New Zoyi multimeter+oscilloscopes - ZT-70xS, up to 50MHz/250MSps (nov 2022)

[chebo]

Open up the device, take the battery out. Wait 10 seconds, power it up with USB. Reinstall the firmware while on USB power. Shut down and add back the battery. Close up the device, and power it up.

After upgrading to version 156, the following problem appeared. What to do now?
https://youtu.be/NlBVoNhc078?si=AUQjqd4prCf1g7au
The device does not respond to any buttons.

Unfortunately, nothing worked. I pulled out the battery, connected the USB cable from the computer. The computer did not see the device. When turning on the power, the Zoyi screensaver starts blinking endlessly on the device again. I sent the message to the Zoyi's support, but I'm not sure they will reply...

[indman]

I pulled out the battery, connected the USB cable from the computer. The computer did not see the device.

Remove the battery and let the device lie in this form for 10 minutes instead of 10 seconds. Then reconnect to the USB.

[chebo]

I pulled out the battery, connected the USB cable from the computer. The computer did not see the device.

Remove the battery and let the device lie in this form for 10 minutes instead of 10 seconds. Then reconnect to the USB.

No result. The device lay on the table for a couple of hours without a battery. When connected via USB, the device is not detected and when the power is turned on, the ZOYI blinks. I think the bootloader has crashed. And without some kind of intervention in the flash memory, this cannot be done. But I do not understand anything about this... Although, perhaps, there is some special combination of buttons when turning on, which restores the default boot?...

[RAPo]

Try: battery out. Press F1+On button and then insert the USB-C power. Hopefully, the scope/DMM starts up and gives you an opportunity to flash firmware.

[chebo]

Try: battery out. Press F1+On button and then insert the USB-C power. Hopefully, the scope/DMM starts up and gives you an opportunity to flash firmware.

Yes!!! This helped! Thank you very much!!!

[Niklin]

Good afternoon. Help me identify the charge controller in the zoyi 703s. I was on charge while working with an oscilloscope. I touched the power diode of the unit I was repairing. Through the ground of the oscilloscope - the charger wire, to the ground of the network, the zoyi 703s burned out. It stopped charging. Charge controller 4086B. I can't find any description of this controller. Help me find an analogue.

[mebel]

Good afternoon. Help me identify the charge controller in the zoyi 703s. I was on charge while working with an oscilloscope. I touched the power diode of the unit I was repairing. Through the ground of the oscilloscope - the charger wire, to the ground of the network, the zoyi 703s burned out. It stopped charging. Charge controller 4086B. I can't find any description of this controller. Help me find an analogue.

https://www.alldatasheet.com/datasheet-pdf/pdf/1152028/HMSEMI/HM4086.html
HM4086B but in chinese

[Niklin]

Thank you. But it seems to me that there is a second wiring here. Tomorrow I will try to draw and identify the power pins.

[Vandeko_bass]

It seems that Zotek has already built another device, it is available on the market as Aneng AOS04 and Winapex 810B, Winapex is a sub-brand of Tooltop, probably in a while they will release a Zoyi ZT-704S, I believe that our ZT-703S must have already fallen into oblivion and we will continue to face the problems, at least this time I learned my lesson, I have the 702s and bought the 703s, I will not buy the 704.

[ajar171]

It seems that Zotek has already built another device, it is available on the market as Aneng AOS04 and Winapex 810B, Winapex is a sub-brand of Tooltop, probably in a while they will release a Zoyi ZT-704S, I believe that our ZT-703S must have already fallen into oblivion and we will continue to face the problems, at least this time I learned my lesson, I have the 702s and bought the 703s, I will not buy the 704.

I don't think, that this meter is a successor to the ZT703. It is worse in every technical spec: single channel, 10MHz bandwidth, 48MSPS, 9999 count DMM.

Also they have square wave coming out of the power outlets at Aneng... 

[xfint34]

The UI is completely different. Maybe they restart another line of models with a better base to build off.

[tunk]

The specs of the AOS04 is very similar to the ZT-702S.
That together with the different UI suggests that it's not
made by Zoyi/Zotek. Also, there a separate thread about
this DSO/DMM:
https://www.eevblog.com/forum/testgear/new-dmmdso-aneng-aos04-1ch-10mhz50msps-(march-2025)

[kalexa1955]

But it seems to me that there is a second wiring here.

