It isn't documented in the manual for that system, but 1,4  is usually a faulty battery error.  Shut down, disconnect AC power and remove the base cover.  Disconnect the battery from the system board and power up on AC only. If the flash sequence ceases, the battery needs to be replaced.

For anyone still needing a solution we found on the E5540s that if you go into BIOS > Power > USB PowerShare and toggle that option on that this issue is resolved completely.   The suggestion by @AardvarkTech does work great, but it has to be changed for each dock that the system is connected to so in a hoteling environment still caused issues.   UPDATE:  Some of our machines are still having the issue after making this change, but it did fix it for some of them.  We have just starting setting Windows to never sleep while connected to power and that resolves it completely.

We are a repair shop having the same problem today during a a screen replacement job for a Inspiron 15' 7559. Device came in not powering on, I thought it was battery flat so I just proceeded without testing to put the new screen on. After putting the new one on it I found it was still not powering on, it stuck at a black screen and LED blinking 2 amber then 7 white as described in the heading.  Therefore I put back the old screen but it was the same black screen. After some play around and switching the old & new screens, pull and putting the connector back and secure it with tape etc etc. In one of the million times I made it to boot into Windows normally, everything went fine so I put everything back with the screen on and shut down the machine. I tried to run a last test before calling the customer in, found it came back stuck at black screen again. I touched nothing at all and the machine shut down like normal, no flickering no nothing.  I followed instruction found on some other threads here to long press D then power on, it ran on a self test. So I did with the old screen on, nothing happens. Then with new screen on, I could see the screen have slight color changes this time but without any back light at all. Putting the old screen back on again, this time backlight lit up but screen was badly cracked so I couldn't see anything, and after just a hard power off, it came back to the black screen again. SOOOOOOO frustrated! After looking up the fault code, the LED blink shall point to LCD problem. However the tests result switching between the old & new screens was kinda on & off, there was no solid conclusion of whats wrong also I couldn't make another successful boot into Windows. In one of the long press D self tests the new screen has lit up and it could run thru the entire self test with different solid color screens but it just wont boot into Windows, and I could not make another self test run with backlight on. I started playing around with the LCD cable, cleaned the socket and connector with alcohol and tried again, same black screen. Then I have gently twisted the cable and putting the old screen on. It booted again! So this time I have hooked up an external monitor and did the BIOS update immediately. After the BIOS update I put on the new screen very carefully and now it boots every time now. Customer has picked up the machine and both of us are happy now ;) Conclusion: I really dont know if it was the cable or BIOS update did the magic for me but I will suggest to first update the BIOS first if you are experiencing this during a LCD repair. If nothing has been replaced and it happen suddenly. The LCD cable will lead to this therefore try pulling the bezel around the LCD, unscrew the 4 screws and take the LCD out. Carefully lift the tape and use the little 'handle' to gently slide the connector out of the socket in opposite direction of the tape, then putting it back carefully. Do not touch the connector, do not bent or pull the cable by force, it is not that fragile but it only take 1 hit to kill it if you do it improperly.   Good luck!

If your Dell laptop is showing 3 white flashes followed by 2 amber flashes, here’s what that means and what you can do: What Does This Error Mean For Older Systems? This LED pattern indicates a PCI or video card (GPU) failure. On most Inspiron laptops, the GPU is integrated into the motherboard, so this is usually a hardware issue.Before jumping to major repairs, try these steps: Power Drain Reset Disconnect the AC adapter and remove the battery (if possible). Hold the power button for 30 seconds to discharge residual power. Reconnect and try powering on. Check RAM Reseat the memory modules or try booting with one module at a time. Faulty RAM can sometimes trigger similar codes. Run Dell Diagnostics If you can get any display, press F12 at startup and select Diagnostics. If there’s no display, diagnostics won’t run, which further points to a GPU/system board issue. Next Steps – If none of the above steps worked: If your product is under warranty: You can easily reach out to Dell Tech Support right here. Just click the Get Help Now button at the bottom-right corner of the page to start a real-time chat with an expert. If out of warranty: You’ll likely need a motherboard replacement (GPU is soldered and not user-replaceable). Note: Newer Dell systems (2019 and newer) with a flash code of 2 amber, 3 white will likely have a memory failure. Please refer to your service manual on the support site to confirm the exact failure. If you suspect a memory failure, then please refer to this video to see if the symptoms align.

I had the same issue for the past 6 months and finally fixed it. The main issue is the BIOS image of the Inspiron 5675 Desktop is corrupted and it needs to be flashed again. Disconnect the power cable from the Inspiron 5675 Desktop ON A SECONDARY PC: 1. Download the latest Inspiron 5675 Desktop BIOS .RCV format from here2. Click Other Formats to see the .RCV file3. Rename the file and save it as BIOS_IMG.rcv4. Copy the file to a USB thumb drive formatted as FAT325.Insert the USB thumb drive into the CORRUPTED BIOS PC and plug in the power cable to the Inspiron 5675 Desktop6. Press and hold ctrl and esc key and click your power button and keep pressing ctrl and esc and wait a couple seconds until the Inspiron 5675 Desktop will boot7. A BIOS Recovery menu will show up. Follow the procedure to recover the BIOS Hope it works for you:)