Heating Failed Cycle Power Target Message from a "Disman - 01" Is a DIY Ender 3 Clone

Hi All,I am new here and will be visiting this board more often:) Anyway I had a Thermal issue with a "DIY Disman - 01"I ordered a secondhand/open box printer from a Main Manufacturer and they sent me the wrong one. I received a "DIY Disman -01". It shares a lot of Creality components for example the Main Board is Creality V2 .2.1 (And don't worry the company said I can keep it and they shipped me the one I originally ordered) But I started to tinker with this "Disman -01" ) (Looks just like an Ender 3 Pro and has duel z rods and Auto Leveling etc.. So I don't want to just scrap it yet) The printer did not come with a PSU, but I did a youtube search and found out that I can use a PC PSU rigged up. I had an older gaming PC with a 750w power supply hooked up to the 3D printer's main board with the two of the Positive wires twisted together and two Negative wires from the 12v PC Jack and twisted them together.With that said, I started the printer up, everything seemed fine until I did a manual Temperature adjustment so I could test some filamanet and the extruder and all. I ended up getting the error message "Heating Failed! -Temperature was not met on the nozzle or bed son enough inspect and verify ambient conditions....." Now I did research on it and I checked a few things out. I tried to heat the Bed to 60 and didn't have an issue. But I have issues when the hot end gets above 130 and that message appears and the higher it goes the slower it gets. But my main question is that, could the makeshift power supply of hindered this? It was a high-end modular one with 750watts. Or could it be possible other issues, like thermal runoff, or just a bad hotend. I also checked the ambient temperature and left the printer on and it seemed to read it correctly.The PSU Power supply is about 10 years old but was never used a lot. I would consider buying a regular Ender Power Supply if I knew if this could be the issue? And then again on the other hand, I just don't want to dump money in it especially if it is a crappy 3d printer. I could always sell it for parts or keep it for parts but would love to get this working lolThanks in Advanced,Rosco :)