Question Dell All-In-One won't exit LCD built-in self-test

[eman2022]

I've been trying to resurrect my Mom's older Dell machine, but I have run into a display issue. This is an All-in-One Touchscreen PC she bought from Walmart.

So far, I have cleared CMOS using the jumper method. I am now able to get the DVD drive to spin, the HDD also sounds like it's spinning (light is blinking) and the Motherboard light is on. However, it never reaches the Dell Bios screen. Instead, it goes into LCD Built-in Self-Test and just stays there. An example of what it is doing is at the 1:00 min mark in this video:

View: https://www.youtube.com/watch?v=z46y1yHPO2c


It doesn't respond to any keyboard input - wired or wireless. It just flashes Red, Green, Blue and Black over and over again.

Here is the spec of this pc:
Computer: Dell Inspiron 20 All in One 3048
Processor: Intel Pentium G3220T Processor
Memory: 4GB

Any help or suggestions would be greatly appreciated.

 

[Lutfij]

Welcome to the forums, newcomer!

You could see if using a BIOS programmer on the BIOS chip for that AIO helps you out but I doubt that's going to aid you since AIO's like that tend to be discarded once they exhibit issues. Might even be a faulty motherboard.

You could see if recovering the BIOS is possible for your AIO, following this guide;
https://www.dell.com/support/kbdoc/...recover-the-bios-on-a-dell-computer-or-tablet

You will need to use the Service Tag on Dell's support site to bring up a support page, then locate the latest BIOS and see if the executable allows you to create a BIOS recovery drive.

 

[eman2022]

Lutfij,

Thanks for the response! After trying everything I know, I think this is just a bad motherboard issue. I've seen some videos where one little capacitor on the power inverter was the culprit. I also found a video where something similar happens on this exact model, but the screen just stays black. Poor soul had two of these!

One thing I forgot to mention - I got this AIO without the Dell power supply. I ordered a new generic power supply on Amazon when I got the machine: https://www.amazon.com/gp/product/B08P5PDZJ2/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

I know Dell's cables are proprietary, so perhaps it is just not getting the right voltage? If I compare the voltage on the cable with whats on the back of the AIO they should match - right?

Everything powers up fine (screen is black), however the CPU fan will briefly stall to zero RPMs after a minute or so, then cranks right back up. That is when the LCD Built-in Self-Test kicks in.

I guess I'm just trying to provide as much info a possible, in case someone else has this exact issue and is searching for clues.

Thanks and, again, any help or suggestions would be greatly appreciated!

 

[ex_bubblehead]

Considering that that power supply you listed is for Dell 3000 and 5000 series and you have an 8000 series I'd start with you not supplying the correct power. You can't go plugging power adapters in just because the plug fits. First thing is to obtain the correct adapter and then, if it still doesn't work, proceed with troubleshooting.

 

[eman2022]

ex_bubblehead,

Apologies, I put the wrong model number in the original post. I have corrected that error. It is indeed a Dell Inspiron 20 All in One 3048. I do think I bought the right power adapter. Sorry for the confusion.