Blank white screen, but printer working otherwise

qthurtle

Hi I have had an A3S for a couple of years - brilliant - unmodified, as it came out of the box!.

Today, I have a blank white screen. 

When I switch on, I get a beep and see "BOOTING..." in colour on a black screen. Then I get a blank white screen and no JGAurora logo, or anything else. Strangely, the touch screen is working and the printer can be controlled, by guessing whereabouts to press, etc. The printer homes, etc.

I have opened it up, checked the plugs, etc. Powered down, waited, etc. With the printer switched off, when I connect the top USB port (the square one) to my PC, I get the same "BOOTING..." and then a blank white screen.

Any ideas? I'm guessing that it is a LCD Board problem. If so, I will remove it and see if I can detect any issues (dry joints, etc).

Any thoughts would be appreciated.

Samuel Pinches

Welcome @qthurtle ,

It does sound like a MKS module LCD panel failure. I don't really have any idea what would cause that though!

Maybe try flashing the LCD firmware? (details on the wiki)

qthurtle

Many thanks for the comment. Bizarre that the word BOOTING appears perfectly which suggests that the basic driving of the screen is fine! I will delve deeper and report back.

qthurtle

Hi
I have flashed the LCD with the original firmware - no difference - blank screen.
I have flashed the LCD with the community 3.03 firmware - no difference - blank screen.
I have flashed the main board with the community firmware - no difference - blank screen.

I have removed the LCD board completely, (adjusted the input voltage from 5V to 12V) powered it from 12V - no other connections - blank screen.

Question:
Should the 'naked' LCD, powered from a separate 12V supply show a set of icons, even with no connection to the main board? I think the answer is yes - if so, then it is my LCD board which is shot and I will get a new one.

PS - so many thanks go to the community. The instructions for flashing the boards are brilliant - not a hiccup at all. So much effort has gone in to them to make such a complex thing so simple!

qthurtle

Question answered. The LCD board should show the icons when it powers up, whether or not it is connected to the main board. See this video.

I'm off to order a new one.

qthurtle

All working now. Had to buy a MKS TFT28 V4.0 board which does not fit properly into the printer without a  modification. The community firmware V3.03 seems to work fine with the V4.0 board.

Full step-through details of what I did are in this Instructable. The end result seems to be better than the original - the screen looks very neat and I now actually touch the screen (ie not through the plastic window).Now to test everything!