Why does my Galaxy Grand Neo show only vertical stripes?

[AC Question]

Hello, I bought a second hand working Grand Neo with broken digitizer.
After replacing this last I only get vertical stripes on the LCD when starting up and these stripes disappear after a few seconds. If I push the power button again the stripes reappear.
I am certain I did nothing wrong, all cables were disconnected and reconnected as it must, could it be that something on the motherboard was hit by static electricity or did the LCD break down?
I cleaned the contacts of the video plug but this didn't help.
What can I check more to let this phone work normally again, as it did before the digitizer was replaced? It's a chance I tried it before closing the internal bezel.
Thanks in advance, regards,
Carlo

 

[B. Diddy]

Welcome to Android Central! Before you did the digitizer repair, did the screen actually work?

 

[Dontknow41]

Thanks for the fast answer. I couldn't reply earlier because I couldn't remember my old userid and password, so I had to reregister under another nick.
Yes, it worked perfectly before changing the digitizer.
As I did everything with great care, the only thing I can think of is static electricity.
What I would like to know is if this is caused by a defection in the screen or from the internal circuit.
Regards,
Carlo

 

[B. Diddy]

I'm not sure if there's a good way to tell, short of bringing the phone to a qualified technician to take apart and test.

 

[Dontknow41]

Thank you for your reply, I'll see what I can do to solve this problem, then I'll let you know.