Help me Identify this part

[joeshannallie]

I have a RCA 37" LCD tv that is completely dead. No standby light or anything. The part circled in red was getting very hot but it is not now. No voltage is showing from it. The exact part under it shows 0v on the first pin 002v on the second pin and 004v on the third pin. The marking on it shows EH16A 015F72,
Can not find anything on Google for it. Can someone lead me to the service manual for a RCA 37LA30RQ tv?

[zacheriaj]

Re: Help me Identify this part

U1 is a voltage regulator unsure of the rating due to the picture. The silver can is an aluminum SMD capacitor 16v 100uF

[budm]

Re: Help me Identify this part

Check the resistance reading between the two legs of that cap to see if it shows low resistance.

[joeshannallie]

Re: Help me Identify this part

Thank you for the reply. What do you need to know to properly id it? I posted what was wrote on it.

[joeshannallie]

Re: Help me Identify this part

Thanks Bud for the reply. I was hoping you would. If I did it right, I only have a digital volt meter. I put the meter on ohms and then I touch chassis screw with the black probe and then touched each of the caps, Is this Right? The E1 read 00.5 on one side and 13.7 on the other side. The one marked E6 read 00.5 on one side nothing on the other side. Then I put red probe on chassis and touched E6 with black probe and it read -71.2.

[kasfamily]

Re: Help me Identify this part

U1 is AZ1117- 3V3

[budm]

Re: Help me Identify this part

OK, per your picture, the regulator with red circle, put the Ohm meter red probe on the big tab output pin), the black probe on the chassis and take the reading, make sure to report if the reading is in Ohm, K Ohm.

[joeshannallie]

Re: Help me Identify this part

Ok the one in the circle shows 13.7 and beeps.

[Agent24]

Re: Help me Identify this part

Sounds like the regulator could be bad

[budm]

Re: Help me Identify this part

It is either very heavy load or the IC is bad you need to remove the old IC and check the resistance of that big copper pad where the big tab of the IC was connected to see if it still shows 13.7 Ohms.

[joeshannallie]

Re: Help me Identify this part

Thanks for all the great advice. Can someone please look at the power supply and tell how I would go about shorting what pins to see if the backlights will come on. The inverter wire connects to the main board.[/IMG]

[budm]

Re: Help me Identify this part

You need to show the inverter board connection since this power supply does not have the BL_ON signal that get routed through the power supply board.
To get the backlights to come on, you will need to apply 3VDC to PS_ON pin through 100~500 Ohms resistor and 3VDC to the BL_ON pin through the resistor also, and may be the Dimming control pin also. You must disconnect the PS_ON pin and the BL_ON pin to the main board otherwise the main board will force those signal lines LOW and will not allow them to go HIGH.
Do yo have 24VDC output for the inverter to work?

[joeshannallie]

Re: Help me Identify this part

The only voltage at the wide connector on the supply is at the 5v pins and the all show 4 and it also shows 4 at the ps on pin and 4 the sb pin. When I touch the red probe to the screws that have the ics(not know what they are called) attached to the heat sinks it shows -7 . But the ones next to the wide connector shows 0. Will 220-ohm 1/2 watt resistors be ok? Where do I get the 3v from?

[joeshannallie]

Re: Help me Identify this part

The canister capacitor that is laying down on the board only shows 007 on the meter. I guess I tested it right. Held black probe on one of the screws as ground and then touched the legs of it with the red probe. One leg said -007 the other leg shows 007. Thanks for the replys tonight. It is bedtime for me. Get back on it tomorrow if anyone has any suggestions.

[budm]

Re: Help me Identify this part

OK, before going any further, you must have 5VDC at +5VSB pin. Are you measuring the voltage with all the boards connected in place? what do you use for the ground for the meter? Do not use heatsink for checking the voltage, that heat may be connected to the LINE (HOT DEADLY PRIMARY SIDE).
If you are only getting 4V on the +5VSB, then there is the problem that you need to fixed first since the standby power supply also supplied the voltages to run the 24V SMPS IC and the PFC Voltage booster. The PFC Voltage also needs to function for the 24V DC power supply to function, there are so many circuts that have to function together for the set to work, you are jumping ahead on trying to get the backlights to come on, right now are not getting the standby LED to come on so there more to test before getting to the backlights, 24V, INVERTER testing. You must have the 5VDC on the +5VSB first. Is you meter's battery good?

[budm]

Re: Help me Identify this part

The canister capacitor that is laying down on the board only shows 007 on the meter. I guess I tested it right. Held black probe on one of the screws as ground and then touched the legs of it with the red probe. One leg said -007 the other leg shows 007. Thanks for the replys tonight. It is bedtime for me. Get back on it tomorrow if anyone has any suggestions.

Well, you need to learn how to check the primary (Hot side), and secondary side and what to use for ground ref point for each side of the circuit before you get hurt.
When you work in primary side, the main filter cap negative leg is the ground ref point for the primary DC voltage testing point, that cap should have 170VDC MEASURE RIGHT AT THE TWO LEGS OF THE CAP. When you work in the secondary side, you can use the chassis as the ground ref point.
At least you should plug your TV into GFCI outlet to protect yourself.

[joeshannallie]

Re: Help me Identify this part

Well I assume the battery is good. If it only shows 4 how can I get it to show 5v. Sorry for all the questions. I was just using one of the screws as ground that has some of the metal frame connected.

[joeshannallie]

Re: Help me Identify this part

Thank you for the advice. I am about to give up on it and just order a ps board and main board from Ebay for $45. I just love the challenge and can not stand to give up on it when it may be something simple.

[budm]

Re: Help me Identify this part

Disconnect all the connections to that power supply board, just have 120V feeding it and see if the voltage will come up to 5V. What kind of meter are you using and what scale of the DCV range is it on, 4V reading sound like it is set to very high V scale. it should show 4.XX Volt, not just 4V.

[joeshannallie]

Re: Help me Identify this part

It is a Cen tech DT-266 meter and it is set at DCV 1000, That is the only DCV setting on it. May not even be good enough to use on this type of electronics.