Dell Inspiron 2 Beeps and No Screen Image?

You can try clearing BIOS:

Power off and unplug

Press/hold power button for ~15 sec

Open case and remove motherboard battery

Press/hold power button for ~30 sec

Reinstall battery (right-side-up!)*

See if it boots with only mouse, monitor and keyboard connected

If clearing the BIOS does not work and as you have already reinstalled the memory modules, as detailed here:

First remove and reinstall all the memory modules and try starting the system.

Still does not start, remove all the memory modules, then install only one module in slot 1 and see if the system boots and if the computer starts normally, reinstall an additional module.

Does not boot, move the module to slot 2 and again see if the system boots, no boot, try the module in slot 3, no boot, try installing in slot 4.

Still does not boot, then remove the first module and using the second one, repeat the sequence described above.

Still no boot, try installing any remaining modules, one at a time, using the above procedure.

Continue until you have identified any faulty module [or slot] or reinstalled all modules without error.

Still does not boot, buy a new compatible memory module and try that.

Then if the computer still does not start, it's possible that the motherboard has failed and needs to be replaced.