Today marks a fresh start, and another Dell laptop needs repair. A customer came in with his Dell Latitude 5520 laptop, which had ceased functioning after a power surge caused by a low-quality, off-brand USB-C dock damaged it upon connection. Upon powering up, the laptop displays an error code of three orange and five white blinks, indicating a corrupted BIOS. Based on previous experiences, I anticipated additional issues resulting from such a power surge. An attempt to perform a CMOS reset proved futile. The only solution was to detach the BIOS chip from the motherboard, examine its contents with a HEX editor, and reprogram it with a new BIOS. This procedure resolved the BIOS error, yet the laptop refused to start.
A thorough inspection of the power rails revealed the absence of the 1.2-volt rail for the RAM. A thermal camera inspection quickly identified an excessively hot component on the motherboard's underside. After removing the motherboard for closer examination under a microscope, I discovered that the power management IC, responsible for the 3.3 and 5-volt rails, was overheating. It was imperative to replace this chip. Despite this, the 1.2-volt rail remained missing, and the MOSFET driver lacked the enable signal required for activation. It required some investigation, but I eventually located the faulty chip that failed to send the enable signal. The 1.2-volt rail was restored after this chip was replaced.
Fortunately, the laptop was successfully revived, adding another rescue to my record. If you need a repair, visit partspeople.com
