Battery replacement on 2015 Retina Macbook - now blank screen

[Lethcoeb]

OK group, a little help is needed.
We have a 2015 Retina Macbook, in which the battery was completely dead.
I used the iFixit guide to perform the replacement and then I used the low voltage post-repair procedure as part of starting it back up.
On initial startup, I received the chime, and then battery charge indicator (45%) then the screen went gray and the mouse was on the display (and working).
Then the gray screen went wonky (basically turned to static). I shut down the laptop, then restarted.
After that, I only have a blank screen. Voiceover comes on, however, while I'm sitting there.
Any suggestions? I had a little problem removing the cable because of the glue, so I'm thinking I may have broken the cable - but the display did come on.
Entirely possible I screwed up the logic board, but the laptop appears to come on (sans display).
I've removed and reattached the display cable a couple of times to no avail.
Any help is greatly appreciated!

 

[Aston441]

First I’d get an external monitor connected to see if the logic board was OK.

Then I’d try reseating the cable after examining under magnification.

Then try a new cable.

Then take it to a repair shop.

 

[Lethcoeb]

Thanks - we’re at the repair shop stage now. External monitor works, and new cable installed to no avail. Maybe they can bring it to life!

 

[volkwagen1300]

what was the outcome?

 

[Lethcoeb]

Unfortunately the new video cable did not solve the problem and I haven't yet gotten the machine to a repair shop - but its on my todo list!