okay 0 photos means 0 help
but it runs fine with 3 cards.
so how about running it with 3 cards and showing info to us.
telling me the cards are at 75c does not tell me what power you are pulling.
do you have a kwatt meter? you should it is under 30 bucks and could do a lot to trouble shoot the problem.
https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU/ref=sr_1_1?fast guesses
1) you have a shit card and 3 good cards.
2) psu has a defect
3) bad riser
4) bad cable
5) 1 card has a bad bios
Test in the following manner
buy a kwatt meter = all miners should own one. it is cheap and save money by solving problems
do one card at a time
run card a on slot 1 and look at kwatt readings take a screen shot of msi afterburner
run card b on slot 1 "
run card c on slot 1 "
run card d on slot 1 "
same card so every card result should look close to the same. if this happens you know the cards are not the problem and the slot 1 is good
you should be close to 200 watts for the one card and the system but let us know exactly what each card reads watt wise.
as it could be over 275 watts with bad settings clocks bios
my guess is the cards are pulling high powerLoud beeping noise continue even after adding the second card, tried with 3 cards running, still beeping sound occurs. It doesn't do any beeping noise when a single card is running.
Unfortunately I don't have any kwat meter but I just ordered one, since I've visited all the stores in my city that sell similar stuff and in none of them I could find any so I just ordered from internet. (should arrive in 2 weeks).
I've tested the PSU with the evga tester by just plugging into it and the fans were spinning, which is fine (in my opinion).
None of the GPU's have modified bios so far, they all run on stock settings.
My guess is that i have ordered bad risers as you've mentioned, because the motherboard that I have GIGABYTE GA-H110-D3A has 1 x PCI Express x16 slot, running at x16 and 5 x PCI Express x1 slots and i have 1X to 16X risers,which means I ordered wrong risers and now have ordered 16x1 (which I already did) and I should receive them in 1 week.
By the way I have these GPU's
https://www.newegg.com/Product/Product.aspx?Item=N82E16814150795&cm_re=xfx_radeon_570-_-14-150-795-_-Product