Sharp LC-C4655U Flashing OPC and Power lights.

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Removing D9701 does result in 3v at PS_ON. The diode tests 0.60 one way and 0 the other.

[R_J]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

did the power supply turn on as well? If it did, check if there were any voltages on LB plug. If there are no voltages, try supplying 5v to stb on the inverter, you can use a 470~1k resistor if you like.

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Yes. When I hit the power button it did. Lots of clicking when I first plugged it in. After hitting the power button I had 12v and 60 but nothing at the LB plug.

I did not have to start with the chan/vol

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

I don't have a resistor. What's the best way to do this?

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

With STB 5v. Lights turn on but they turn off and back on every 10 secs or so. LB on inverter:

Pin1 - 0
Pin2 - 5v
Pin5 - 3v
Pin8 - 3v

[R_J]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Pin 5 is the error pin so I suspect there is a problem on the inverter, if the LB is still connected to the main board it is likely telling the main board to shut down

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

You can try connecting the PS_ON 3.3 direct to the stb on the inverter and see if it turns on the inverter, if that doesn't work I would try 5v direct to the stb

Sorry see above. I just jumpered 5 v to it.

[R_J]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Sorry see above. I just jumpered 5 v to it.

I saw that so I changed my post.

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Ah. Hence the ERR label. So main board is probably fine? What types of things on the inverter can cause the error? And yes I kept the plugs in when I jumpered. Just shoved in the top.

[R_J]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

The first thing I would check are the transformers, The transformer has two secondary's so check the resistance of each winding, they are usually around 1000Ω so check each transformer and see if one of the readings is not like the others.

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

I think I'm checking these right? didn't find a diagram in service manual. Look at picture to see if I'm doing right. If so I'm getting consistent readings on all of them.

[R_J]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

If I remember this should be the secondaries

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

No that doesn't work. Here is the only thing I could find on the transformers.

2874026700 transformer

[R_J]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

The original way you checked the transformers is the correct way so I suspect they are ok. On these inverters, transformer failure is common, but so is having a bad ccfl in the panel, or even bad connections between the ccfl tubes and there sockets can cause a problem.

[berrmich]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

The original way you checked the transformers is the correct way so I suspect they are ok. On these inverters, transformer failure is common, but so is having a bad ccfl in the panel, or even bad connections between the ccfl tubes and there sockets can cause a problem.

Anyway to figure that out?

-Mike

[R_J]

Re: Sharp LC-C4655U Flashing OPC and Power lights.

Anyway to figure that out?

-Mike

Remove one of the transformers so you can see and check the windings, with it removed there will be nothing else effecting the readings, sometimes transformer pins are just used for mounting and are not connected to a winding.
If all the transformers checked the same I suspect they are all ok, 1.7k seems fine, if one was 1.5k or something like that I would suspect it was bad.

I suspect it is like this picture