Teac 3290I, Service Manual

Page: 58 / 83

TCL-Thomson Electronics R&D Center (Shen
’
Zhen Lab)
Page 6 of 12
TCL-Thomson Electronics
These drawings and specifications are the property of TCL-Thomson Electronics and shall not be reproduced or copied or
used as the basis for the manufacture or sale of apparatus or devices without permission.
8. 5EWT for trapezium correction.
* Apply NTSC signal to adjust these registers for NTSC geometric
2.8 EHT/HEW ratio test
： （
test with PC program
）
Equipment requirements : High Voltage Meter (Range: 0 - 40kV)
、
High voltage test
stick (1000:1)
、
Adjustable DC power supply
、
Dummy deflexion coil(as same
inductance as CRT which use to product).
Test method
：
a. Mount the EHT cap onto the fixture and connect the EHT meter. Plug in the
dummy deflection coil. Connect the DC meter across C417.
b. Switch on the chassis and measure the ratio of EHT/HEW at I
b
= 0 ( brightness
、
contrast are minimum).
Here, the HEW is the DC voltage across C417.
EHT voltage V, HEW voltage V1.
d. Apply PC program, V/V1 need satisfy request below
：
EHT/HEW (V/V1)
29276P5 44-29RFLS-OR3A
A68QDL082X012(B)
2.9 X rays over voltage protecting circuit test
Test method
：
When TV ON with color bar signal, add more than 27V DV to C417 , machine could
enter into protection mode, otherwise please inspect X rays over voltage protecting
circuit .
2.10 PS line polarities test
This test only the machines which will sell to NAFTA should be done.
Test method
：
Connect as drawing below
：
DX 2.2k
Power Supply jack M
TO F801
Plug the card power connector plugs to Power Supply jack M, and use multimeter pen
touch F801 random pin, then LED DX should luminescence and clew with sound,
DC Power Supply
9V
- +
Sound clew equipment