|"When starting up my Dell Latitude D820 absolutely nothing happens: no cmos check - screen remains black. Can hear HDD spinning. LED's for power, HDD and battery charge light up, only power remains. "|
That sounds like it's starting up fine - you just have no video.
Do you normally hear a beep when the POST completes successfully while booting ? If you do, if you're still hearing that, your only problem may be with the video.
No video or a problem with the video on the built in display on laptops and netbooks are COMMON problems.
The computer may be working fine other than the video problem - you just can't tell that it's working fine because you're seeing nothing on the built in screen.
The led that indicates the battery is charging will not stay lit if the battery is fully charged.
The hard drive activity led will go out shortly after Windows reaches the Logon screen, if you normally have to Logon to you user in Windows.
Try connecting an external monitor to the laptop.
Laptop no video (or video problems), and battery, AC adapter, power jack T shooting.
See response 1:
DO NOT plug in or unplug a monitor's video cable into / from a video port while the computer is running. Doing so can damage the monitor's circuits and/or the video adapter's circuits.
Some laptops will display on an external monitor without you having to do anything.
If you get no video on an external monitor, some laptops have a key combo that you must press to toggle the display to external video only / built in display video only / sometimes both - see the Owner's or User's manual for the model (e.g. press both Fn and Fx ; x is a number).
If that doesn't help....
Have you, or is it possible someone else who had access to this computer...
- dropped it, or dropped anything on it, or otherwise exposed it to a physical jolt ?
- spilled liquid on it, or sprayed it with liquid, or exposed it to liquid such as rain ?
Since the video last worked properly all the time, has there been a power failure event that happened while the AC adapter was plugged in ?
Those things are the most frequent reasons something inside the laptop has been damaged.
Dell™ Latitude™ D820 User's Guide
User's Guide - Troubleshooting
There's nothing in there about your status led symptoms indicating errors, other than a discharged main battery.
Your computer may produce the same status led symptoms when you hold down only the Fn key while booting when there's nothing wrong with it. Usually if not always, you press a combo of keys - e.g. hold down Fn and then press another key, let go of both keys.
Manuals (all of them)
Dell™ Latitude™ D820
The Service manual shows that the video adapter for your computer is built into the mboard and cannot be removed.
If you get no video on an external monitor, the mboard, or some other essential component that plugs into it, must be replaced
The Cmos battery has nothing to do with a video problem on a laptop (or on any compute, for that matter, unless the main chipset supports hybrid video on a desktop mboard).
Incompatible ram can cause no video and no boot, no beep codes if that applies, but if the ram installed in the mboard is the SAME ram it had in it when the video last worked fine on the built in display, the video should work on at least an external monitor even if the Cmos battery is too weak, or dead, or is installed d so it's polarity is backwards, if that's possible )if it's a button cell you must see the + on top of it when it's been installed), or if the Cmos battery is not installed at all.