Teardown of a Micsig STO1004 Smart Tablet Oscilloscope
Review video, if you havent done so and by the way in that video youll, probably noticed that the display appeared to be a little bit blurry now that actually was not a problem of the display. I think it is unfortunately a side effect of the matte screen protector used here. The display actually looked quite good in person anyway, in this video I will open it up and take a closer look inside now. I have to say that this scope is not the easiest to disassemble. The rubber holster is very well integrated and the fit was very, very tight, and it took me quite a bit of time to actually just figure out how to remove this piece. Let me turn it over just to show you if you look at the back, you will see that you only have access to this one screw with the holster on and it is crucial to loosen this screw first, so you can pry open the bottom section of The holster and work your way all the way around anyway. It took me quite a bit to get it off in one piece: well, have to see how easy it is to put it back together since the st01004 is based on tablet computer. I fully expect to see commonality between this unit and a typical tablet, computer, with the exception, of course, of the front end of these channels, and perhaps some dedicated fpga circuit for this scope.
Now, with all these screws accessible, we should be able to open it up. Foreign is removed. You can see how nicely everything is put together. All the sensitive circuitry are under this metal shielding. So we will have to remove those, of course, to see whats going on underneath and before I open it up further. I just want to show you the screws used to secure the back cover here, and you can see that these are machine screws. They fit nicely into these metal threads. Removing the main board takes on patients, as there are quite a few flat Flags ribbon. Cables need to be removable forward, board could be taken out and you can see that I also removed this module board as without removing it. I could not release the touchscreen cable, which was routed in from underneath. I also removed the shielding cam from Channel 1, so we can take a closer look at the input section later on now. I expect all four channels are virtually identical, so I only removed this one anyway, as you can see that the board is very well laid out and the design is very clean throughout the board. There are many local power supply sections, as you can clearly see via these inductors and the power chip here appear to be a d9d320 block converter, and you actually have quite a few of these chips all over the place now, because the system is Android based, I Suspect that a significant portion of the circuit is in common with a tablet computer and you can largely infer that from the bottom portion of the circuit board here towards the right here.
You can see this chip sitting under the heat sink. I assume that is the main processor. You can also see a SRAM chip towards the left and a flash chip towards the right here. We also have a battery for the onboard real time clock underneath here we have and by the look of it icn6211 DSi video processor chip, which makes sense, as it is sitting right next to the flat Flex connector to the LCD towards the middle section. Here you can see this is where we started seeing some of the oscilloscope specific circuitry. Here we have an h80 1511, which is a 8 bit 30 to 1 gig samples per second a to d converter, and that is shared across all the four channels. Next to it, we have an ADF 4360, which is an integrated, synthesizer and vco. What is interesting is mixex use of a Soc module here. What I think is happening is that they actually put the oscilloscope specific fpga and Associated circuitry on this separate board. If that is the case, its actually very clever, as it can utilize the main tablet, motherboard design and evolving, the oscilloscope side of the circuitry is somewhat independently here on the sport, you can see we have some flash memory chip and we also have this memory controller Right here and this of course large one – I assume, is the fpj sitting under that heatsink, oh and I forgot to mention. If you look carefully here, you can see that, on top of this board, we have a uart by the look of it Port.
That, presumably, is used to test the board in production. Now here is a closer look at the bottom side of the board. We can see a lot of bypass capacitors towards the bottom right. You will see that we also have a section that is not populated. Now, if you look at it here carefully, you will see this is probably another LCD connector here. So I assume that in production runs, they may have different models of the LCD and depends on which one they use. They may choose to populate this section, or this section now before we move on to the input section. Lets just take a look at the rest of the board here on this side. You can see we have a lot of these DC DC converters as mentioned earlier, and if I move up here, you will notice that we do have a couple sections that are unpopulated. The first area, you notice that we are missing some components. Is this section right here and here we have by the look of it a few ICS and some passives, so not entirely sure what exactly of that circuitry is supposed to do. The second area that is missing components is right here now. If you look carefully, we do have a trace here by the look of it is an antenna, so perhaps they were designing some kind of RF components here, but not entirely sure. As you will see, I will show you just in a little bit that there actually is a Wi Fi chip on the other side of the board and heres another look of the cable connecting the BNC panel to the main board.
That, I believe, is for the UPI interface now on to the input section. The larger chip here is an Opa 4872, a 12 volts 500 megahertz op amp with a 421 High Speed Max and besides that, theres actually not a whole lot going on on this input. Section here now there is no adjustable components in the input section either. Now let me flip the board over and take a look at the bottom here. I dont think theres a lot going on, but I just want to point out a few things here and there, and here is the back side of the channel one input. You can see that we also dont have a lot of things going on here. All these are just some discrete components and towards the left of the channel one. We have this ap6181, that is the Wi Fi module. The shooting has used here are actually two pieces, one is from the top. One is from the bottom you can see. That here is the one that we took off earlier from channel one, and this design is actually very good. Otherwise we wouldnt be able to taken them off if they were soldered. On now, move on to the other side you can see here is actually the back side of that unpopulated footprint. On the other side, I suspect it was some kind of wireless communication module and, by the way, these pads here are not your test points.
These are actually the board Port connectors used to connect to the input section via some Pogo pins pressed against them, which Ill show you a little bit later and thats pretty much all. There is on the reverse side of this board and lets just uh. Take a look at all these bypass capacitors on the reverse side of the processor. Now move on to the front panel you can see here is the ribbon table for the LCD, and here is the touch panel controller. And if you take a look here, we actually have a by the look of it a i Square C control and lets move on here towards the bottom. Here we have two of these speakers and here is our main controller board for the input section. Let me just zoom in a little bit, so you can see the board to board connector that I mentioned earlier. You can see these are the spring loaded pins that is pressed against the pads on the main board. The main controller on this input board is an stm32 compatible microprocessor, as you can see here, and it will have a few 595 shift registers here and that pretty much wrapped up this tear down video. I am quite impressed with the design and the build quality of this mixer. St01004 is definitely impeccable, certainly heads up to the design engineers. Anyway, I hope you enjoyed the video and learned something new.