Chosen Solution
Hi, I am a user of a Dell Latitude E7440. The last time the laptop powered on was when it was on the power cable, while I was playing Cruise Ship Tycoon on Roblox. Then, suddenly, the screen went black, the power, hard drive and charging lights all went off, the fans stopped, and it didn’t boot up ever again. I tried a lot of methods, and they don’t work. Does somebody have an idea to fix this?
Hi @zerobuss , If you know which component is the problem but can’t read its markings (burnt out etc) then here’s the schematic for the motherboard. Use the component’s board designation and find it in the schematic to find out what type of component it is and its values etc. Then search online for a replacement part using the information etc.If you don’t know which component is faulty then you will have to start at the beginning. For example, with the charger connected is the laptop indicating that power is connected? If not, then why not? Is the DC-In jack OK etc? If so, are the various power regulators OK and so on etc? You will need to know how to read schematic diagrams and also how to use a DMM (digital multimeter) to hopefully find out what’s wrong. Alternatively, contact a reputable, professional laptop repair service and ask for a quote.
Try to disconnect the CMOS battery. For some odd reason, these machines are more prone to CMOS RAM corruption then later models like the 7490. It seems like Dell has a few models where the motherboard is sensitive to the CMOS battery voltage being at 2.5-3V. It’s usually revivable by “resetting” the CMOS RAM, but you should check the voltage and replace if it’s less then 2.5V to prevent the issue from coming back. HP and Lenovo aren’t as sensitive about it. All you need to do is remove the bottom panel, disconnect the CMOS battery for a minute, restart the notebook without it and then reinstall it - the install delay is to confirm if the CMOS RAM corrupted and can be used, or if the voltage is too low. If this doesn’t work the motherboard is bad and at that point the laptop isn’t worth fixing at this point due to how old the series is.
