mks tft 35 stopped seeing the board

[AlexejLach]

mks tft 35 stopped seeing the board. everything was fine yesterday, but today he does not see her. I flashed the screen and checked the cable, nothing helps

[AlexejLach]

#218
obsalyut the same problem as in this branch but there is no solution please help

[onsc]

Same problem here. I think uart is broken.

[mks-viva]

Most likely, the problem lies in the serial port circuit

[onsc]

Most likely, the problem lies in the serial port circuit

Should we replace chip or wait to another firmware ? What do you think?

[mks-viva]

It is difficult for me to find out exactly where the problem lies, because I don’t have similar hardware, but you can refer to MKS TFT35 hardware.
https://github.com/makerbase-mks/MKS-TFT-Hardware/blob/master/MKS%20TFT35/MKS%20TFT35%20V1.0_003/MKS%20TFT35%20V1.0_003%20SCH.pdf

[onsc]

serial ports connected to directly stm chip. So is it possible only that pins are broken?
i connected to Arduino mega. And used multi serial. Same baudrate. And clicked some printer command buttons. Nothing shows.at Arduino side. is it good method to test stm serial? Thank you.

[mks-viva]

This is serial hardware on mks tft35
STM32 PB11 RXD connect to AUX-1 RXD
STM32 PB10 TXD-1 connect to D9(Level conversion chip) , D9 TXD connect to AUX-TXD

[onsc]

Level conversion chip

Thank you very much for your interest. I just realized that level conversion chip. What do you suggest me to check or any check method to analyze ?
Maybe problem is the conversion chip ...

[mks-viva]

D9 is : SN74LVC1T45DCKR
If firmware settings is OK. I think there is a high probability that D9 is not working properly, which leads to communication failure.

[onsc]

D9 is : SN74LVC1T45DCKR
If firmware settings is OK. I think there is a high probability that D9 is not working properly, which leads to communication failure.

Thank you mks-viva. I ll try to replace in a week. I think firmware has right configuration and OK.

[mks-viva]

OK! Good luck for you.

[mks-viva]

Hi! I will close this issues temporarily.

[onsc]

Sorry for big delay. i couldn't get that part in that form. So i couldn't tried. Thank you.