Tv Power Standby Test; Tv Power On Sequence Test; Smps/Panel Backlight Test - Samsung QA55Q900RBWX Series Service Manual

4-3-1. TV POWER STANDBY TEST

1. TV in Standby
Standby LED Indicator (Note: Status can be changed in user menu and may default off)
9
2. If Not Lit: (and should have been lit with status setting)
B350V Line / One Connect Cable
9
3. If missing:
One Connect Cable status
9
4. If TV does not power on:
Resistance on SMPS
9
5. If fuse is open:
replace SMPS.
9
6. If fuse is OK:
Standby: A13V (Always On) supplies to Main Board.
9
replace Main Board
9
7. If still missing:
replace ONE Connect Cable.
9

4-3-2. TV POWER ON SEQUENCE TEST

1. Power TV On
9 PS_ON .2Vdc (when off) changes to 3.3Vdc (on)
• Note: Will stay On for short time when powered off.
2. If voltage error or no change:
Jog Function & IR Control Test
9
3. If OK :
Check a connecting status of One Connect Cable between TV and OC
9
Remove and reconnect the AC power cord
9
Change One Connect Cable
9
4. IF TV still won't power on
All A13V supplies for approx. 12.7VDC(CDR)
9
All Vamp supplies for approx. 18 VDC
9
5. If any wrong voltages:
Replace SMPS
9
6. If still wrong voltage:
replace TV Board and OC Box
9
7. Backlight ON
9 Backlight On/Off
replace TV Board or OC Box
9

4-3-3. SMPS/PANEL BACKLIGHT TEST

In 2018 OC model, system power is supplied by OC Box.
9
We can't SMPS/PANEL Backlight test without OC Box and TV Board
9
If we use OC Box and TV Board, It is the same test condition as TV POWER SEQUENCE TEST
9
FUSE after first removing AC power cord.
0V Off to 3.4Vdc ON (CNM803 PIN.26)
4. Troubleshooting
4-5