The USB ports stopped working

hi Dan, thank you for your answer,

I’ll get the USB tester soon and do the test, my other concern is if the logic board is damaged (as you expected, and me too).

Is it possible to solder a replacement chip or controller (ie.,with electronic solderer specialist) instead of get a new logic board? Otherwise I think my best and last solution is to buy a thunderbolt 2 dock

Sure its possible for someone with the needed skills & tools to fix your logic board Vs replacing it.

I would recommend you make sure your power units are correctly matched with the different devices like HD's some use higher voltages which can damage your system (and the device) if used on the wrong device. I would also make sure you have all of the AC plugs plugged into a good surge suppressor or UPS so a power surge won't get though.

hi Dan, thank you very much for your concern,

I am indeed using a ups with a suitable power for all the devices and everything was working normal for years (with the same devices) I just had to move to a different apartment, this is when I plugged all the usb devices to the computer while the computer was turned off (but the devices was all turned on), and when I started the computer, I had the error message (USB device drawing too much power), and since then all the usb went down.

ps. I just ordered the USB tester and it will be delivered within the next 8 days. thank you again for your help.

Now for the logic board (you gave me hope to proceed in this direction), Is there a way for me to determine which chip or part or controller on the board that need to be replaced?.

Also I had a comment on (Apple Hardware Test) , shouldn’t it detect the usb problem? ( because when I ran it it gave me (No trouble found).

To be clear its the mis-match of the AC transformer for the given device that likely killed your system. Make sure they are matched correctly.

As for the repairing... Not so simple to answer as their are still quite a few parts one would need to test out and trace out in the schematics. This is beyond a typical DIY person.

As for AHT... I like the term 'Horizon' to describe this. Just like you can't see over the horizon AHT has its limits!

The horizon for it is the digital side of the system (inner-world) once you get to the outer interface side of the circuit (outer-world) it can't test these things without a loopback tool. Over the years the loopback tool was dropped as it was no different that a known good device or using a USB test tool I pointed you to if the power side of the connection was in question.