MD4-10 display turning white and can't communicate

Dragos Popa 1 year ago in Master modules / MD4 updated 1 year ago 3


Our company's electric vehicle is using a MD4-10 display/controller with the IQAN software. Yesterday, the MD4-10 suddenly started to show lines of color on it and turned white. After a reboot, the screen seems to open but only showing a white screen and we are not able to communicate with it through an IQAN ethernet connexion.

We are trying to figure out what exactly happen so we do not repeat this mistake on the spare display that we have. 
I believe something similar happen in 2015 on another post and it had to do with the supply being too low. But it was mentioned that that issue was fixed. Furthermore, we supply 12V to the Display with a 2 A fuse as well as the RTC protection circuit that is suggested in the manual. 

- Our negative connexion is connected to the negative of the 12V battery through the vehicle's chassis. However, we also supply everything including another MD4-10 the same way. Could this cause this type of issue ? Does it need to be directly connected to the negative of the 12V battery?

- Can a short circuit between the power supply and the RTC input cause a fault of the screen, or just prevent the screen from being turned off?

Image 3641

Thank you for your support.


Correction: the fuse we are using is 3A.

The best way to find out what went wrong is to get the damaged module investigated, my recommendation is to reach out to the Parker distributor for this. 

As the error seems to have come at startup and the module is not responsive, I am suspecting a rare problem with flash memory, that could happen on versions prior to 6.04 / 5.08. (see Release notes - IQANdesign 6 case 52603) 

The chassis grounding you describe can be problematic for other reasons, we always recommend running wires from the module ground back to battery negative. Hence the name -BAT. But I would be surprised if it led to damaging over-voltage with the symptoms described here. 

A short between +RTC and +BAT is never damaging to the module, the reason we recommend this is to reduce the risk of having a wiring short between +RTC and +BAT bypass the emergency stop. 

Hello Gustav,

Thank you for your answer. For now, we simply replaced the module with another one and it seems to be working fine. My communication with Parker technical support came to the same recommendation: to ship back the module and have a Parker or Parker distributor team inspect it. Before replacing the module, we did some grounding tests to see if there is a difference between the chassis and the BATT- of the battery and no real difference was found which is normal since the BATT- and ground are connected. 

Thanks again.