HI, just finished my K8055N board. Using WIN10, the only LED lighted is LD11.
Voltage on pic pin 1 and 20 are 3.3v.
The voltage over pin 9 and 10 is 0
pin 8 and pin 19 are both connected to ground.
Any help is appreciated.
What is the voltage between pin 9 / 10 and ground?
1.4v / 1.4v I appreciate the help!
Have you checked there is no short circuit between these pins?
Indeed, looks very good.
Please check the resistance between pins 9 and 10.
USB cable disconnected. Should be about 1 mega ohm.
Next test: Please remove IC3 from its socket and measure the resistance between pins 9 and 10 of the removed IC.
Is there any difference if you swap the meter probes between pins 9 and 10 of the IC?
Please measure also the resistance between the IC socket pins 9 and 10.
I discovered the resistance my Fluke was showing is inaccurate. I’m going to redo the resistance tests. Sorry!
9 & 10 = 433K
9 and 10 of the removed IC. = 12.32 M ohm
Resistance between the IC socket pins 9 and 10 = 0
Swapping the meter probes between pins 9 and 10 of the IC. = pin 9+ = 12.19m pin 9 - = 12.32m
Thanks again!
=
Thank you for the updated results.
It seems the IC3 is OK.
There seems to be a short circuit between pins 9 and 10 on the board.
The problem is either an invisible short on the board, defective crystal X1 or maybe defective IC socket.
You can use a small screwdriver and carefully scrape the PCB between the solder points connected to pins 9 and 10.
If no help, remove crystal X1 and measure its resistance. Should be infinite.