I have to do a bit of complaining for this product. I must say that this product has one big flaw to be sold as kit.
I've got my set, soldered first side, checked voltage according to manual, soldered another side, powered it on and what?
On LCD everything looked ok. Booted, all controls responded properly, frequency measurement worked perfectly. But signal was in form of flat line across upper half of the screen. Nothing was able to move it.
If it would be nice kit I would have documentation! Poor printout of schematic and layout is not enough. There should be a description and some reading in addition to that C14 reversed. Something like "assemble voltage converter to power opamps, check voltage on test point this and that, it should be whatever, solder another few elements, check something else"... Soldering everything on kit and powering up is a recipe for disaster. And for some people 30 bucks for couple hours of soldering is too much to just burn it!
That happened in my case. Some bad element in power converter was probably wrong. Maybe opamp. Obviously I have no idea what it could be now after all chips seem to be burned. Test points for power to opamps? 12V DC? maybe +/- 12V? Who knows? My knowledge is not as good to just look at schematic and know what voltage would be where and what exactly is happening. But I don't this kit is only for people that do know.
When I powered the unit and started to look what can be wrong it was not giving correct signal out of TL084. Some voltage was present, but not 500hz waveform that was coming in (my multimeter has frequency measurement). Another half of TL084 used in conjunction with AtMega to vary voltage out of it was probably also damaged. After couple plays with buttons my flat line is gone. ADC was getting 6-7+ V in. Probably adjusted too much out of TL084 and it burned.
What I have now? Working AtMega and lcd with menu. Almost zero chance to find bad elements to fix it in this smd nightmare with this kind of poor documentation.
Yes. Documentation is key to make from pile of parts and PCB a good kit worth your money. You sell kits so people can learn from them not only to solder some SMD resistors but how everything works. They should have chance to avoid disaster before it happens. If you're able to design this kind of equipment you could spare couple additional hours to write about it.
Why you're putting test points for something when there is zero information what should be on them? You don't solder kits by "solder everything on one side and check power". What next? Maybe there is no smoke when you power it on? You should assemble it with documentation in logical blocks, check proper operation for each one so one fault would not take down everything after it.
Scope is nice. For that price point is great event not workink
But manufacturer should spend some time to make proper documentation for that, so people can have more chances to have working device. Charge few bucks more for that paper, I don't mind. It will be worth it.
What should I do next? Order bunch of parts from digikey or mouser, spend money for parts, shipping and try to fix it? Burn some more experimenting? Order another kit and try from scratch? Order it assembled? I don't know (I'm looking forward to your advise).
I know that it was first kit I've made that I don't like just because of that documentation.
Btw. Sorry for my English. I'm still trying to learn it.