How To Fix Samsung S22 Ultra With Red Temperature Warning Symbol

How To Fix Samsung S22 Ultra With Red Temperature Warning Symbol
Device	Galaxy S22 Ultra
Affects part(s)	Main Logic Board
Needs equipment	Soldering Iron, Hot Air Station, Microscope
Difficulty	◉◉◉◉ Specialist
Type	BGA, Soldering

Problem description

Samsung S22 Ultra has a common fault where it will give you a red exclamation mark warning when you plug in the charger.

If the device boots, it will say it's either very hot or very cold & it cannot charge & will shut down. This can happen out of nowhere. S22 Ultra also does not require the wireless coil/back cover to prevent the temp warning, like some of the older models do. A fully working S22 Ultra will charge fine without the wireless coil/back cover.

Samsung S22 Ultra with a temperature warning when charging

This issue lies within the motherboard itself

Symptoms

• Does not charge
• Show red exclamation mark error message

Solution

Diagnostic Steps

Samsung S22 Ultra - Connector Temp Sensor Line that you must check for a short.

Check the 3rd pin form the top right of the charging port FPC (SOC25000). The line is called USB_THM (USB Thermistor) which is the temp sensor line for the board.

The known good reading should be 0.717V

Samsung S22 Ultra - Charging Connector Temp Sensor Line Diagram.

If you get a low reading like 0.003V, then the line is shorted.

Repair Steps

To repair the shorted USB_THM line, you must replace the U7002 IC. This is a PMIC inside the Samsung Sandwich.

Samsung S22 Ultra - U7002 IC that needs to be replaced if USB_THM is shorted

IC name is "Qualcomm PM8350"

This is extremely difficult to do, as the 2 layers are soldered together with lead free high temp solder.

Although, there are a few workarounds to get it to power on & allow you to extract the user data

1. Boot from a DC Power Supply
2. 

   Samsung S22 Ultra - Picture of U7002 IC that needs to be replaced if USB_THM is shorted
   Boot with a fully charged battery.