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Problems with Cap Tester

PostPosted: Sat Feb 07, 2015 2:02 am
by kid347
I received my package with severely bent mangled leads on the LED 4 digit DIG 1, I don't know if this is the cause of my problem or not, but I can't get the LED zero out. It is stuck on CO, when I put a capacitor in to test the number are all over the place. I have checked R11, R13, R15, and R16. All connections are in order, can you be more specific when You say "test poles short(pin1,2and 3 short to gnd) Please advise

Re: Problems with Cap Tester

PostPosted: Sat Feb 07, 2015 7:34 pm
by jye1
Since you got 'C0' displayed the LED is likely good. Usually shorts between the test terminals (i.e. between pins 1/2/3 and pins 4/5/6 of J5) can cause the zeroing stuck at 'C0'. Please remove capacitor (if any) plugged on J5 and check. R11 open could cause the problem too. Please note that R10 should not be installed.

Can you please clarify what you mean by "the number are all over the place"? What was displayed when the meter is powered up?

It will help if you can post photos of the board (both sides).

Re: Problems with Cap Tester

PostPosted: Sat Feb 07, 2015 9:42 pm
by kid347
with my com lead from the meter attached to the gnd of the power supply while plugged into 12V power supply. I get 4.9v at all pos posts on J5. all the neg are reading 0. can you tell me what I should be reading at the posts, and also what I should be reading at R11,13,15,16. R10 is not installed. When I say the numbers are all over the place, I mean when I put a 100uf capacitor in it will read 4.4 and then just start jumping all over like 2.3 to 4.8 to 5.7 but nowhere near where it should be. I confirm with my Fluke DMM that the capacitor is good.

Re: Problems with Cap Tester

PostPosted: Sun Feb 08, 2015 12:56 am
by jye1
The voltages at the points you asked about do not have a fixed value. And we don't have number for them. But I'd like to first confirm the MCU is running.

When the meter was powered up did you get some digits ('3.010") displayed? If you got this that means the MCU is running. If you didn't have it and power supply was good then C1, C2 and Y1 should be checked first.

Re: Problems with Cap Tester

PostPosted: Sun Feb 08, 2015 1:42 am
by kid347
I am very happy to report that I have found the problem and fixed it. The Cap Tester is now working correctly, The problem was that I had R11 and R12 misplaced on the PCB I check everything with a DMM before I install but I must have missed the 3.3K for 3.3M and they are very close visually. and now it zero's out and reads the capacitors correctly. So I want to thank you for your help.