1. STBY 5V (CN801, #2, 5v)
2. PS_ON (CN801, #1, 3.3v-0v)
3. VS_ ON (CN802, #6, 0-3.3v)
4. Panel should illuminate briefly

Will not be run with the “X” or “Y” main disconnected. 

The SMPS will shut down immediately. However if a meter is first connected to the test point when power is applied it will read the correct voltage briefly before shutting down.(You have enough time to check key voltages)

[Do not reconnect any connectors to SMPS or Y/X Boards until power has been turned off long enough for Vs to drop below 10V or damage will occur to X or Y Boards.]

SMPS Over Current Protection

If a short circuit occurs on either the VS or VA voltage lines, the SMPS stops operating, but should not fail. When the short circuit is removed from the source line, the Power Supply will operate normally again.

Many SMPS Supplies are replaced needlessly.

When troubleshooting, it’s very important to first check Vs, Va, Vsc & Ve If Vs is missing (0V), disconnect power and check for short. Use ohm meter to measure resistance while disconnecting Y-Board & X-Board supply feeds one at a time.
Turn Power On and Test SMPS with shorted connector removed for correct Vs voltage verification. (It may only come up briefly but to full level). Be careful not to reconnect power connectors until Vs falls below 10V

If Va is low or missing, disconnect power connectors to Address Boards and Check to see if SMPS Supply is restored. (Note Va feed normally passes through the Y-Drive to the Address Boards (Logic Buffer Boards)

If Vsc is low or missing and Vs is OK, the failure is with the Y-Board since the Y-Board generates the Vsc voltage from the supplied Vs

If Ve is low or missing and Vs is OK, the failure is with the X-Board since the Ve is generated by the X-Board from the supplied Vs. (Please note: In some
rare cases the Ve is generated by the Y-Board fed to the X-Board.)

Other SMPS Voltages
Check Low Voltage feeds to the Main Board and other supplied Assemblies.

TROUBLESHOOTING VIDEO PROBLEMS
1. Verify Video Operation
a) Customer Picture Test (if available)
b) “Display” (If display is OK source is suspected)
c) Substitute with known good Source (external DVD or Signal Generator)

a) If Logic pattern is NG; Logic board, Logic buffers or Panel are suspect.

b) If FBE patterns is NG and Logic is OK; Main or LVDS cable are suspect.

c) If both are OK it is likely a source issue.

Using Test Patterns in Service Mode

Fast Track Troubleshooting Manual
1. Check/Adj. VS, VA, VE, & VSC according to Panel Label and Diffusion test. (see bulletins for any special notes before making changes)
2. Check/Set Option Bytes:
ENTER SERVICE MODE 
a) Customer Remote: Power off; Mute, 182, Power On

b) Service Remote: Power On; Info, Factory.

Allow the unit to warm up 15 to 20 minutes
Access the Burn Protect Sig. Pattern in Cust.
Menu.
Adjust the Vs volts until screen errors are gone in both dark and bright areas.
Adjust the Vs volts within +/- 10V on the panel label