Question Secondary psu wont turn on under load

[A00]

Hello
i have 2 power supplies connected to each other with add2psu the first one powering motherboard and 3 cards and the second one for other 4 cards
when i disconnect everything from second psu it will power on (with nothing attached at all only add2psu )
but when i connect even 1 card (an 8 pin for gpu + a sata for riser - gpus are rx580 undervolted using 90 watts each but not sure about amount they require at bootup ) it wont power on .
excuse my bad English and Thank you in advance

 

[Lutfij]

Make and model of the two PSU's?

 

[A00]

Make and model of the two PSU's?

its a local made one 800 watt 80+ gold
2 psu exact same model

 

[DSzymborski]

its a local made one 800 watt 80+ gold
2 psu exact same model

Be specific. These questions are asked for important reasons. Incomplete information results in vague, unhelpful answers.

 

[AntonyLovric]

Do you have another PSU for testing / replacing with the 2nd one?

Sounds like the second PSU isn't able to handle the load.

 

[A00]

Be specific. These questions are asked for important reasons. Incomplete information results in vague, unhelpful answers.

sorry and thank you sir i ll keep that in mind
its product of Green company
atx form factor
800 watts 80+ gold

https://imgur.com/a/RSxhlZ8

View: https://imgur.com/a/RSxhlZ8

 

[A00]

Do you have another PSU for testing / replacing with the 2nd one?

Sounds like the second PSU isn't able to handle the load.

i tried it with 1 card only (an 8 pin for card + a sata for riser) it didnt work
could it be the riser drawing much power from sata thats rated 54 watts max?

 

[AntonyLovric]

i tried it with 1 card only (an 8 pin for card + a sata for riser) it didnt work
could it be the riser drawing much power from sata thats rated 54 watts max?

I don't know. Can the 2nd PSU power a computer on it's own?

Antony