graphics is very low and not very bright

Hi,

First try connecting an external monitor to the laptop, just to check whether it is a GPU or driver problem.

(A TV can be an external monitor as long as it has HDMI inputs and you have a HDMI cable with the appropriate plugs to connect between the laptop and the TV)

If the external monitor’s display is OK then you either have a backlight power supply problem on the motherboard, a faulty LVDS cable (or cable connection at either end) between the motherboard and the LCD screen or a faulty LCD screen backlight circuit (which means a faulty LCD screen as it cannot be repaired it has to be replaced).

Here’s a link to the service manual for the laptop.

Scroll to p.26 to view the necessary pre-requisite steps and then the procedure to remove the display assembly.

This will also allow you to check the LVDS cable connections and inspect it for any damage.

Unfortunately there are no schematic diagrams of the motherboard online (or none that I can find anyway - you may have better luck) which would help to test if the motherboard’s backlight power circuit is OK or not.

You may have to purchase a compatible LCD screen (search online for Dell Latitude 3450 LCD screen - or look on the back of the LCD panel as usually the part number is stamped on it and search for the part number instead) to determine if the fault is in the screen or elsewhere as described above. Check the seller’s returns policy if you decide to try this option and it turns out that the problem is not the LCD screen.

If this seems too daunting, contact a reputable, professional laptop repair service and ask for a quote to repair the laptop.