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Electronics => Repair => Topic started by: ChronosHD on December 12, 2022, 05:47:19 pm

Title: PC motherboard USB 5v circuit fried
Post by: ChronosHD on December 12, 2022, 05:47:19 pm
Hi Community,

I have unfortunately fried the 5v circuit of my motherboard and when I troubleshooted, I figured USBs work but don't get power, as using an external powered hub awakes them.

I'm comfortable with fixing electronics, but I'm clueless what component to check and replace. I've checked fuses for USB and they show 0 resisrence, I guess that's good.

Can somebody guide me please?

The motherboard is an Asus H110 Intel, from a Asus g11cd desktop.

Much appreciated in advance!
Title: Re: PC motherboard USB 5v circuit fried
Post by: Hamelec on December 12, 2022, 07:06:57 pm
is the via hole burned?
Title: Re: PC motherboard USB 5v circuit fried
Post by: ChronosHD on December 12, 2022, 08:11:11 pm
I don't think so, see zoom in photo attached.
Title: Re: PC motherboard USB 5v circuit fried
Post by: coromonadalix on December 12, 2022, 08:14:54 pm
the black   p 260 written on it  smd part near a capacitor  1st photo    should be a fuse  or a poly fuse / at least seems like a fuse

Check its continuity   ???

Can you dust off over the 2 black ic's near the usb sockets,  cant read them   

thks
Title: Re: PC motherboard USB 5v circuit fried
Post by: ChronosHD on December 12, 2022, 08:55:42 pm
136 bbUJG, is that what you ask for?

P260 conducts clean.
Title: Re: PC motherboard USB 5v circuit fried
Post by: mariush on December 12, 2022, 10:12:14 pm
those bbUJG parts could be ESD protection chips
Title: Re: PC motherboard USB 5v circuit fried
Post by: ChronosHD on December 13, 2022, 05:35:59 am
How do I know if that's the problem, checking conductivity?
Title: Re: PC motherboard USB 5v circuit fried
Post by: ChronosHD on December 13, 2022, 09:38:26 pm
Bump
Title: Re: PC motherboard USB 5v circuit fried
Post by: fzabkar on December 13, 2022, 09:56:44 pm
Those ESD protection parts contain TVS diodes. Check whether any of the USB pins (other than Ground) are shorted to ground.

Measure the voltage on either side of the polyfuse. If +5V is not present, then locate the source of the Vbus supply by performing a continuity test between the polyfuse and the various DC-DC converters. Upload a detailed photo of the motherboard if you need help with this.