Question power supply tester -5v not lighting up

[LLA]

I bought a redragon 850 RGB power supply and my coolmax analog power supply tester indicated a failure on -5v but I cannot find notice of -5v rail listed on power supply. Should I return the power supply to Amazon? It also shuts off when I attempt to separate the 4-pin motherboard plug and plug it into the otherside of the tester.

 

[Dark Lord of Tech]

I would return it for a more reputable brand.

 

[--SID--]

-5v isn't present anymore on any PSU of the past decade or more.

Why do you test a brand new PSU?
Is it this unit? https://redragonshop.com/products/8...ar-rgb-pc-power-supply?variant=43727961424094

 

[BFG-9000]

-5v on pin 20 (white wire) was required until ATX12v v1.2 in 2002 when it became optional, and was deleted with ATX12v v1.3 in 2003--so pin 20 has been empty for more than 20 years.

 

[LLA]

-5v isn't present anymore on any PSU of the past decade or more.

Why do you test a brand new PSU?
Is it this unit? https://redragonshop.com/products/8...ar-rgb-pc-power-supply?variant=43727961424094

looks like; got it at amazon for 50. https://www.amazon.com/dp/B0BBZSPJV5?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

 

[LLA]

-5v on pin 20 (white wire) was required until ATX12v v1.2 in 2002 when it became optional, and was deleted with ATX12v v1.3 in 2003--so pin 20 has been empty for more than 20 years.

Thanks for the information. I have an old 20 pin analog PSU tester. Do you know if I can test a 24pin PSU with it?

 

[BFG-9000]

Sure, except it can't test the 4 wires on pins 11 (12v), 12 (3.3v), 23 (5v) and 24 (ground)

 

[bill001g]

Thanks for the information. I have an old 20 pin analog PSU tester. Do you know if I can test a 24pin PSU with it?

It depends on what you mean "test". Many modern 24 pin power connectors from a power supply can no longer be split into 20 and 4 so you might have trouble physically plugging the tester into the cable itself. If you manage to get it plugged in it should work.

So how does this tester really work. Are you trying to insert it between the motherboard and the power supply or are you testing just the power supply itself on your desk. It takes nothing special to test a power supply. You just need a paper clip and a simple voltage meter.

Testing the power inline is much more of challenge and I would not try to use old test equipment with modern computers. They make all kinds of fancy testing equipment that will actually show you the power consumption on each pin rather than the simple voltage. The price has come way down but really is not something even your hobbyist computer guy would have. It is more a repair shop or maybe someone writing reviews that would need this specialized equipment.