4G9GN SSD/HDD cable E5570

Look for damage that might have shorted pins or wires -- that's the most likely cause of the problem.

zagros123, I had (an still have) the same problem with my E5570. I'll bet you have an M.2 SSD installed and are attempting to add a SATA SSD/HDD, correct? Me, too. Here is what I have learned. I purchased a 4G9GN cable from a place on ebay. It was (just barely) long enough for me to install the SATA SSD drive (WITHOUT a caddy or bracket) next to the M.2 in my laptop. The ebay 4G9GN cable was long enough to reach around the corner of the SSD drive and plug into the motherboard fine. However, I expereinced the same problem you did: the computer simply would not start no matter what I tried, until I disconnected that cable. I then ordered a GENUINE Dell 4G9GN cable from DELL. This cable worked fine electrically. computer started right up, recognized the SATA SSD and everything was GOOD! But there was still a big problem. The GENUINE DELL 4G9GN cable was slightly TOO SHORT, by about 1/4 inch, to actually install the SATA SSD properly in the laptop. It'll only fit in the space when oriented a certain way and the GENUINE DELL cable would not permit that.

So, the GENUINE DELL cable is about 4.4 inches long, works great electrically but is too short.

The Ebay cable was slightly longer, at about 4.7 inches, and permitted orienting the SATA drive in the laptop with an M.2 present and I could fit the back of the computer on fine. However, the ebay cable did not work electrically. I'm looking for a longer DELL cable now. I suspect DELL only manufactured cables just long enough to fit when there is no M.2 installed. If they had made that cable only 1/4 inch longer, it would have been useful also when there was an M.2 drive already present.