After new RAM installed I have these black lines / bands on LCD

[Lamborghini]

After I installed new RAM into my 2013 21.5 iMac the LCD started displaying these black bands on the screen. The RAM installation procedure is very difficult because I basically have to take the entire iMac apart. I double checked all the connectors and everything is plugged in. Did I break the LCD while putting the RAM in? Is there something, I should double check? I checked the 2 ribbon LCD monitor cable and they seemed to be plugged in. What am I doing wrong? Please help.

 

[nambuccaheadsau]

You are braver than I cracking open and doing that hard, hard memory increase which was not designed to be user or even technician serviceable. Go to ifixit.com and see if they have a breakdown of hard drive or logic board replacement. The gold LVDS contacts are very easily bent or broken out of shape and are the usual suspects for your problem.

This what the various contacts are like:


https://www.aliexpress.com/w/wholesale-for-imac-lcd-cable.html

 

[RyanXM]

That looks like a cracked LCD to me. I would make sure to reset any connectors that you can without removing any internals. Also, if you have an external display, check to make sure video displays correct externally.