故障现象：海鸥ＤＦ－３００ｘ（机号：３４１２２６）快门不释放，变焦头（９４５９４８７号）的变焦与调焦部位之间松动。 检查及维修：打开电源开关（Ｓ６），卷片上弦，轻按快门钮（接通ＳＯ），取景器内ＬＥＤ灯在所调的所有档位和模式上都亮，继续向下按快门钮（接通Ｓ１ Symptom: Seagull DF-300x (unit number: 341226) shutter is not released, the zoom head (9459487) zoom and focus between the loose parts. Inspection and Maintenance: Turn on the power switch (S6), wind the coil, tap the shutter button (ON), the viewfinder LED lights up in all positions and modes adjusted, press the shutter button down Turn on S1