HDD wont boot mbp 13 early 2011

Im having some issues and im trying to determine which part I should go for, I have a mbp 13 early 2011

1) the HDD wont boot from the HDD bay, but it works on target disk mode in a usb enclosure that I have

2) I have some spare HDDs here, tried 3 of them and none are detected in disk utility on the ML install, all of them are working fine

So do I have a bad mobo or sata cable?

Hardware test passes fine, except the HDD isnt detected

if there are anymore tests or other apps that I should try please let me now

Im leaning towards the sata cable is bad, that would make the 2nd cable in this mbp history

How this happened?

1) I was doing some work and suddenly the mbp stopped responding

2) I left it be for some minutes and had to do a hard reset, since the response was so slow that it wouldnt even let me restart the machine

3) after that it just gave me the folder icon on start up

any help is appreciated thanks

 

Sata cable will be cheaper to replace than the motherboard. I suggest you get another Sata cable and if that fixes it, then you know.

 

a sata cable is going to cost me around R$150, thats U$75

thats why I wanted to know more precisely which is which, given the high failure rate of those cables it wont matter much if I purchase one and keep it. if its a mobo change I dont know what to do, dont want to spend the money on it simply put

actually scratch that price

the cable is U$50 + U$50 for shipping and them we add taxes for more U$50 so total is R$342, not to mention its an used cable

I got a rough estimate from an authorized repair center of apple and its going to cost me around R$400

this is astonishingly ridiculous, if its the mobo, I will have to pay for at least 2h of work (U$100) + U$900, aside the down time, that was half a month the last time I did a mobo swap

simply put if its the mobo, I will use as a desktop till it dies