iMac A1311 no USB port and displayport

[dclass-pro]

Hi all guys, I received this imac in which the usb ports don't work, all of them and if I connect the displayport without the internal monitor, I have nothing on the video output.
If I connect the original internal moditor, the imac turns on and works correctly and hangs on the login screen because the keyboard and mouse do not work to enter the password.
I have 5v on the usb ports, in fact the led lights up on the mouse but it doesn't work. Do you have any advice?

[AL._.EX]

Re: iMac A1311 no USB port and displayport

https://www.badcaps.net/forum/showth...light=820-3126

[dclass-pro]

Re: iMac A1311 no USB port and displayport

https://www.badcaps.net/forum/showth...light=820-3126

hello i checked the link, but they ask for schematic and boardview... i have everything i want help on the repair

[stormanimal83]

Re: iMac A1311 no USB port and displayport

Solution 1: Reset the SMC

The SMC (System Management Controller) controls how your Mac's power is distributed to the USB ports. Therefore, resetting it will likely rectify the problem when one or all the USB port are not working.

The way to reset the SMC differs among Mac models. Here is how to do it on a MacBook, MacBook Air, and MacBook Pro:

Shut down your Mac.
Make sure your MacBook is connected with power.
Press the Shift + Control + Option + power button simultaneously for a few seconds until the light on the power adapter changes color or blinks.
Press the power button to turn on your Mac.

Now, you can plug a device into the USB port to see if it's functioning. If resetting the SMC didn't do the trick, move on to reset the NVRAM.

Solution 2: Reset the NVRAM

The NVRAM (Non-volatile random access memory) can fix MacBook Pro/MacBook Air/MacBook USB ports not working issue since it holds data about the USB components, keyboard, mouse, trackpad, etc. But bear in mind that you need to reset some settings such as date and time preferences after resetting the NVRAM.

If none of these works, check if you've missed a major macOS update that may help fix the unresponsive USB ports. If updating macOS still can't enable USB ports to work on your Mac, it's time to contact Apple support.

Have u tried this?
The 5 Volts is not the Problem because present. u got problems with data lines for sure....

[dclass-pro]

Re: iMac A1311 no USB port and displayport

Thanks so much for all the pointers but none of them worked. I need help repairing the motherboard

[Francisco.s]

Re: iMac A1311 no USB port and displayport

Thanks so much for all the pointers but none of them worked. I need help repairing the motherboard

Try to measure all usb data lines in diode mode, perhaps there are a short in one of them.

There are two USB HUB that can be damaged and block usb comunication, test it in diode mode and voltages in relevant pins. Also a ir camera can help.

You could also test with another bios (U6100) with no passwords, and let it load osx.