Advertisement
(2) Logic main board
! Set the logic main board as Figure 6 shows.
fl Check for the test PROM installation status and clock jumper setting.
@ Connect a 4-pin connector cable between LD01 of the logic main board and the linear power supply.
(or SMPS).
fl Connect while the linear power supply (or SMPS) is turned off.
# Turn the linear power supply on and supply 5V power to the logic main board.
Check if LED, LD2000 on the left top of the board blinks at about 1 second interval. If the logic board
doesn't operate normally, the LED will blink too fast or not be lighted on.
$ Measure the waveform of each test point on the board, and then compare them with the appended
waveforms.
You should examine the waveforms of all test points.
If the waveform of a test point is different from the appended waveform, or the voltage level is low, do
not proceed to the next examination step and check other abnormal test points.
% Perform RESET examination.
Press and hold SW2001 reset switch for 5 seconds to turn the LE2000 of the logic main board off. Release
the switch after 5 seconds and check that LD2000 blinks. If no problem is found, finish the examination.
^ If the waveforms of all test points are output properly and RESET examination is complete, turn off the
linear power supply (or SMPS) to finish examination.
& After all examinations are complete, perform as follows.
- Reset the clock jumper to external clock.
- Reset the internal/external pattern jumper to external pattern.
- Reset the NTSC/PAL mode jumper to PAL mode.
Samsung Electronics
Circuit Operation Description
5-39
Advertisement
