8 Krypton

Re: No signal Dell Precision T1650

It seems CMOS has been reset in the right way.

If the machine is working you can install another graphics card on it.  I understand BIOS video setting is "auto," so your workstation should be bootable and you should be able to use it with your monitor again.  From here you should be able to reset BIOS settings (a security setting like Intel TXT will probably need a manual disable from the BIOS menu, just returning to factory settings may not affect TXT status), run the hardware diagnostics or even identify the on-board graphics as the responsible of this failure.

For testing it does not need to be a high end graphics card.  I would avoid a high end ATI/AMD or NVIDIA card as the power supply on your small workstation may not be enough to power it.