Ensure the red wire on the ribbon cable aligns with Pin 1 (the dot) on the chip.
If programming "in-circuit," try plugging the motherboard into its power supply (but do not turn the PC on) to stabilize the ground. To help you get this sorted, could you tell me: What is the exact model number printed on your chip? Are you using a SOIC8 clip or did you desolder the chip? What software version are you currently running? Ensure the red wire on the ribbon cable
This confirms the chip is actually empty (all FF). If the blank check fails, your programmer cannot talk to the chip properly. Write the new firmware. Ensure the red wire on the ribbon cable
Use 90% isopropyl alcohol and a toothbrush to clean the chip legs. Ensure the red wire on the ribbon cable