Joshua Humbert the 3rd and 4th lights on signifies that Memory modules are detected, but a memory failure has occurred. Suggested resolutions:
• If two or more memory modules are installed, remove the modules (see "Removing a Memory Module" in your User’s Guide), then reinstall one module (see "Installing a Memory Module" in your User’s Guide) and
restart the computer. If the computer starts normally, continue to install additional memory modules (one at a time) until you have identified a faulty module or reinstalled all modules without error.
• If available, install working memory of the same type into your computer (see "Memory" in your User’s Guide).
Check on here for an explanation of the POST codes. Your model is not listed but the same codes apply.