Complete disassembly of SAMSUNG SCX-3400/3405. You can remove and repair or replace any unit (laser unit, thermal block, gear unit, paper pickup unit, and any board). My videos are for those who want to refill the cartridge themselves or repair the printer, MFP, copier, etc. There are videos with various faults. If you have any questions about a particular model - please contact, I will try to help. E-Mail - [email protected].