I have a hitachi 62" LCD tv.when you turn the tv on,the power light flashes for a few seconds then the temp and lamp lights flash.The tv does not give any sound or picture.

Pls check that model number........the problem description does not match that of a 1999 crt proj tv.........I believe yours is a newer lcd projection around 4 or 5 yr old?? Lamp light flashing on any brand is indicative of the lamp not lighting . The lamp is the most likely cause,but the ballast board can cause this as well..................you should see an access door refer to owner book of the correct model and you can replace yourself...........it may cost around $200 and avaiolable at encompass parts .com Hitach distributor

The lamp is likely blown - it is loacated behind the front panel and can be pulled out to check - unplug set and do not touch front of lamp.

It sounds like you have a thermal issue. The TV is getting too hot or the Thermal Fuse is bad. The thermal fuse detects the temperature in the TV and tells the TV to shut down if it thinks it is too hot. Most likely caused by poor ventilation or clogged fans from household dust. Try moving TV away from wall or cabinet first, if this does not fix the problem, clean ALL the fans in the TV. If problem still persists, replace the thermal fuse.

Blinking temp light means bad lamp fan. Needs replacement

first step to take:
refer to the user's manual to find: How to replace the lamp?
and second replace the lamp. www.andrewselectronics.com. prefer original ones.

the cooling fan could be going out

Good Day;
Try this:

Symptom: All Front LED indicators are flashing in sequence: Power-->Temp-->Lamp-->Power......continuously
Cause: Replace Lamp . This symptom may happen all the time or it may be intermittent. It is normal if it occurrs from time to time, See OG under TV Front Indicators explanation notes.
Good Luck, big IRISH.

need new lamp

My Hitachi Model 50V500 led's ligths temperature and lamp blink when power is turn on.Have no picture or sound, followed the reconmended procedure disconnected power
for 30 seconds and reconnected.

The fan may have went bad. If it's out of warranty you may open it up and try and blow some dust out of the fan to see it that may do the trick if not it may need to be replaced. Westexaudioelectronics.com