About a year ago, I did a review and teardown of a Zotek ZT-702S handheld oscillocope/DMM combo device. Since then Zotek had released an updated version, the ZOYI ZT-703S. Compared to the 702S, the 703S added additional functionality: instead of a single oscilloscope channel, now it has two. The 703S also has enhanced bandwidth. Its DMM has been upgraded to 25,000 counts and it also added the function generator capability.

The general circuit board layout is largely the same compared to the 702S. It is disappointing that Zotek had decided to remove the markings on pretty much all ICs. This is likely to discourage other manufacturers from reverse engineer its product.

Here are a couple of pictures showing both sides of the PCB with the input section shielding cans removed.

And here is a close-up of the input section and the MCU.

And here are a few close-ups:

The review and teardown video can be found below: