HT (High Tenson) supply will require to replace.

This is an error for no horzontal signal , high HT or poor regulation. You need to check on the +B and see if the SMPS- power supply is stable. If so on remove power cord from supply and after 15 mintues when it is switch on does the set power on to shut down. If so there is short or fault in the H section.
This will require tests on the Horz. section for right frequency and regulation.

you can use a breaker bar and a socket to relive the tenson or a wrench the only way to relive the tenson is by turning the belt tensoner and loosing the belt.

It is clear with your question that the magnetron in the microwave is not turning on where as all the functions are working normal,check HT diode grounded with the high voltage capacitor by replacing the same,still the problem persists check and replace magnetron.

try to visit the Samsung service center located at your place..

If you fuse had gone off then it is most possible that the set has a failure within, This can a short in the powerr supply section or the high voltage section. So first of all remove the back covers and use a multimeter to check on the power supply which could be swittch mode power supply. You must look for short in the surge protector, the filter capacitors, the rectifiers, teh main capacitors or the SM drives. If these are fine discconnect the HT side and switch on to confirm the power supply. If fine check on the HT for failure of the drivers/ capacitors in the section by a contiinuity, voltage test. Do it carefully, get help if not familiar. Good day

It sound as if your set is stuck in the standby mode and the cause can be many fold so i'll try and advise you on how to begin your diagnosis.
Two major areas for your attention are the power supply and line output stages. Over voltage or over current will cause the power supply to shut down and we need to isolate the culprit. To elimate the power suuply disconnect HT + feed to line output stage and connect 100 watt lamp from power supply HT+ to chassis (Ground) If lamp lights at reduced brightness and HT+ is Between 100 and 140 volts then power supply is most likely ok. If lamp not lit or running at full brightness then power supply fault exists. Check all electrolytic caps and chopper transistor also check any high Ohmic value resistors (100K or more) for open circuit. If fault not in power supply most likley cause is short circuit line output transistor. You will require a multimeter, soldering iron and the service manual for repairs of this nature. WARNING very high voltages exist in these circuits. Please take care. I'ts the volts that jolt but the mills that kill. Your friends still love you so you owe it to them to keep safe.

The Hissing is the High Tension electricity. Sounds as if this section has failed. Developed a partial short of some sorts in the HT section or Power Supply. It seems that your unit has some sort of HT side, PSU fault, or a problem to the HT section that is shutting down the Power Supply Unit, PSU. This happens so that no further damage, and possible fire will occur.
You need to take the unit to a reputable service centre/man and ask for a firm "Quote" for the work to be done.

The reason why the standby light comes on by itself is for preventing the set from damage. Most likely the HT transformer is unable to produce the high voltage required for the CRT Display (approx. 11KV) or the 3 coils on the back end of the tube (RGB), The Ht circuit has its own set of fuses & that should be checked first, before checking the rest of the set...sodeep

this is almost certainly a ht proplem chech ht transistor by removal then turn tv on it should if so replace transistor be carfull high voltage may be still present on capacitors

145-203 ft.lbs.