Power on normally but no charging

Hi friends, I have here a NS which normally power on but do not charging. I can use it till battery is empty. I have checked for shorts and found on capacitor around M92T36 and on the BQ42193. So I have unsoldered the BQ, the Pi13USB and the M92 but still same. The value is still around 40ohms. Also desoldered the capacitors, they are fine no short. Any ideas?

Connot post picture it says “Sorry, you can’t embed media items in a post.” also link post not possible

You can just break up the url and pose that.

drive.google.c**/file/d/1tBOEKpa9_F5rMHMrI64R5oV3pdEZBQCW/view?usp=sharing

drive.google.c**/file/d/1DyAqakloMKqHGmB2gYZrP_w6MC2bfWyT/view?usp=sharing

You have to exchange the ** to om

Found that the fuse directly behind the usb-c port is blown

I would check the port inside if any pin bent together. Your short is on Vex which comes from M92t and those 3 mosfet below it. check if any short after fuse replaced

Thanks for reply. I have unsoldered 3 mosfets still about 40ohms. Also unsoldered the small 3 leg fets and the bigger on above, still about 40ohm. After that I changed the fuse, still not loading. Then I changed the usb-c port, the port was looking good but anyway better to change. Now this is a short on same place, about 4 ohms. Fuse still ok if plug in normal usb cable. When plug in it alternates in 1 second between charge not charge. If plug in usb-c cable adapter → fuse blown. After all that unsoldered the M92 but short still there. Console is still running with battery. Any ideas where the short is coming from?


Hello, try to unsolder the little fuel gauge ic. I’ve experienced when this ic is faulty or not proper soldered it can cause shorts around bq chip, false charging or no power on.

You mean this part?

Yes, it’s a battery management chip, it could be the problem.

unsoldered, still short, Unsoldered once again the BQ241 still short. Unsoldered


PI13, M92T ans all ic’s around still short. Looks like I have unsolder all parts

As far as I remember the rail which your highlighting on the cap near BQ is also VIN for the DC0 IC on the otherside of the board

That being said, I’m not sure that that’s your primary issue, might also be worthwhile measuring your other primary rails at the inductors surrounding the main PMIC as well as 3V3PDR and SYS rails and posting your measurments to ground, if your not sure you can search the forum - I’ve covered it a bunch of times :+1:

First I did today was solder back all the components and check the console if still works. Works with same charging fault. On the fuse behind the usb-c port if console is running and charger plugged in, it shows 5v for 3 seconds then goes to 0,7 for 3seconds and so on. For yourr readings I#m not sure where to read you mean this picture? For further testing I have also a external PSU ans also an older “seek thermal cam”. Maybe it is a good idea to solder a wire to the shorted cap and go with some volts and check with the cam where the short is?

I found this picture. The 1,8V rail is 0V, the 3,3V rail alternates between 0,1v and 5,2V, the 4V is 3,7V and 5V rail is 0V. Tested with battery and plugged in 5V charger
Voltage

Short is found. Changed the cap short is cleared. Now it is loading perfectly. I measured about 5uF I think it is a 4,7uF Voltage unknown maybe 10V. Swapped from a daughter board.
IMG_0001

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