View Full Version : Problem 5 V led remain in on

12-26-2012, 10:37 AM
:withstupiHi, I have a controller with TB6560 bought on ebay. I noticed that, when the computer is turned on, and the power 24 Vdc adapter is disconnected from the board, 5 Volt LED remains 50% on. This turns off only if I unplug the parallel cable. In your opinion is this normal?
Thanks and sorry for my bad english :cheers:

12-26-2012, 10:03 PM

12-27-2012, 05:37 AM
neilw20 thanks so much for the clarification. I thought it was a dangerous interference power.:cheers:

12-27-2012, 07:24 AM
Just backfeed from the PC signals pushing up the 5v supply via internal parasitic diodes in the ICs in the breakout board.
Something to tell the PC is still ON.

12-27-2012, 12:45 PM
Yes, this happens if the computer is on. With power supply disconnected from the controller.