable problem, but it still doesn't boot. Could the motherboard be faulty?
I WILL SAY NO...
the explanation is this: when you reverse the EPS connector, you create a short between the 12V ESP rail and ground. This causes the ESP ground to float since it's linked with the 12V CPU, which can't return ground to the ESP port through a 24-pin ground connector. Many modern PSUs include SCP protection, so this situation won't allow the PSU to deliver sufficient power to damage the PCB traces. Although it's possible in very rare instances that the PSU or motherboard could be affected, serious damage to the motherboard is unlikely.
"I WILL SAY NO..."
...is a pretty categorical statement of "never".
Later, you state:
" But Its unlikely..."
So...it
might
happen.
And of course, we out here have no idea of the PSU involved here.
There are absolutely crap devices around, that lack the needed protections.
The final statement seems to indicate... Ok..
there are numerous factors that could cause a PSU to damage a motherboard, and equally many reasons why it wouldn’t. Still, keeping safety in mind is crucial—this is why I emphasized the No part. It can’t harm a PSU...
Another point: when a PSU begins or operates in any switch mode, there’s a big current surge on the primary side of the transformer due to high output capacitance (output capacitors). This level is intentionally built into PSU design to detect faults. There are certain thresholds a PSU can identify as a short circuit or a very power-hungry device. If we combine discharged output caps with a shorted 12V rail, a dual-switch forward PSU with 650W capacity would likely produce around 180 amps at the secondary for a very short time—far beyond what’s needed to trigger overvoltage protection.
And since it’s not using a 2000-1700 watt PSU, the OCP won’t activate properly, which is just a probability thing...
Peace.. I’m assuming a lot of things... while actual parameters might differ significantly from what I thought.
Good Day
I experienced a faulty PSU and ended up destroying the motherboard in frustration.
Corsair CX600 green label.
Indeed, a power supply can completely ruin a motherboard.
^ I experienced a comparable issue with nearly every unit from the SMART line by Thermaltake; most of my clients ended up with damaged motherboards and even worse, one had a dead GPU.
The power supply is an "EVGA supernova 650 g+". I'm unsure about the original PSU of the imposter cable. After checking with a multimeter, I confirmed all voltages are correct on the cables I'm using now and replaced the motherboard (the CPU was on the old one but never exposed to bad power). However, the computer still won't start.