K8061 CPU Fail USB Works


I recently bought the K8061 extended interface board, I have soldered it all together and got it work with my PC problem is when I run either the diagnostic tool or the demo tool included on the CD the both say the cpu failed. I read another post [url]K8061 problem] on this forum that said it might be to do with the voltage but as it said in this other post I checked the voltage from the regulator and from the pins on ic6 (11 and 32) and they all where at 5v.

I have checked a load of solder points and redone a load to make sure and that all seems fine, I went around the board with my multimeter checking the connections as well and all seemed fine.

Can anyone give me some advice on what I need to check next, or is there anyway to check if it is the chip that is not working or something along that line.


Is the RUN LED (LD12) lit when you connect the power adaptor to SK2.

Does the RX/TX LED (LD11) light when the USB cable is connected (and the power adaptor to SK2). If not - check the optocouplers IC1 and IC2 placement.

Hi thanks for your reply

Neither of the LED’s (11 or 12) come on with the power of the the usb and power.

When you say swap the optocouplers. I have switched them (put the one that was in ic1 in ic2 and visa versa, still neither of the LEDs come on). Do you mean rotate them in the socket, i didn’t want to do that without checking thats what you mean as I know that some chips can blow out if you do that (I don’t know a great deal about electronics so correct me if i am wrong)?


It seems that the microcontroller IC6 is not running.

About IC1 and IC2:
Just ensure that the notch (or small dot ) on the ICs is oriented properly as shown in the lay-out drawing.

The optocouplers have the dots pointing away from each other, I believe that is the correct orientation, please correct me if im wrong.

If it is as you say and that IC6 is not running what can i do to make it run or is it a case of the chip itself having faulty firmware or being corupt in some way and if so is there any way that you know that i can get a replacement chip or even just test to see if it faulty or might it be something else on the board?

Thanks again

The optocouplers are in right position.

Have you checked the +5V at pins 1, 11 and 32 of the IC6.

Yup I have checked the voltage at those pins and they come out a 5V, i had seen that on another forum and attempted that first and there both at 5V.

I have also checked the voltage into and out of the voltage regulator and it goes in as 12V and comes out as 5V

any more help you can give me is much appreciated


For some reason the microcontroller doesn’t start to run.
You may measure the voltages of the crystal X2 pins to GND. Should be something in between 1V and 4V.

Hi Again

Sorry it took me so long to reply i have been way on holiday the last week

I have just measured the voltage between X2 and the gnd, one pin came out at 1.97V and the other at 2.39V

Thanks Again

The voltages on the crystal pins are OK.

Is there anything else I need to check or do you think it is a case of the cpu is just not working?

If that is the case do you know if velleman will let me return it or can I get just the cpu chip on there own?

Thanks again

You can send me the ‘defective’ contoller directly by post:
Please included verry clear your address !

Velleman Components NV
attn. Pascal De Petter
Legen Heirweg 33
9890 Gavere.

I will send you a new, tested one back by post.

Thanks for this

How much of the kit do i need to send back, do you want all the wires and cd and usb cable as well as the board or will the board on its own be sufficient.

Thanks Again

NO !!! Only the controller’s VK8061 USB/CPU.
you can also send the complete kit for repair, but then you must send back the unit via your Velleman dealer.

Sorry I am not a hundred percent sure what you mean, do you only want the cpu (pic chip) from the board?

Thanks Again

Yes, if you think that one of these is defective, otherwise send the complete kit via your dealer, not directly to us.