gtr777Our SONY HCD-GTR777 Service Manual provides the important servicing information and operating instructions you need to diagnose and repair your malfunctioning or failing unit. MostHCD-GTR777, GTR888: E2, E51, AR 4-265-401-0[] Soldering irons using a temperature regulator should be set to HCD-GTR777, GTR888: MX 4-265-401-2[] about 350 °C. Caution: