New Teensy flashes rapidly 4 times, pauses for 4 seconds, and repeats
- Thread starter Helobro
- Start date
Going by the bootloader chip diagnostics here: https://www.pjrc.com/store/ic_mkl02_t4.html 4 blinks would indicate an issue with the main processor clock.
Which is an odd fault to get on a new device.
No signs of any physical damage to the teensy? It looks like the clock is between the button and the main processor next to pin 41.
Which is an odd fault to get on a new device.
No signs of any physical damage to the teensy? It looks like the clock is between the button and the main processor next to pin 41.
PaulStoffregen
Well-known member
You started 2 conversations. Your other message says the chip is very hot. Is this the same Teensy 4.1 board, or different boards?
To answer only this question, 4 blinks on the red LED (the one near USB connector) means a problem with the 24 MHz crystal or nearby parts. Usually this sort of problem is fixable if you can find and remove whatever is causing the problem. A common issue is corrosive solder flux (usually the type which requires washing to remove the residue and then drying in a low temperature oven to dry away the water). Stray solderer on the nearby capacitors or resistor can also cause this problem.
To answer only this question, 4 blinks on the red LED (the one near USB connector) means a problem with the 24 MHz crystal or nearby parts. Usually this sort of problem is fixable if you can find and remove whatever is causing the problem. A common issue is corrosive solder flux (usually the type which requires washing to remove the residue and then drying in a low temperature oven to dry away the water). Stray solderer on the nearby capacitors or resistor can also cause this problem.
Yeah, plumbing solder is called "acid core". Three guesses why that is.
