L42VC04U Blinking Blue LED

[speedypro]

Re: L42VC04U Blinking Blue LED

Highly doubt it but ill check

[dick_barton]

Re: L42VC04U Blinking Blue LED

But I tried a main board, not psu, off ebay and same?

Pin / Voltage:

1: 0
2: 0
3: 0
4: 7.8v
5: 0
6: 0
7: 0
8: 0
9: 0
10: 0
11: 11.87v
12: 11.87
13: 0
14: 4.99
15: 3.4
16: 3.4
17: 5.13
18: 3.4
19: 5.13
20: 3.4
21: 5.13
22: 3.4
23: 0
24: 0
25: 0
26: 24v
27: 0
28: 0

Would the inverter board plays a roll with the flashing blue led?

Are these the voltage readings you are now getting from your power supply. I see that the 3V, 5V, 12V and 24V are all given in your list.
BL_ON/OFF is at 0V so no backlights.

[speedypro]

Re: L42VC04U Blinking Blue LED

Are these the voltage readings you are now getting from your power supply. I see that the 3V, 5V, 12V and 24V are all given in your list.
BL_ON/OFF is at 0V so no backlights.

That's correct. If I knew what causes a blinking blue light I'd know what to test.

[dick_barton]

Re: L42VC04U Blinking Blue LED

You may have a backlight error signal being fed back to the mainboard which is turning the backlights off.

Disconnect the main board and use a 1K resistors to bring up the power supply voltages and another 1K from +5VSTBY to BL_ON/OFF to check the backlights come on.

[speedypro]

Re: L42VC04U Blinking Blue LED

You may have a backlight error signal being fed back to the mainboard which is turning the backlights off.

Disconnect the main board and use a 1K resistors to bring up the power supply voltages and another 1K from +5VSTBY to BL_ON/OFF to check the backlights come on.

Let me replace FAN7711, I suspect that's the culprit. I'll confirm next week. Thanks.

[vinceroger69]

Re: L42VC04U Blinking Blue LED

I wa just reading this thread and seems that ic can cause issues
http://www.tv.quuq.org/forum/index.php?topic=6583.0

[speedypro]

Re: L42VC04U Blinking Blue LED

I wa just reading this thread and seems that ic can cause issues
http://www.tv.quuq.org/forum/index.php?topic=6583.0

Yup, I had a hot feeling about that, too.

[ReeceyBurger123]

Re: L42VC04U Blinking Blue LED

Yes could also be fan7529 (pfc) Ive had that work but as soon as its loaded the set aborts with flashing Led as Pfc dies. See if the Pfc starts then cuts off as bl tries to fire.

[ReeceyBurger123]

Re: L42VC04U Blinking Blue LED

I cant see the other Ic being failed as with no mb you get switched 24v ? Might also be worth checking these:

https://youtu.be/798-5GblfnY

[dick_barton]

Re: L42VC04U Blinking Blue LED

I cannot see why the FAN7529 is giving you a problem if you have close to 400V across the cap which you say you have. That would indicate the PFC circuit is working.
Neither can I see why there would be a problem with the FAN7711 since you also say you have all the secondary voltages of 3.3V, 5V, 12V and 24V

Personally I would run up the power supply and backlights with the main board disconnected to confirm on which board the fault lies.

Edit
I also noticed in your list that STBY (Pin 6) is 0V yet the power supply secondary outputs are all on??

[culcuhain]

Re: L42VC04U Blinking Blue LED

In the schematic posted, pins 1,3,5,7, 9 are linked and should show 12v. You have 0v.

[ReeceyBurger123]

Re: L42VC04U Blinking Blue LED

I cannot see why the FAN7529 is giving you a problem if you have close to 400V across the cap which you say you have. That would indicate the PFC circuit is working.
Neither can I see why there would be a problem with the FAN7711 since you also say you have all the secondary voltages of 3.3V, 5V, 12V and 24V

Personally I would run up the power supply and backlights with the main board disconnected to confirm on which board the fault lies.

Edit
I also noticed in your list that STBY (Pin 6) is 0V yet the power supply secondary outputs are all on??

I have put and had the fan7529 fail under load at start up pfc starts then when bl is loaded it cuts off. And I have a video of that soon. Do you have a scope op ?

[speedypro]

Re: L42VC04U Blinking Blue LED

Part came, fitted but same thing: standby light comes on then the blue light flashes. Cycle repeats.

[ReeceyBurger123]

Re: L42VC04U Blinking Blue LED

You got a scope ?

[speedypro]

Re: L42VC04U Blinking Blue LED

You got a scope ?

No pro tools here Im afraid. Im currently watching your video to find clues.