My old laptop charging cable is broken. I believe the problem is in the thin wire that goes from the transformer block to the laptop plug, and specifically right as the cable exits the transformer block.

I ordered a replacement, but unfortunately it has the wrong plug.

My idea is to cut the thin wire in both cables, and joint the old, correct head to the new, functioning transformer block.

I have done this jointing on AUX cables, is it gonna be the same? I don't have a soldering iron, I hope I can just twist the copper together and seal it with electrical tape. Will this work?

The two power blocks have the same input and output voltage, but the new charger is rated 45W (2.37A at 19V) while the old charger was 40W (2.1A at 19V). I don't think that's a big enough difference to be a problem, but what is your opinion?

Thank you.