Haier LE50H3280 will not power on

Do you consider it "within spec" for the standby terminal to have 4.25V instead of 5V? Also, am I checking the voltages correctly by leaving the ribbon cable connected that connects the power supply to the main board? I'm thinking it should be correct since I get no voltage readings when I disconnect the ribbon cable.
A couple more questions related to the PS board relay...how would I identify the PS board relay and what is the proper procedure to test it.
I don't have ( and am not having any success locating) a service/repair manual or schematic for this model TV...any help or suggestions of where I could locate one would be appreciated. Do you consider it "within spec" for the standby terminal to have 4.25V instead of 5V? Also, am I checking the voltages correctly by leaving the ribbon cable connected that connects the power supply to the main board? I'm thinking it should be correct since I get no voltage readings when I disconnect the ribbon cable. A couple more questions related to the PS board relay...how would I identify the PS board relay and what is the proper procedure to test it. I don't have ( and am not having any success locating) a service/repair manual or schematic for this model TV...any help or suggestions of where I could locate one would be appreciated.

I did notice the discrepancy of 4.25 volts instead of the 5 volts. Also noticed that your other voltage(s) was over the 12 volts. That is why I responded with the "within spec" comment. That could be the problem since it is almost 25 % below the nominal 5 volts.

Taking the readings while PS is connected would appear to be correct since you are placing the output lines under load conditions which usually lowers the voltage. I was surprised by the fact that you had no voltage without the ps being connected but maybe that is because it has to be connected to main board to turn it on! Oh, a relay is usually a small rectangular item with about 4 connections - two of them power the magnet and the other two are for conducting the current when the connection is made as the points close.

Getting a manual could be problematic and/or expensive since those suckers are usually not easy to get; and if you do find one, it is not a freebie. I am sure that you have googled it to the high heavens.

If that were my set and I really wanted to fix it I would look into the cost of a replacement PS board since they are subject to a lot of strain and compared to other boards are relatively inexpensive.

U can always check out ebay for good, used, working parts on the cheap.

Does your manual have a difficulty section regarding the diagnostics or blink codes or lack thereof? I did notice the discrepancy of 4.25 volts instead of the 5 volts. Also noticed that your other voltage(s) was over the 12 volts. That is why I responded with the "within spec" comment. That could be the problem since it is almost 25 % below the nominal 5 volts. Taking the readings while PS is connected would appear to be correct since you are placing the output lines under load conditions which usually lowers the voltage. I was surprised by the fact that you had no voltage without the ps being connected but maybe that is because it has to be connected to main board to turn it on! Oh, a relay is usually a small rectangular item with about 4 connections - two of them power the magnet and the other two are for conducting the current when the connection is made as the points close. Getting a manual could be problematic and/or expensive since those suckers are usually not easy to get; and if you do find one, it is not a freebie. I am sure that you have googled it to the high heavens. If that were my set and I really wanted to fix it I would look into the cost of a replacement PS board since they are subject to a lot of strain and compared to other boards are relatively inexpensive. U can always check out ebay for good, used, working parts on the cheap. Does your manual have a difficulty section regarding the diagnostics or blink codes or lack thereof?