The toughest faults to discover are those that occur only Occasionally—intermittent occasions. They may be a result of undesirable connections, dust, Grime, corrosion or simply damaged wiring or connectors.Ph?n l?n m?c tiêu chung c?a ng??i ch?i cá c??c t?i 123B là h??ng t?i s? chi?n th?ng. M?c dù có t? l? c??c cao h?n nh?ng n?i khác nh?ng k