Would a dead battery cause this?

Sorry it's 5577, I tried without the battery and still just get a slow white light blink

Service tag

If it was me, I would remove the battery.

Press the power button to release flea power.

Plug in just the AC adapter and see if the laptop will boot.

What model Inspiron? There is no 577. If the battery is over 2 yrs old it's dead and needs to be removed. Try the adapter alone. If the computer is a recent model, the adapter alone should work.

Edit your post to remove the tag by clicking on the 3 dots in the upper right corner. This is a user to user public forum and personal info is not allowed. Did you remove the battery completely and try the adapter alone? 

Here's a support page that might help-- Dell Inspiron 15 (5577) Gaming Usage and Troubleshooting Guide | Dell US

I tried disconnecting the battery and just using the charger. Still no power to the power button and just one long slow white light blink

Can't edit the post 3 dots don't give me an option

It is broken. sorry,.

I replaced the battery and the laptop is still dead.

I'm assuming you press ' Power On" button for about 20 seconds before installing the new battery....

Next thing to do is reseat memory module (Ram) to see if it will make a difference.The computer has 2 SODIMM slots for ram.

Support for Inspiron 15 Gaming 5577 | Documentation | Dell US

I don't know if your computer has 1 or 2 memory in both slots. You can check by using the link below:

How to Check the System Configuration on Your Dell System | Dell UK

Check out the information in link below, hopefully it will be of help to you as well.

How to diagnose and resolve common memory issues on a Dell Notebook PC | Dell US

EDIT:

Tried resting the dimms. Its still a brick..

Unfortunate reseating ram didn't fix the problem.

Reseat coin cell battery by followings steps in link below. Please leave coin cell battery out for about one hour before replacing it back into the bay. Reseating the battery should restore BIOS to factory defaults.

Hopefully computer is up and running again. 

Note: Please view Service Manual / Removing Coin Cell thoroughly. This will require some work to get to the coin cell battery. 

How to Perform a BIOS or CMOS Reset and Clear the NVRAM on Dell Systems | Dell US

If reseating the coin cell battery doesn't fix the problem, I suspect the computer is experiencing a motherboard problem. You probably will need a motherboard replacement.

Please contact Dell Technical Support for further assistance in link below:

Contact Information | Dell US