UPDATE! Just received used parts from eBay: All parts were dusted and scratched up, especially the GPU card. The I/O cable had the same type of fraying as my old cable, but slightly better. Also, incredibly banged up, as the person that harvested the part also had issues removing it from the case. Installed the front I/O and the computer loaded up without any problems. Restarted the computer and it worked the way it should. Now with the GPU card, there was a minor snag, but unlike my initial experience, there was activity. The system loaded up, without any 1-2-3 Errors (two beeps) and didn't cause the issue with double power cycling into boot-up. However, it couldn't display a thing on the screen. The Dell booted and I could see it accessing the HD by the lights, so there was activity; but without visual screen confirmation. I pressed the keyboard and entered in my Windows login password and saw the blinking HD lights; so it wasn't the same "blank void" situation I had at the start of the thread. The system was plugged in with RGB cables, I disconnected them and used the DVI port (into the GPU card) and still no picture. I unplugged the GPU card and switched back to the RGB cables and it booted like normally. Then it got me thinking. What if I booted back into BIOS and messed with the Primary Video options. If the factory default was Auto, maybe if I switched it to start up with Onboard/Card, then maybe it'll treat the GPU card differently and detect it as hardware. I restarted the computer w/o the GPU card w/RGB cables, loaded it into BIOS, From the Primary Video option, I changed Auto to Onboard/Card, saved and exited. With the GPU card installed, I loaded up the Dell with the same blank, same HD access; so I switched from RGB cables to DVI (which plugged directly into the GPU card) and I got picture! It's been an hour and the computer seems to be working fine, and restarting normally. For anyone else reading this from the far future, do not use the drivers and/or software packages from Radeon for a system this old, as some updates will brick the software and screw up the drivers. Use the drivers provided by Dell and Dell's website only, LINK HERE . I haven't seen any power cycling issues or Error 1-2-3 with the GPU card. It's up and running again. To sum things up: I wanted to thank [NAME] [NAME] de Orofor all the troubleshooting support. I will take your advice and shop around for a new Dell with all the links you've provided. Thanks again for everyone's feedback, patience and for those that stuck around this thread for so long.  
I am lost at the current situation. Here is a brief timeline. 1. Loaded into Windows like usual and working in Photoshop. Computer froze midway and I restarted the computer. Loaded up Photoshop, but this time, screen froze, followed by the entire screen turning into a pixelated mess. Hard freeze, couldn’t access task manager at all. 2. Restarted the computer, goes past DELL screen, then into blue screen of death. 3. Restarted the computer, goes past DELL screen, but again, blue screen. 4. Restarted the computer, but now, NO DELL SCREEN. Boots into blank screen, fan activity on main board and GPU card. 5. Restarted the computer, pressed F12 ever second to try and bring up BIOS or anything. Only got error code on the PC LIGHTS, which were 1-2-3, all green lights. Again, no screen activity, only physically lit code on the front of the Dell. 6. Consulted basic Google search, found that I was looking at a possible CMOS battery issue.  7. Bought a new CMOS Battery, carefully removed parts to place back in the Dell, like the HD/Fan on the SFF model. Replacement completed and put the Dell back together. 8. Booted up the Dell, again, no picture, no error code (unless I press F12 at start-up). Fans still going, but no activity light, just power light (green). The Dell just boots into a blank screen with no hard drive activity. I’m stumped and I’m hoping someone can help out. Again, Dell Optiplex 755 SFF. The only weird issue leading up to this might be sudden pauses of lag working in Photoshop before (which I assumed was just background Apps slowing things down). I was told it was the CMOS battery since it’s old. It’s been mostly in storage during that time and I dug up the Dell from storage during lockdowns.
Dell Optiplex 755 SFF, Boots directly to blank screen