Tachus Needs Help

[shreifali]

Hi again
just to let you remember , my board is tachus 3 axis board.
I checked the board and found that electrolytic capacitors were installed backward. I substituted them and did the test.
I will list here my troubleshooting results and tell me what is my problem:

1-With no power on , I got 4.40 Kohm between Ground and 5V

2-power on , with no ICs installed , I got 5v from voltage regulator and 5v at each IC power pin(test was done IC after another).the same after installing the ICs.

3-power on and ICs installed , probing the ICs gives the following results:

IC1 74HC14 :
pins 1,3,5,9,11,13,14 Hi (Led Bright)
pins 2,4,6,7,8,10,12 Low(Led Off)

IC3 ,IC4 (CD4030)
pins 1,3,4,6,11,12,14 Hi
Others Low

IC6(CD4030)
pins 1,3,5,6,11,12,14 Hi
Others Low

IC5,IC8 (Cd4013)
pins 1,5,9,12,14 HI
Others Low

IC7(CD4013)
pins 1,9,13,14 HI
Others Low

(Note : why IC7 readings are different from IC5 and IC8. the same for IC6 and IC3,IC4)



So please tell me what is the problem , the motors turn as a pendulum , right and left , an sometimes whizz and don't turn .

[Doug]

Hi there,

have you checked the circuit board for any shorts or solder bridges? preferebly with a magnifying glass and a multimeter,

I know it seems an obvious starting point but Ive recently built the same board and this is an area I had problems with.

one other thing to do is check to make sure ic7 is the correct way round.

regards

Doug.

[shreifali]

Hi
I made all the checks and they were all OK , but I have noticed something
I was looking at the PCB's , and I found that the PCB in the OS3Unipolardata.pdf , it was different from it in OS3copper.pdf , so I wanted to ask you which one is the right one.
The difference is where R27,R28,and the probe are installed.
in OS3Unipolardata.pdf they are connected to C8 , but in OS3coppper they aren't.?!?!?!?

might it be the problem ?

[shreifali]

I solved my problem but I don't know how , I just brushed the pcb with a shaving brush and soldered two copper places although I tested them with ohmometer and they were ok.
anyway , thx for your help especially for u phil , the board works great , i tried it with foamworks , and now I will go to implement the mechanics for a router.
thx

[Doug]

Thats great news, best of luck with the rest of your project

Doug.

[shreifali]

Thx Doug