Major Upgrade led to MacBook booting to flashing screen
i just ordered a ton of upgrades for my old Mac Book Pro (Mid 2010) and followed each of the guides. I started with the easiest the battery and it worked perfect after replacing the old. Then moved on to the speakers which actually was when the problem arose. After putting in both the left, right and sub-woofer when I went to turn on my mac book the fan and everything sounded on including a chime at first but then the screen just flashed.
MacBook Pro 13" Unibody Mid 2010 Left Speaker Replacement - left speaker purchased and installed just as stated in the guide
As well as the right speaker - MacBook Pro 13" Unibody Mid 2010 Subwoofer & Right Speaker Replacement
I went back and tried to check all the cables everything seemed to be in order, except the camera cable seemed to be a bit bent but I don't think that would cause the display to malfunction.
I thought i could just finish with the upgrades [RAM and hard drive] then maybe be able to boot up and install OS easily. Not the case however, the screen still just flashes continuously.
I tried to see if it worked with an external display but nothing would even connect. Should I try to put the old hard drive and ram back in to test the external display?
Did I just ruin the chance of upgrading my Mac Book?
So I went back and put the original left speaker back because I noticed the new speaker did not have the same gap to fit properly over a chip. I also put the original hard drive and RAM back. The MacBook now boots but display flashed and doesn't work; however, I have an external display hooked up and it works with the TV.
Is the problem possibly faulty NVIDIA or the Logic Board or possibly the display?
What can I test?
I may swap the logic board with my brothers old mac book also a 13 inch unibody from 2010.