XPS 8700 Will no longer start - SOLVED

My computer failed to POST (Power on self test) and after weeks of physical checking, disconnecting everything, numerous web site searching and IT expert advice, I was told either power supply or Motherboard is dead. I bought a new computer. Months later I decided to try again and this time on power up, I got 3/4 beeps. Finally I was able to check the error code saying RAM issue.

Because of the age of the computer I thought the RAM cards where well seated but after pulling them out and in, I finally gave that last hard push and got a solid click.

After that the computer started as if nothing ever happened!

So still today in June 2024,  my XPS 8700 with GTX 1660 super and original 480W power supply works perfectly. Sad part I bought a new AMD computer (R7 7700/RX 7800XT) and this has more issues than this one with video editing.

Hence never give up until you find the root cause.