No wonder. Above was wrong hint.
Your chip is MicrOne ME4086B.
https://datasheet4u.com/pdf-down/M/E/4/ME4086-Microne.pdf

[Sereg]

Tell me. has anyone managed to install the new firmware ZOYI-703S-FW-V156.ZTK?
Tell us how to do it.

[Vandeko_bass]

The specs of the AOS04 is very similar to the ZT-702S.
That together with the different UI suggests that it's not
made by Zoyi/Zotek. Also, there a separate thread about
this DSO/DMM:
https://www.eevblog.com/forum/testgear/new-dmmdso-aneng-aos04-1ch-10mhz50msps-(march-2025)

Actually your analysis makes perfect sense, it may be a new line, but I also got the feeling that it is not manufactured by Zotek, I have seen this interface on one of those cheaper devices, thanks for the link, I will read it now.

[Vandeko_bass]

Tell me. has anyone managed to install the new firmware ZOYI-703S-FW-V156.ZTK?
Tell us how to do it.

Turn on the device while holding down the F1 key, it will display information with the ZOYI logo and the words "USB: Disk Driver", just connect the USB cable and you will see a kind of flash drive on the computer, drag the .ZTK file to the firmware folder on the drive that was mounted and wait for the device to update.

[Niklin]

Yes, that's it. The wiring of the chip is the same as in the diagram. Thanks.

[ajar171]

Just a quick update:

- USB-MSC works again (after I broke it )
- logging to flash works (also saves min/max, when averaging is active)
- averaging works
- envelope (min/max) display added (can be switched off), when the averaging is switched on

Now I have to make a bootlader and a startup file, because the firmware is already bigger, than the 128k flash of the MCU... 

[RedFox01]

Just a quick update:

- USB-MSC works again (after I broke it )
- logging to flash works (also saves min/max, when averaging is active)
- averaging works
- envelope (min/max) display added (can be switched off), when the averaging is switched on

Now I have to make a bootlader and a startup file, because the firmware is already bigger, than the 128k flash of the MCU... 

Great news! Since you are already planning to write your own bootloader and firmware, you might want to consider upgrading your MCU to the STM32H743VIT6 It gives you significantly more flash (2MB vs 128kb), RAM and performance, and is probably compatible with STM32H7B0VB peripherals?

[maxmatteo]

Just a quick update:

- USB-MSC works again (after I broke it )
- logging to flash works (also saves min/max, when averaging is active)
- averaging works
- envelope (min/max) display added (can be switched off), when the averaging is switched on

Now I have to make a bootlader and a startup file, because the firmware is already bigger, than the 128k flash of the MCU... 

just great! cant wait until you have the first proper version available. let us know how we can help!

cheers from hamburg

max

[ajar171]

Great news! Since you are already planning to write your own bootloader and firmware, you might want to consider upgrading your MCU to the STM32H743VIT6 It gives you significantly more flash (2MB vs 128kb), RAM and performance, and is probably compatible with STM32H7B0VB peripherals?

Sure, that would be an option, I will probably even do it for my meter, but not everybody wants to replace a 100 pin MCU in their meter. The firmware should work on a stock v2.2 PCB as it is and I am not keen on selling upgraded ZT-703s.

Maybe Dave would like to sell EEVblog ZT-703+ meters with a powerful MCU 

Anyway, the firmware has to be split between the internal and the external flash, at startup the external flash has to be copied to RAM.
Lots of work, because Zoyi cheaped out on the MCU...

[maxmatteo]

i would offer replacing that chip if anyone needs help in the european area. its around 11€..

[ajar171]

i would offer replacing that chip if anyone needs help in the european area. its around 11€..

A properly sized MCU would sure save me a lot of work (that could be spent on additional features and not on a custom bootloader). The core of the STM32H743 is even 200MHz faster, that chip is pretty powerful.

I cannot decide this myself, please post your opinions here.

[indman]

The firmware should work on a stock v2.2 PCB as it is

That's right!

[uncle_sem]

Or restore default settings in menu.

didn't work for me