'''NO''' if the CPU/VGC is bad '''there is no video externally'''. In fact ''one of the DIY test to see if a blank display problem is GPU/VGC or logic board is to use an external monitor.''
Cables, connectors, or the display itself could cause an internal display problem. Seeing as you've replaced everything else it's narrowing down to the cables (connections) or the display.
'''Go over your video/data cable connections again.''' Many times people come here sure that they've reassembled their project correctly but on a second examination have found an improper, lose or damaged connector.
IF all the connectors are right examine the cables for tension ''(that could pull a connector lose at reassembly - do not reroute cables from original paths- if they were secured with tape or sticky pads that was done for a reason, replace them)'' or cuts/nicks. If those possibilities are removed all you're left with is a damaged display.
''If this answer is acceptable '''please remember to return and mark it accepted'''.''