When is it necessary to contact professional support for an E1 error on my HP LaserJet M1136 MFP?

It is necessary to contact professional support for an E1 error on your HP LaserJet M1136 MFP if: 1. You have exhausted all troubleshooting steps (clearing jams, power cycling, roller cleaning, trying different paper) and the error persists. 2. The error appears immediately upon turning on the printer, even without any print jobs. 3. You suspect a faulty paper sensor or other internal hardware damage. 4. You hear unusual mechanical noises (like grinding or clicking). 5. You are uncomfortable disassembling any printer parts for deeper inspection.