Cant connect 2 hdds to same computer, misterious behavior

[kill_us_now]

So, as the tittle says, im not able to connect 2 hdds internally to the same computer, i have got 3 diferent computers and it happens in all 3, everytime i try to connect internally a second hdd it starts to fail( two caviar blue wd,some old ide barracudas, and latelly in 2 brand new barracudas), some of them look like if they spin up trying to initialize then spin off sucesivelly, like not enough power or so.

This behaviour killed already 3 hdds and its really driving me mad, sometimes it even happens with a single hdd conected, i have tried to isolate the issue but i just cant, first i tough it may be the motherboard sata port,a faulty sata cable, a faulty power cable, a faulty hdd,but since the issue happens in 3 diferent computers and even with this 2 new barracudas im really out of ideas, the only thing they got in common is cheap 500w power supplys, but i dont have anything connected to the motherboard other than the basics.

Here is a upload of the last new barracuda when i try to use it as second hdd http://vocaroo.com/i/s0DnI74oyMLp this one woudnt spin off and on, this one

Im out of ideas why i cant connect 2 hdds? shoudnt it be just "plug and play"? what im i missing here? Please help me solve this i already junked 3 hdds cause of this.

[kill_us_now]

i just cant understand how a 500w(supposedly) psu isnt able to supply 2 hdds when there is nothing else conected, motherboard, 2 fans, and a mid range graphics card, thats it, it makes no sense.

It should drag...how much? maybe 200wats at max load? im not planning to buy a new psu anytime soon so i guess i will have to connect only 1 hdd at a time and buy a good psu next time i need it.

[LarrySabo]

If you check the capacitors inside that power supply, you are likely to find some of them with swollen tops or leaky, meaning they have dried out and are not performing their job. The power supply can deliver the voltage but not under load. I've seen the same behaviour when the 110/220v slider switch on the back of the power supply is set to 220v in a 110v environment, but I suspect you are on 220v in Spain so that's not relevant.

[Matth79]

A bad PSU can do harm in many ways, have you seen the "gutless wonders" tested to destruction at jonnyguru?

Spikes at rise, volts of noise, or an old group regulated design that puts the voltages out of spec if the load is not even enough between the 5 / 3.3V and the 12V - since it can only regulate the average, the higher loaded rail goes low, and the lightly loaded rail goes high. Some old designs have a very weak 12V dating from when it only drove the motors.

[mikail13]

https://forum.hddguru.com/viewtopic.php?f=1&t=34263

[kill_us_now]

Hi again guys, i know this post is old but since i found the solution i would like to post it, just in case someone else finds it useful.

Yes! the suspect on psus were right! all the diferents pcs and hdds that failed all failed cause cheap/dated psus!

All those cheap psus that i own are 20+4 pins, i disconnected the "+4" and none of my hdds have failed again, i guess i will have to buy some psus soon, thanks to all for your responses, have a nice day!