Job Number

0209-57

Equipment type

Television – 14 inch

Maker + Model #

Telefunken Chassis 417

Made in

Germany

Client Info

Josephine Mahoney, Mosta 21412848

Date in

26-Sep

2002

Date of repair

05-Oct

2002

Date out

08-Oct

2002

Comments

(next door neighbour of Aunt Margaret)

BAD

1

 TV volume rise to maximum after 1 to 3 hours and becomes uncontrollable. Channels could not be changed, and TV seems to block up

2

3

GOOD

1

 Good picture, sound, tuning, deflection and syncro

2

Full repair description and observations

1

 The Sound circuitry an Iv was first analysed, but it seemed to be everything working well…

2

 Then the jungle chip seemed to get very hot and it fell in suspect, butwhen cooled with cooling spray, no effect took place. 

3

 On thinking about it, the fault was around the microprocessor, since the problem was with control. Once, freezing cold spray around the microprocessor circuitry, made the TV to work again from its blocking mode

4

 The microprocesser itself did not get very hot, but there was a transistor and a resistor which were very hot. The transistor was found to give 0.85 forward Voltage (usually they are round 0.6-0.7) while the resistor in concern was a little higher (+20%).

5

 The transistor and resistor were replaced, and resoldered most point around the microprocessor area. This solved the problem and the tV forked for 8hours for 3 consecutive days without any problem.

Repair summary

Transistor and Resistor faulty near microprocessor circuitry. Dry joints could also been the problem

1

n/a