Spent a few hours building this Banggood (jyetech.com) oscilloscope kit, but the display failed after just a couple of minutes of use. Also, the negative analogue voltage isn't working because there's no pulse train coming out of the CPU. Otherwise the CPU appears to be working fine. All a bit of a mystery.
http://bit.ly/1RzsbiM DSO138 DIY Digital Oscilloscope Kit Electronic Learning Kit
http://bit.ly/1RzsbiM DSO138 DIY Digital Oscilloscope Kit Electronic Learning Kit
Mine worked from the word go perfectly well. Against all odds.
At my first power on the display is white blank and the Green LED is steady it does not blink at all. What could be the problem?
I hate these blue resistors, when they over heat its impossible to read its values
Reheat the smt32 chip using hot air tool
The inductors are known to be a common cause of failure.
I discovered this myself after soldering the kit.
Replacing the faulty inductor with a healthy one solved the problem
check that your 79L05 isnt a 78 because i had that they sent me 2x 78 not 1 of each! i got all my voltages except -5V and i had the 0.6v you are getting. however i had the problem with my display but i managed to get it working and i still had these issues but al lthe other voltages were ok apart from V1 V2 and the -5V not present
Bought the same unit from Banggood and mine did the same exact thing. Now that makes me wonder if they are just faulty display screens.
This oscilloscope really needs 9v.
hi is this any good YES it's ok if you buy the made unit i got it for audio job's where it show live audio wave 110 MA it's very good for the money
some tec's say it's a toy i say that a bit hard i know they are selling well
I think it's highly unlikely that you killed the LCD, it looks to me like it is just not getting any display signals, and the missing -V supply probably has something to do with it, or is a symptom of whatever's causing the malfunction.
You could try replacing the LM7905 regulator and see if that gets the -V supply working again, and maybe the transistor that's part of the -V supply circuitry as well, hope that helps.
What you want to do is buy yourself a good strong magnifying loupe and use it to give each solder-joint a good close eyeball and check that they are all good, and there are no unintentional short-circuits, or solder-bridges, or dry solder-joints, I've got to the point where I always use a good temperature controlled soldering station whenever I do any soldering now, I'm looking at buying one of these Digital Scope kits from Banggood soon, it will be going in a big analog Modular Synthesizer which I'm in the process of building.
It's that connector you soldered on upside down. As Dave Jones would tell you, , all the electrons fell out! 😄
I tried to order from banggood, loged in and hit buy it now nothing happened tried several items several times, but no response WTF I guess I will go to Ebay, same product same price and they will acknowledge my order, learned my lesson
I know it's an old post but that is a clone according to JYE. They do not use a date code and the rectangle should have a label attached. FYI