U4 component is hot

[jonlee123]

Who knows its component number？

 

[jonlee123]

This is teensy 4.1

 

[kd5rxt-mark]

Who knows its component number？

View attachment 31670

From <this> URL, scrolling down just a little, you'll find the schematic for the T4.1. The schematic shows that U4 is a TLV75733P (5VDC to 3.3VDC LDO voltage regulator).

Mark J Culross
KD5RXT

 

[thebigg]

If you scroll a little further down that same page you will find this

Teensy 4.1 manufactured after March 2022 has TLV75733P (U4) replaced by NCV8186AMN330TAG, and BAT54C (D1,D2) replaced by BAS40-05V.

and

Teensy 4.1 manufactured after March 2023 has U4 replaced by TLV75533P, D1-D2 replaced by BAT54CTB6, and a different SD socket (J2).

I'm no EE, but if the ldo is overheating you might want to look for 3.3V shorting to GND somewhere, a solder splatter or whisker somewhere

 

[MarkT]

Given the T4 takes quite a high current it may be normal for this regulator to run quite warm - its not very big after all.

 

[defragster]

Given the T4 takes quite a high current it may be normal for this regulator to run quite warm - its not very big after all.

There are two T_4.1's on the desk here running QNEthernet UDP sketch and not finding anything over 101°F on either near the LDO. Where ethernet ups the current used. For ref one has a heat sink on from early days and MCU is about 10° cooler than the uncovered one that has a MCU hot spot near 100 and less elsewhere. IR thermometer not point accurate and with ethernet cable header and usbHost pins on one I can't touch them.

I did have two go hot some long time ago and sent them back (original parts config) - but not heard that time ever allowed any look at them. And no idea why those two did that close to each other and none before or since.

 

[PaulStoffregen]

The U4 part in this photo is NCV8186AMN330TAG, because it has 8 pins. The other parts used on older and newer Teensy 4.1 have 6 pins.

 

[Spencez]

Is this a new Teensy? Is anything wired up or was wired up to it? Also, the black foam it comes with is conductive, I would recommend taking that off if the Teensy is powered on with it attached. Not sure if that could cause this but it is something to note.