ITI/NCVT Mechanic Consumer Electronics (AITT Theory) case studies
ITI/NCVT Mechanic Consumer Electronics (AITT Theory) · Put your knowledge to work in context.
The All India Trade Test (AITT) in Mechanic Consumer Electronics is the theory assessment taken by trainees who have completed the NCVT-recognised trade course in consumer electronics servicing. It tests whether you understand the trade, not just whether you can follow a wiring diagram: safety and workshop practice, electrical fundamentals, semiconductor devices and power supplies, analog and digital circuits, audio and video equipment, white goods and home appliances, communication and mobile devices, measurement and fault diagnosis, and installation and customer-facing service work. The ITI/NCVT Mechanic Consumer Electronics (AITT Theory) case studies are 5 cases and about 3,341 words.
15 V Standby Rail Collapses Only Under Load in a 32-inch LED TV
A 32-inch LED TV is brought in dead. With the main board disconnected, the standby 5 V rail measures 5.02 V and the 12 V rail is absent, which is normal for standby.
746 words, about 4 min2Protection Relay Opens After Ten Minutes at Moderate Volume
A 100 W per channel Class AB stereo amplifier works for about 10 minutes at moderate volume, then the protection relay opens. At idle, DC offset at the left speaker terminal is 8 mV and at the right 15 mV; bias measured across 0.22 Ω emitter resistors is 6 mV on the left and 14 mV on the right against a service spec of 12 mV.
652 words, about 3 min3Microcontroller Resets When an Off-Board 5 V Relay Turns Off
A custom controller board uses an ATmega328P at 16 MHz, a 5 V AMS1117 regulator fed from 12 V, and a 5 V SPDT relay. The relay coil is mounted off-board and connected by a 15 cm two-wire lead; a 1N4007 flyback diode is fitted at the relay, but the return wire shares a 0.3 m ground trace with an LM35 sensor and the MCU ground pin.
700 words, about 4 min4Washing Machine Trips the 30 mA RCD Only During Spin
A two-year-old front-load washing machine with a 2 kW heater trips a 30 mA RCD at the distribution board during the spin cycle, not during wash or drain. The RCD also protects a fridge and a freezer.
620 words, about 3 min5Phone Charges at 0.05 A After a USB-C Port Replacement
A customer brings in a three-year-old Android phone that stopped charging. Another shop replaced the USB-C port.
623 words, about 3 min