Did you clear BIOS after removing the old battery by pressing/holding power button for ~30 sec before installing the fresh battery? Is putting the 4th module in one specific slot causing the problem? Or is it one specific module being installed as #4 in any slot? Have you tried gently wiping the gold connectors on each RAM module with a lint-free cloth? And have you tried blowing out all 4 slots with canned air?  After you clean the modules and slots, reinstall all 4 modules. Then remove motherboard battery and press/hold power button for ~30 sec. Reinstall battery and reboot... NOTE: Unless the 4 modules are exactly identical, make sure you're pairing them correctly. One matched pair should be in 1st and 3rd slots from CPU (matching color retention clips) and the other pair should go in 2nd and 4th slots from CPU.
I have 4-slot memory, one slot won't allow computer to boot. I swap the memory stick and change slots. Ran memory test and diagnostic all test Passed. I reinstalled win 10 when a error in memory blue screen would appear days later. The computer starts up with 3-slot when I try all 4- slots the start bottom turns orange like standby color and won't start.  Please help thanks.
Memory Stick Problem