I assembled the kit but the display does not show data when the button is pressed twice while calibrating and all probes connected to each other. It only lights up for a few seconds and then goes out again.
Is there a way to test the display to find out whether it has been soldered correctly?
or
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Update: VR3 pin 1 should give 3V3 but I measure 4V39. Anyone had the same problem?
Is VR3 defective? Did the overvoltage blow my LCD?
Hello,
First we have answerd this topic on Your posted Customer Care Ticket. and topic above.
And today we have sended the requested parts to You by post.
When you receive the parts, first to do is replace the IC1 4050.
In the most cases this will solve the problem of no text on LCD.
Due wrong delivered batch of CD4050. Our apologies.
Best regards,
Velleman Support
Hello guys,
my feeling is, that I have the same problem.
After assembling all parts I did the first test - if fails - only the background light of the display was on.
After about 25 seconds the display got off, however turned on again by pressing the button.
Again after about 25 seconds the display got off. (see attachment)
So I checked the soldering and parts - everything ok.
Next I checked the voltage - however without LCD PCB.
The output of VR3 had 4.4V while the input was about 5V - originally it should be 3.3V
Based on information of the forum
https://forumtest.whadda.com/t/k8115-komponenten-tester-kit/33602
I removed IC1 (CD4050) - in this case the output of VR3 had 3.3V.
So I assume that I probably have also a problem with wrong or damaged CD4050.
Based on the information of this forum I opened a ticket, however they closed the issue
explaining, that I should search for help in this forum.
It seems that the Velleman product support dont’t care about customer issues.
How should I proceed now?
Any suggestions?
I reopened the ticket and requested a new IC1 and VR3. Copied the solved forum item which had the same problem. They’ve sent me a new IC1 and VR3.
I replaced de IC1 but still the same problem. I did not get to check the VR3 yet.
Hello, yes, my unit, from Riedl Electronic, Graz, Austria, seems to have the same problem.
Only Backlight, nothing displayed.
I checked everything about 200 times, could not find any assembling failure.
In the meanwhile I got CD4050 and VKVPA020.
Many thanks to the customer support.
However when replacing CD4050 - nothing changed - exact the same behaviour.
The I got back to my own CD4050 and replaced the processor (ATMEGA328P) with the new one (dsPIC33FJ32GP) the behaviour is different. When pressing the button the backlight goes on, resuming the button the backlight goes off. I have no knowledge about the controller.
Changing both CD4050 and processor with the two new items I have the same behaviour.
So it seems the replacing CD4050 makes no change in behaviour.
Replacing the processor doesn’t make it better.
The display still doesn’t work (except the backlight).
How can I check the LCD board?
What type of LCD is used - is there any datasheet?
I found in a different forum this hint
https://forumtest.whadda.com/t/edu-08-spareparts/13827
part No: ATPFF12864WP67
and another in
https://forumtest.whadda.com/t/another-lcd-display-for-audio-analysator-k8098/11970
Display used is the ATPFF12864WP67 from ArrowTech. Maybe you can find a compatible device.
However nothing else that could help me to test the LCD board.
Any ideas?
Hello Achim57 & streetman_chris,
If after replacing CD4050 and / or CPU the problem is still not solved.
Possible problem with the display. In this case it will be best to return the product to the store where purchased for RMA REQUEST.
Best regards,
Velleman Support
Calibration successful completed with a few simple tricks to go through the full cycle.
I had the same problem as many. After the second short press of the button, the screen went blank. I’ve read that it should be a hardware problem, but I think it’s an error in the sketch(program) of the timer for the second press of the button. Because if I briefly press the button after short-circuiting the 3 pins (one pin of the capacitor is used for this and I always leave pin 1* connected in the total test), the calibration cycle can start. Now comes the main trick: you have to keep pressing the button for the second time for the program to do its testing. The two problems are that the program stops when I release the button and I only have two hands (I asked my wife to help me). I quickly connected the capacitor to the 2 pins(1* and 3) about +/-2sec after it asked my to disconnecting the three pins and showed some data of it. The measurement of the capacitor went well too this way. So calibration succeeded……(after a few tries).
I’ve looked for the sketch online to modify it and then upload it to the atmel328 again, unfortunately I can’t find it but I’d like to give it a try. I have version 1.12k. The tester works perfectly now. And I must say it is a nice and good PCB and clear instructions and many extras in the menu of the tester. Now I`am verry happy with my purchase. Thanks….
Calibration successful completed with a few simple tricks to go through the full cycle.
I had the same problem as many. After the second short press of the button, the screen went blank. I’ve read that it should be a hardware problem, but I think it’s an error in the sketch(program) of the timer for the second press of the button. Because if I briefly press the button after short-circuiting the 3 pins (one pin of the capacitor is used for this and I always leave pin 1* connected in the total test), the calibration cycle can start. Now comes the main trick: you have to keep pressing the button for the second time for the program to do its testing. The two problems are that the program stops when I release the button and I only have two hands (I asked my wife to help me). I quickly connected the capacitor to the 2 pins(1* and 3) about +/-2sec after it asked my to disconnecting the three pins and showed some data of it. The measurement of the capacitor went well too this way. So calibration succeeded……(after a few tries).
I’ve looked for the sketch online to modify it and then upload it to the atmel328 again, unfortunately I can’t find it but I’d like to give it a try. I have version 1.12k. The tester works perfectly now. And I must say it is a nice and good PCB and clear instructions and many extras in the menu of the tester. Now I`am verry happy with my purchase. Thanks….