HP Elitebook 840 G1 RAM Replacement - iFixit Repair Guide
Used HP 730803-001 EliteBook 840 G1 i5-4300U 1.9GHz DDR3 Laptop Motherboard - Walmart.com
Stonetaskin 802523-601 802523-001 For Hp Elitebook 840 G1 Motherboard Upgrade I3 I5 6050a2560201-mb-a03 Uma W I7-4500u Cpu Mb - Laptop Motherboard - AliExpress
HP Elitebook 840 G1 RAM Replacement - iFixit Repair Guide
Amazon.com: HP 2018 Elitebook 840 G1 14inch HD LED-backlit anti-glare Laptop Computer, Intel Dual-Core i5-4300U up to 2.9GHz, 8GB RAM, 500GB HDD, USB 3.0, Bluetooth, Window 10 Professional (Renewed) : Electronics
Upgrading Memory RAM in HP 840 G1 EliteBook, 840 G2 or 840 G3 - YouTube