[SOLVED] Installation of new Samsung 850 Pro 512 SSD onto MacBook lab top not booting

Strange they work fine in any browser I try.

From linked articles. Omitted or modified sections focused on your needs.

Start up from macOS Recovery
macOS Recovery installs different versions of macOS depending on the key combination you press while starting up. Hold down one of these combinations immediately after pressing the power button to turn on your Mac. Release when you see the Apple logo or a spinning globe.
Command-R
Reinstall the latest macOS that was installed on your Mac, without upgrading to a later version.1
Option-Command-R
Upgrade to the latest macOS that is compatible with your Mac.2
Shift-Option-Command-R
Requires macOS Sierra 10.12.4 or later Reinstall the macOS that came with your Mac, or the version closest to it that is still available.
1. If you're selling or giving away a Mac that is using OS X El Capitan or earlier, use Option-Command-R to make sure that the installation isn't associated with your Apple ID.
2. If you haven't already installed macOS Sierra 10.12.4 or later, Option-Command-R reinstalls the macOS that came with your Mac, or the version closest to it that is still available.

Erase your startup disk
Erasing your startup disk permanently deletes all of the data stored on it.
1. Select Disk Utility from the utilities window of macOS Recovery, then click Continue.
2. Select your startup disk in the sidebar of Disk Utility.
3. Select the disk name, not the volume name indented beneath it.
4. Click the Erase button or tab.
5. If you don't see an erase button or tab, select the volume name indented beneath the disk name, then look again.
6. Complete these fields:
- Name: Enter a name for your disk, such as "Macintosh HD".
- Format: Choose Mac OS Extended (Journaled).
- Scheme (if available): Choose GUID Partition Map.
- Click Erase to begin erasing your disk.
7. When done, quit Disk Utility to return to the utilities window. You're now ready to reinstall macOS.

Choose reinstall macOS then Continue

Use Migration Assistant
1. Open Migration Assistant, which is in the Utilities folder of your Applications folder.
2. Click Continue.
3. When asked how you want to transfer your information, select the option to transfer from a Mac, Time Machine backup, or startup disk.
4. Click Continue.