MD4 crash during blue screen

Dragos Popa 2 years ago in Master modules / MD4 updated 2 years ago 4


We're using a MD4 display with IQAN Design 6.06 and during one of our session of sending the project over to our MD4 (meaning a blue screen was displayed) the module lost power and shut down. After rebooting it, the MD4 display did not reopen and even if we power it separately with an external power supply the module still does not power on. 

Do you know what we could do ? Or what the problem might be? 

What normally happens if you cut power to the MD4 while updating is that you end up with only firmware and no application. 

There are two system messages you could expect: 

Either one that says No application (the "normal" case if the interrupted update was only for the application), or one that says Erroneous application (the "normal" case if an update including a new firmware was interrupted)

In both cases, you just connect to the system and attempt the update again. 

From the description, I get the impression the MD4 is not showing any signs of life? No logo, no backlight and not possible to connect?

To me that sounds as if there is physical damage, that maybe the event caused it to loose power was something more than just simply cutting the supply.. Any chance you could have had an over-voltage?

Hi Gustav,

Thanks for the answer. Yeah, as you guessed, the display doesn't open at all anymore. We found something in the documentation that might have caused this and I wanted to confirm it with you. There is a 1.5K load that should be present on the RTC wire of the harness. However, we did not have said load installed. So, is it possible that it's this lack of protection that caused the issue ? (see image below).
Also, our vehicle was submitted to a quite drastic change in temperature a few months ago for certification, from +52C to -40C and only recently did we power it back on. Is it possible that the drastic change of temperature has affected the module?

Thank you,

The purpose of the resistor for RTC supply is to limit the current below well below the level that can power an MD4, in the unlikely event you have a wiring short from +RTC to the MD4 +BAT connection.

The temperatures you describe are also within specification. 

Since the vehicle had been off for a long period prior to this, maybe the vehicle battery was depleted? If so, it could be interesting for you to check if some form of starter aid was used. Maybe there was a mistake made during that connection. 

Hi Gustav,

Thanks for the update. Regarding the vehicle battery, it was not depleted since we have a second MD4 display module that worked perfectly well. Also, our batteries were charged before hand to at least 30%. 

If we did have a wiring short from the RTC to the BAT without the 1.5K load, can it cause what we've experience?