Hello there!
I got my K8055 interface board soldered yesterday but when i connect it to my computer with USB cable nothing happens at all except the power LED (LD11) turns on…
When trying to connect with the demo software that came with the kit it can’t find the card. No other LED’s turns on or starts flashing when USB cable are connected. Just nothing at all happens…
The card seems to be dead as a stone to me.
The connection procedure at page 16 in the assembly manual seems pretty straight forward but i don’t get the LD8 momentarily flashing as described there. What have i missed or what can be the problem with my card? Are there any known common problems or anything that can be causing this? Does anyone have any suggestions what i should check?
I don’t think the soldering should be a problem, I have checked carefully for soldering faults but can’t find any.
High resolution pic’s of my card.
Can anyone see something wrong so tell me please… http://surl.se/cvua
Your card looks perfect - good work! Sorry that it won’t run anyhow.
The lack of LED LD8 flashes indicates that the microcontroller IC3 is not starting to run.
If you have a digital voltmeter (DVM), please check from the pins of the IC3 that there is +5V on pin 1 and +5V on pin 20. Check also that pins 8 and 19 are connected to GND. If this is the case then you may try to measure if the crystal oscillator is running. You may measure the DC voltage on the pins 9 and 10. The voltage of those pins must be some volts between 0 and +5V (but not 0 or +5V).
After measuring with my digital volt meter i can now reply to this thread:
pin 1 and pin 20 both have 5.15V.
pin 8 and pin 19 are both connected to ground.
The DC voltage over pin 9 and 10 are 2.54V.
The USB port does not cause any problems to other devices and have never been the source of problems before. After testing with my 3 other computers (to be 100% sure) with same result, I’m sure the problem is somewhere in the card.
I would sure like to have more suggestions what to check…
Soon i will be tearing my hair off…
Nothing have been done to solve this problem today but tomorrow I will clean the board from any residue to ensure there is no problem with conductive soldering residues or something (wich I personally don’t think it should be).
For the building i used “multicore crystal 400 60/40” wich shouldn’t need cleening afterwards to work. But I did also use a small amount of “Stannol lötwasser”, but just at some points of soldering.
But this couldn’t cause me this problem? Could it be conductive and short something out? I can’t imagine that to be a possible problem, but shore I will througly clean my card tomorrow. During that process i will also check all solder joints yet again.
Good that you mentioned that you have used the"Stannol lötwasser". It contains Zinc chloride. That may be the reason to all the problems you have. Zinc chloride has made the PCB conductive and probably the crystal oscillator is not oscillating.
You have to clean (wash) the PCB, especially the crystal oscillator area on both sides of the board. Remove the crystal first.
Please try to find out how you get the conductive “Stannol lötwasser” removed from the board. Probably the PIC is OK. No need to send it back to Velleman.
After cleaning the card it works perfectly.
A wonderful feeling after pulling my hair of for a couple of days.
So it’s obvious that the use of the “lötwasser” when i soldered a few of the joints at the card is what caused the problem with my card.
Well, I have to thank you guys at Velleman for your support in this matter.
I guess the solution in this case wouldn’t even been in my top 100 list of what to check.
Thanks again I really appreciate it !
Now for the next task, make it catching times to the laptop
at the race track by two Photoelectric Sensors!