To learn more about these type of testers check out this thread: EEVblog $20 LCR ESR Transistor checker project http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: The Radio Shop on November 10, 2015, 02:53:51 PM
Attaching a few pics of various test.
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: The Radio Shop on November 10, 2015, 02:54:45 PM
And some actual testing
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: The Radio Shop on November 10, 2015, 02:55:49 PM
And a few more. note the budged cap
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: MadBoy1979 on November 26, 2015, 05:31:57 PM
hello once I assembled this tester calibration and rejoiced in the beginning. But after a few minutes use - display unit stopped showing any signs but the backlight works and does not want to exclude - if you pull the battery connector with a metal screwdriver - shorted battery short after left back to work machine - made the same problem. Display no longer displays anything, but after I visited my friend programmer - we wanted to see whether an entry in chips - but only saw FFFF you have the opportunity to send my file to program the chip
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: The Radio Shop on November 26, 2015, 06:08:32 PM
hello once I assembled this tester calibration and rejoiced in the beginning. But after a few minutes use - display unit stopped showing any signs but the backlight works and does not want to exclude - if you pull the battery connector with a metal screwdriver - shorted battery short after left back to work machine - made the same problem. Display no longer displays anything, but after I visited my friend programmer - we wanted to see whether an entry in chips - but only saw FFFF you have the opportunity to send my file to program the chip
Sorry to hear you have this problem. Have not heard of anyone out there yet that has this model fail. I am not sure if you can rad the content of the chip. I heard that some suppliers lock the code, not sure why since it is open source and is not copy right material. I would go back and down load schematic and check voltages on board.
You can go here and find folks that know this unit in and out http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?topicseen
Download manual and schematic here. https://www.copy.com/s/t%3AwBdnTSsdB3DBEmT6%3Bp%3A%252F12864tester.pdf%3Boid%3A34
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: MadBoy1979 on November 27, 2015, 06:11:45 AM
just after the turn saw another high angle captions display - very difficult to see. The program is in chips - apparently display problem.
n turn - the unit and placed no element which measure should be displayed: No, unknown, or damaged part ?
but i see this : No, unknown, or ty!aged empty!p ?
sometimes device without element to measure itself turn off after a few seconds, but sometimes characters disappear and the display is lit backlight with led over encoder
maybe the problem is a ribbon cable to the display board
Here are the latest to which came as a conclusion. No problem in the display or the board. The problem is that the program is recorded on the chip. The contrast setting is 0 to 63. At the moment I do 35 and see great. After a known time contrast changes alone 0 and barely visible - go into setting change it with only one rotation of the encoder and immediately normalized.
just saw it need Vcc = 5 v - but i have 4.94 v
after the change of voltage stabilizer HT7550-1 - I'll see the difference
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: MadBoy1979 on January 07, 2016, 01:23:07 AM
Yesterday morning my package arrives commissioned by the first link - the approach was from ebay. In the evening I put together - procedure was the same. Not even bothered to clean flux. After inserting and calibrating - I started to use it. I do not have the same problems as before. The previous assembly kit that makes the problem - Install the new display - but displayed the same - obviously the problem is around the chip. But now I do not have time to do it now.
When measuring the resistance of 680 ohms - between 1 and 2, 1 and 3, 2 and 3 - reading is the same.
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: The Radio Shop on January 07, 2016, 05:42:35 AM
Good to hear the second one is working. While browsing the net I saw another guy had got one with a faulty display. It will be interesting to find the fault with yours.
Does sound like something faulty with the chip or connections. Let us know what you find.
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: MadBoy1979 on January 07, 2016, 02:32:22 PM
These days when I have more free time - I will replace defective chips from bad pcb to the working circuit board. If all is well - a significant problem in the board.It will remove all items, cleaning and re-soldering.
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: MadBoy1979 on January 08, 2016, 03:17:25 PM
After disassembly of the unit is running which it was installed in the box for him - took chips from defective board and mount it on the workers.
http://i.ebayimg.com/images/g/lTMAAOSwjVVVw2hm/s-l1600.jpg for 8$
The problem is not bad jsoldering - in chip itself. There were files on the network for this type of tester according to the chip and display. I will reprogram a chip and will have backup tester :)
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: The Radio Shop on January 08, 2016, 03:54:22 PM
Sounds like you nailed it down. Will be interesting to see if it will program. Wonder if it was just corrupted or if the chip itself is bad. Good job!
Title: Re: DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM
Post by: The Radio Shop on June 13, 2016, 06:58:14 AM