Mikkhail, to check the capacitors, you need an impedance meter. A regular multimeter will not do. It may or may not show continuity. To determine which voltage to set your multimeter. This depends on where you take the measurement. If the symbol you refer to looks somewhat like this -->|-- that is the symbol for a Diode. It should be in the instructions for your meter on how to use it to test diodes. Now for your TV, I suggest you first check the Fuse F601 and replace it with a 250V 10A fuse as needed. Step 3 of the guide you listed above shows the location of the fuse on your board. Use your multimeter to check for power. Caution, here you are still dealing with 110V AC so be careful, otherwise you might have a hair raising experience. Then check the Power Failure Circuit
This unit is equipped with a Power Failure Detector function included in the CPU which checks for an abnormal condition in the chassis power supplies.
If, while the power is on, a failure is caused by any of the following that results in a low voltage supply, the CPU will turn the unit off in 1.5 seconds to prevent further damage.
- Failure within the power supply circuits
- A short circuit in the load side from the supply.
1. Power Failure 1. Detected voltage failure for analog and digital circuits (Connected on IC801 pin 32.)
2 Power Failure 2. Not used on this model
Check the following if the unit is turned off by the power failure detector.
1. Disconnected the AC power cord for at least 10sec
2. Connect a DC voltmeter to the circuits shown in the attached image
3. Press the Power key and check for the proper voltage supplies.
4. If any of these voltages is low, the power failure detector should turn the unit off within 3 sec
I also attached the block diagram of the power lines. This may help you to properly measure the voltages. Those are DC voltages. Hope this helps to get you started.