NVR mainboard USB not work, short?

[stavi]

Hello,

I would like to ask for help to repair an NVR motherboard.
The NVR itself is working fine, but the USB devices are not. No mouse, keyboard, flashdrive, etc. When plugged in, the mouse does not light up either.
I have checked the usb pin, I get a very strange voltage:
I didn't feel much warming (with my hand).
Where do I start troubleshooting? Any ideas?
Unfortunately I am a beginner in troubleshooting, but I can solder

Many Thanks

[ktmmotocross]

Re: NVR mainboard USB not work, short?

your measuring is bad. try again

[stavi]

Re: NVR mainboard USB not work, short?

your measuring is bad. try again

ohhh, you are right
I was dumb negative was taken from the LAN connector (shielding).
I remeasured. Now the voltages are better, but still suspect.

[bbanana]

Re: NVR mainboard USB not work, short?

Try to remove or replace U6, hope you be lucky

[ktmmotocross]

Re: NVR mainboard USB not work, short?

ohhh, you are right
I was dumb negative was taken from the LAN connector (shielding).
I remeasured. Now the voltages are better, but still suspect.

that measurings of upper connector is ok lower have weird voltage on one datapin /4.1V/

[stavi]

Re: NVR mainboard USB not work, short?

Hi,

You may be right.
What is U6 (LC5)?
Can this be measured? I tried, but I got some very confusing values. When how much, several times.

[harp]

Re: NVR mainboard USB not work, short?

When plugged in, the mouse does not light up either.

Put the mouse into usb port and than do voltage measurement. Is with mouse plugged in still 4.77v on usb connector?

[stavi]

Re: NVR mainboard USB not work, short?

Hi,
I plugged in a mouse and a USB phone charger to 2x usb. The mouse did not light up, the phone did not charge.
The U6 voltage did not change.

[jiroy]

Re: NVR mainboard USB not work, short?

LC5 data sheet ..

[harp]

Re: NVR mainboard USB not work, short?

And what is voltage on usb port power pin when mouse is connected? If you have correct voltage present the mouse should light up. Also, usb charger do not use data pin, so only left is 5v to work... if is not work, then no 5v on port, so trace back where is stuck.
I dont know what is connection of usb and LC5... there are two of them on each side of pcb. Most likely they do not blown together. For now, dont distract with these.

[stavi]

Re: NVR mainboard USB not work, short?

I don't understand
I seem to have the VCC 4,8V. But the mouse does not light up, nor does the phone charge.
I thought the problem was simpler...

[harp]

Re: NVR mainboard USB not work, short?

So, for simplicity use only mouse at time, he is low load device and has led indicator.
If you have some simple cheap mouse it will ok, it is much more simply to open than gaming mouse construction.

Open the mouse, and do measurement on ending point of cable, where entered into pcb, what voltage you have in mouse?

[ktmmotocross]

Re: NVR mainboard USB not work, short?

without data pins comunication, mouse not lit even when u have 5V on VCC pin

[jiroy]

Re: NVR mainboard USB not work, short?

without data pins comunication, mouse not lit even when u have 5v on vcc pin

100%

[harp]

Re: NVR mainboard USB not work, short?

Good to known, thank you!
So I suggest if is led light needed and expected, that do prior simple test of mouse.
Maybe you have just one who need data line to light up...

[ktmmotocross]

Re: NVR mainboard USB not work, short?

Good to known, thank you!
So I suggest if is led light needed and expected, that do prior simple test of mouse.
Maybe you have just one who need data line to light up...

chargers have datapins shorted between them, thats why mouse lid. but USB port cannot have it shorted.

it was very long time ago when i checking it. i think without shorted pins phones take only 0.5A and with shorted pins it can take up to 2A. it was with micro usb. dont checking it with USB-C charger

[harp]

Re: NVR mainboard USB not work, short?

Your theory intrigate me, so I test it.
The data pin floating, not touching neither ground or vcc...
But this is apsolutely irrelevant for test mention before, waiting measurement on wire ends.