iMac 21.5" 2011 USB ports not working -EDIT- HUB1 faulty

[elise_s1]

I'm trying to refurbish an EMC 2428 iMac and almost everything has been fixed.
Unfortunately every other USB port is not working:
#1 (close to the audio sockets) does not detect any device.
#2 is working fine.
#3 is not detecting any device.
#4 is working fine.
on both defective ports (#1 and #3) power is available (5.02 V measured with a multimeter) but neither keyboard/mouse nor USB drives are detected.

Tried all sorts of resets and even reinstalled OS from scratch more than once but the problem is still there.
is there any trick I am missing? Not even sure it is HW or SW related...

Thanks in advance to anybody willing to help me

 

[PaulD-UK]

Check out this thread:

USB, Bluetooth and Isight not working

Thanks for that. It explains why my 2011 21.5" iMac hasn't had USB Hub1 working every since I bought it 'open box' 'all faults' for less than half price in 2012. Everything else has worked fine since then, and it passes the Apple Hardware Test. The USB Device Tree shows the hub, but not the ext...

forums.macrumors.com

 

[elise_s1]

Check out this thread:

USB, Bluetooth and Isight not working

Thanks for that. It explains why my 2011 21.5" iMac hasn't had USB Hub1 working every since I bought it 'open box' 'all faults' for less than half price in 2012. Everything else has worked fine since then, and it passes the Apple Hardware Test. The USB Device Tree shows the hub, but not the ext...

forums.macrumors.com

thank you.
I checked and it looks like it is indeed a hardware fault. Also the SD reader (and imagine IR) is not working. USB HUB1 must be at fault.

now I have to decide whether it is a good idea to take it all apart (again) or not.

 

[USB3foriMac]

thank you.
I checked and it looks like it is indeed a hardware fault. Also the SD reader (and imagine IR) is not working. USB HUB1 must be at fault.
View attachment 1728513

now I have to decide whether it is a good idea to take it all apart (again) or not.

Maybe try to add a hub internally, you could solder it to the Bluetooth card. Pinning is in the other thread. That would give you some ports internally which you might be able to make available externally through cables. Or see my thread about USB 3 for iMac mid 2011.

 

[elise_s1]

Maybe try to add a hub internally, you could solder it to the Bluetooth card. Pinning is in the other thread. That would give you some ports internally which you might be able to make available externally through cables. Or see my thread about USB 3 for iMac mid 2011.

thanks.
now I'm actually thinking what could have possibly failed and whether it will be fixable. On this iMac I wanted it to keep all original and without compatibility issues.

 

[PaulD-UK]

My 2011 21" iMac also had this problem - since I bought it in 2012 for a really cheap price.

When I had the logic board out to fit an additional SSD I had a check to see if it was a fixable problem, but I could see no sign of any obvious failure.
So I continue to use it with only two USB 2 ports to this day.
I use an old Thunderbolt 1 dock to give me additional USB 3 port.

 

[howardc64]

Just fixed a 2011 21.5 with 1 USB port dead. Probably is likely knocked off components during logic board reinstall while swapping HDD for SSD. There is a black rubber tape below the USB ports on the backside (away from facing the screen) with a black foam tape on it. Area is very right during logic board reinstall, mine had crimp mark on the tape and component knocked off below (a tiny (0402?) cap) Solder it back on (I have microsoldering iron + hot air station) and everything works

See knocking off component section here along with other 09-11 21.5 logic board reinstall tricky areas

iMac+Metal GPU - iMac HW Tips

Many guideline exist on internet like ifixit + youtube. Will outline a few tips having done a few of these

sites.google.com