8061 run light flashing

Kits PC Related Projects
1

Hello,

I seem to be having a problem with my K8061 kit. Just yesterday, it was connected to my computer and measuring analog values with no problem. Today, however, the run light is flashing when I plug in 12VDC power. The Power LED will go on if I plug in the USB, but there is no connection to the computer.

I have tried the following things, based on looking at other threads on similar topics:
J2 voltage = 5V
pins 1, 11, and 32 of IC6 = 5V
X1 pins oscillating at 16Mkz (as measured with 10x oscilloscope probe); both read 2.2V DC

I’ve removed and reseated all the chips on the board, and have gone over nearly all the solder points. What else can I try?

2

Does the USB LED (LD9) light up?

3

LD9 does not light.

4

This indicates there is no USB connection.
The problem may be in the USB connection (cable / connectors) or IC3 or the components attached to it.

5

Thanks!

After a fair amount of tracking down, it seems that one of the resistors connected to the USB port had a foil pad that had come up. Resoldered, and back in business.