Pinecil Broken?
12-29-2020, 01:11 PM
Hello, juste received my pencil (and 2 other for family and friends) yesterday.
Mine worked on a laptop power supply (19V) no problem.
I try it on a usb power bank didn't know if qc3 or something else hit + button.
It seems to heat then a messsage that says low voltage or something, I removed the usb cable.
And back to 19V, nothing on screen. After didassembly I check 3v3, it was 0.7V and it draw 80ma when on 19V.
5v is 4.2v like in the schematics, so I desolder the 3v3 voltage regulator and it draw 2ma.
check continuity betwen 3v3 and gnd and got 5ohms not good, I replace the voltage regulator by a generic LD1117 3.3v.
here the grotesque picture.
![[Image: 1S2-MfsJ1bWqdHaFkLEPkdNFBLiM7zQc5?e=down...5jusharing]](https://doc-0o-08-docs.googleusercontent.com/docs/securesc/c0cbnttudkrboie3gncrla8s8g855eta/1km10pahsl29s624dvrq84g6lm69d8sf/1609267725000/04756135222450595667/04756135222450595667/1S2-MfsJ1bWqdHaFkLEPkdNFBLiM7zQc5?e=download&authuser=0&nonce=vrernhnig700a&user=04756135222450595667&hash=83lbd9vdjpddq8apteadr6eap1kvg5jusharing)
And its back to life sort of, it draw 200ma when idle the other are around 10ma. and the U1 chip FUSB302MPX is extremely hot.
the 3.3V is at 3V and it show 21 V instead of 19 it look "normal" considering the voltage divider.
my next step is to desolder the U1 and check for continuity between 3v3 and gnd but it have to wait until I can get to an air desolder station.
I will tell you that you should'nt try to make it work on 5V, I did it itentionaly but it can happen accidentaly.
I think as it know the voltage some sort of software protection could be implemented to avoid this.
Or I get a bad one, you tell me.
Thanks for reading.
The other 2 are working good.
Mine worked on a laptop power supply (19V) no problem.
I try it on a usb power bank didn't know if qc3 or something else hit + button.
It seems to heat then a messsage that says low voltage or something, I removed the usb cable.
And back to 19V, nothing on screen. After didassembly I check 3v3, it was 0.7V and it draw 80ma when on 19V.
5v is 4.2v like in the schematics, so I desolder the 3v3 voltage regulator and it draw 2ma.
check continuity betwen 3v3 and gnd and got 5ohms not good, I replace the voltage regulator by a generic LD1117 3.3v.
here the grotesque picture.
And its back to life sort of, it draw 200ma when idle the other are around 10ma. and the U1 chip FUSB302MPX is extremely hot.
the 3.3V is at 3V and it show 21 V instead of 19 it look "normal" considering the voltage divider.
my next step is to desolder the U1 and check for continuity between 3v3 and gnd but it have to wait until I can get to an air desolder station.
I will tell you that you should'nt try to make it work on 5V, I did it itentionaly but it can happen accidentaly.
I think as it know the voltage some sort of software protection could be implemented to avoid this.
Or I get a bad one, you tell me.
Thanks for reading.
The other 2 are working good.
