U4 component is hot

jonlee123

New member
Who knows its component number?

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If you scroll a little further down that same page you will find this
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Teensy 4.1 manufactured after March 2022 has TLV75733P (U4) replaced by NCV8186AMN330TAG, and BAT54C (D1,D2) replaced by BAS40-05V.
and
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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
 
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.
 
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.
 
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.
 
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.
 
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