Computer not Starting gives yellow lights continuously then shutsdown

Does anything appear on the screen like the DELL logo? Are you able to get into the BIOS by pressing F2 key when you power on?

Do you mean the amber/yellow/ orange light is on continuously or blinking continuously?

Continuosly ON indicates a boot failure, including the power-supply unit.

Continuously Blinking amber indicates a boot failure but the power-supply unit is functioning correctly.

Here are more detailed Light Error Codes:

DELL G5 5000 Diagnostic light codes (Amber , White) Problem description

The first number is the amber or yellow light and indicates the number of flashes. The second light is the white and again number is how many flashes. For example 3 yellow flashes followed by 1 white flsah indicates a dead CMOS battery.

1,2       Unrecoverable SPI Flash Failure

2,1       CPU configuration or CPU failure

2,2       System board: BIOS or Read-Only Memory (ROM) failure

2,3       No memory or Random-Access Memory (RAM) detected

2,4       Memory or Random-Access Memory (RAM) failure

2,5       Invalid memory installed

2,6       System board/Chipset Error/Clock failure/Gate A20 failure/Super I/O failure/Keyboard controller failure

3,1       CMOS battery failure

3,2       PCI of Video card/chip failure

3,3       BIOS Recovery 1: BIOS recovery image not found

3,4       BIOS Recovery 2: Recovery image found but invalid

3,5       Power Rail Failure: EC ran into power sequencing failure

3,6       Paid SPI Volume Error

3,7       Management Engine (ME) error. Timeout waiting on ME to reply to HECI message.

4,2       CPU Power cable connection issue