Hello,

Part 1:

my first question is all the 4 wire power connectors (intended for hardisks/dvd drives not mother board) are same. Right? I've been using all of them same and I had no problem for years.

Yesterday I borrowed a SATA disk from my friend and connected it my computer using Sata Power adaptor (4 wire)

and when I switched on the computer. There were fumes coming out of the connector. I immediately turned it off (in just one second).

I tested the voltages in the 4 wire power connector of my SMPS:

They were 5.3v & 12.2V. I couldn't measure the current. But my SMPTS label reads:

DC Output:
3.3v (25A)
+5v (32A)
-5v (0.3A)
+12V (17A)
-12V (0.8A) 

And the SATA hardisk label reads

Input:
+5v (0.72A)
+12V (0.52A)

I'm shocked! I never noticed this. Does the "sata power adaptor" scale down the current to required? If it doesn't, I've been connecting same way for years. I never had any problem. This is the first time I'm encountering it.

Part 2:

I wanted to return the drive to my friend. He has two hard disks, SATA & PATA. Its the SATA that I borrowed. When he usually switches on. The CPU fan starts & then stops for a sec and starts again and continues working. That was the earlier situation. I don't know why it stops & starts?

Well, Now when I connect this SATA disk and switch ON the computer. CPU fan starts (just for an instant, not even a 0.5 sec) and stops. It doesn't start again, I mean the power from SMPS has stopped. But if I disconnect this SATA disk. It works fine.

What seems to be the problem? I've no idea about why there were fumes or why his SMPS starts & stops giving power? What is its relation with the SATA disk connection?