Motherboard ground connector not picking on mulitimeter

[Jaegar]

I have an MSI B450m bazooka plus motherboard, had a blackout and didn't power on pc till next day, I use a surge protector of course. Next day when trying to power it up, the pc wasn't powering up at all, I tried shorting the power on pins on the motherboard and still nothing, I also drained the cmos and nothing. I removed the psu tried it and it works. No any signs of burn on the motherboard, I tried testing with multimeter and one of the ground pin connector(ground 17 on the picture) on the board wasn't connecting with the ground (vga plate), while the rest were connecting using the multimeter. Is this noemal or is something wrong with this?

 

[Bill_Bright]

I don't know what you mean by VGA Plate.

I removed the psu tried it and it works.

How did you try it if it was removed?

Note Pin 17 is the return for Pin 16. These are the two pins you can use to test if a PSU is able to turn on, by shorting the two pins. This is commonly called the "paperclip test", as seen here. This test is NOT conclusive by any means. It only tells you if the PSU is able to turn on or not. It does not test to ensure each of the voltages are present or within tolerances. Nor does it test for ripple and other anomalies. If the PSU does not turn on with this test, it does tell you the PSU is bad.

A better way to test a PSU is with a tester as shown in that same link. It still is not conclusive because it only presents a small 10Ω "dummy load" instead of a variety of realistic loads. But it does tell you if all the required voltages are present and (at least with that load) their actual voltages. I keep one of those testers in my tool bag for house calls.

The only way to conclusively test a PSU is with an oscilloscope or dedicated power supply analyzer, under a variety of loads. Since most users don't have access to these expensive pieces of test equipment, or have the necessary training to use them, the next best way to conclusively test a PSU is to swap in a known good one and see if your problems persist, or go away.

I recommend you beg, borrow or steal a known good PSU from another computer, swap it in and see if your computer boots okay.

 

[Redwoodz]

I believe you should not have continuity from + voltage to ground. That would tell you have a short in the motherboard.

 

[ty_ger]

I believe you should not have continuity from + voltage to ground. That would tell you have a short in the motherboard.

I think you will. There is a lot of parallel circuitry that will add up to low resistance.




I wonder how you will know that the PSU is working properly when disconnected. Please describe your testing process.

 

[Bill_Bright]

I think you will.

Redwoodz is right. With power removed, there should be no continuity from +V to ground as that would be a short. It should measure as an open.

There is a lot of parallel circuitry that will add up to low resistance.

Ummm, that is not how it works. In fact, parallel circuits effectively increase the size of the conductor, essentially creates a bigger wire (like 2 stands instead of 1). And a larger conductor results in reduced resistance.

I wonder how you will know that the PSU is working properly when disconnected. Please describe your testing process.

Yeah, this I wondered above too. We need the OP to return with more information.