Strange conflict with MKS TFT and RAMPS 1.4 USB

Hi!
I'm not pretty sure whose issue it is, RAMPS or MKS TFT, but my MKS TFT can communicate with AUX1 on RAMPS only then RAMPS is connected to PC host via USB. It stops to communicate with RAMPS after I unplug USB or push disconnect button in host software.

This strange behavior appeared after I re-flashed MKS TFT to V2.0.0 and RAMPS to RC8.
MKS TFT is 1.2 version.

Would be glad to have an advise with direction to dig in.

Thank you

thats very odd... I presume you are running external power to the MKS TFT ?

I would guess TFT firmware issue, perhaps its trying to be smart and guess the baud rate and ramps just isnt saying anything till its talked to..

himm logs say "3.Deleted Baud Rate 'connect' button,but available to set it on config."

There is now a new setting in the config
#baud rate setting(1:9600;2:57600;3:115200;4:250000)
>cfg_baud_rate:4

did you set that to your baud rate?

Edited 1 time(s). Last edit at 05/26/2017 08:42AM by Dust.

Thank you for reply,

Quote
Dust
I presume you are running external power to the MKS TFT ?

Yes. MKS TFT is powered directly from 12V power supply.

Something with a ground loop?

Quote
Dust
There is now a new setting in the config
#baud rate setting(1:9600;2:57600;3:115200;4:250000)
>cfg_baud_rate:4

did you set that to your baud rate?

Yes, I did. Same as RAMPS settings value - 250000. Checked it twice.

Hi Grigory,

Exactly the same is happening to me, RAMPS and TFT only communicates with USB connected...

I tried two different screens and to different MEGA/RAMPS sets and nothing... I can't get those connected...

Could you fix the issue? In case you did, what did you do?

This is really driving me mad, it should be very simple to get TFT and RAMPS connected according to many other forums I've checked...