Sharp LC-32D12E Standby Light Just Flashing

[nogger]

Hi all, just had a Sharp LC-32D12E dropped on my by a neighbour which wont switch on , just flashing the (white ) standby light continuosly.
Its got a Vestel PW26-4 in it & i have been all over that board (and all the previous posts on here) but i think i'm about to dissapear up my own exhaust pipe soon !

I have 24v to the back lights on plug PL802 & 3.3 volts to the inverter board but no BL_ON signal at all. Measuring the voltages on PL816 i seem to have most voltages when switched on with a couple of exceptions as below. I can't make my mind up if this is because of a faulty mainboard (17MB61-R) or faulty PSU or is it the inverter ? As the inverter isn't getting a BL_ON i have discounted that for the moment. Voltages on PL816 with the fault condition present are:

Pins - 1,3,5,7,9 GND
Pin 11 - +12v
Pin 13 - 0v (Marked as 33v on drawing but no components fitted)
Pin 15 - 3.3 (3.3V_STBY SIgnal)
Pins 17,19,21 - 5V
Pin 23 - GND
Pin 25 - 3.3V (marked as KEY on drawing ?
Pin 27 0v


Pin 2 - GND
Pin4 - 8.7v (SW-SWITCH Signal)
Pin 6 - 0V (STBY Signal)
Pin 8 - 0v BL_ON Signal)
Pin 10 - 3.3V (DIM_PWM_ANAL Signal)
Pin 12 - 11.75 (+12v_1 Signal)
Pin 14 - 5v (+5v STBY Signal)
Pin 16 - 3.3 (+3.3 STBY Signal)
Pins 18,20,22 - 3.3v (VCC_3v3_ON Signal)
Pin 24 - GND
Pin 26 - +24v
Pin28 - 0.7-1.4 ( A/D DIM SEL Signal)

I have changed the electrolytics even though they all looked ok, just can't understand whats going on especially the 0v on the STBY pin (pin 6) I 'm tending to veer towards the mainboard being at fault ?

Any ideas welcomed, this is the first VESTEL PSU i have worked on & can't say i'm enjoying it.:-)

Thanks in advance

Graham







































































1

[tom66]

Re: Sharp LC-32D12E Standby Light Just Flashing

Whenever you get a blinking LED on a Vestel it indicates a detected fault of some kind, that is the main board has sensed a problem and has shut it off. Usually it's the main board at fault. I hate Vestel TVs - although they are usually easy to fix.

If the PSU output voltages are good I'd suspect the main board. Sadly (or is it gladly?) I have no personal experience but the boards are pretty cheap.

http://www.ebay.co.uk/sch/i.html?_sa...17mb61&_sop=15

You must match up the HDMI input counts and other things as there are several variants.

One thing you could try before swapping boards is a firmware update - however I've not done this before on a Vestel TV (or any other TV) so can't offer advice.

Shame on Sharp for using a Vestel chassis.

[nogger]

Re: Sharp LC-32D12E Standby Light Just Flashing

Hi Tom, thanks for the quick reply.

As i can't get the set to come up how can i do a firmware update ?

Like i said, i'm veering to towards the mainboard.
Graham

[tom66]

Re: Sharp LC-32D12E Standby Light Just Flashing

I think you have to do it through the headphone port or VGA port with an adapter cable... not sure if they provide it openly - think it is for service techs only. Does the TV have USB?

[vinceroger69]

Re: Sharp LC-32D12E Standby Light Just Flashing

check this found on another post
D881 (893) s/c. Print side there is a 0 ohm smd link o/c. .

[tom66]

Re: Sharp LC-32D12E Standby Light Just Flashing

Vince is that main board or power board?

[nogger]

Re: Sharp LC-32D12E Standby Light Just Flashing

HI Vince, i checked the diode (UF5402) by removing & measuring it, it checks out ok. also the O ohm link is ok.

I have read all the posts on here that i can find to do with this vestel board ,I just wanted to run those voltages past someone (fresh pair of eyes and all that). Anyone have any thoughts on the voltages i posted especially the STBY pin (pin6) .

Graham

[vinceroger69]

Re: Sharp LC-32D12E Standby Light Just Flashing

Vince is that main board or power board?

https://www.badcaps.net/forum/showthread.php?t=19260
http://www.tv.quuq.org/index.php?ind...n_view&idev=42
also check IC830(FAN7711N)
and this may be of help?
After 5 failures the TV goes into failure mode and does not even try to light the lamps.

TV into service mode to clear the error.
To enter service mode power on while holding down Volume - and input select until a 'K' appears on screen. Then press vol- and prog- to enter service mode.
Using the remote use the down button to select page 10/11 then use the prog button to select clear lamp error and right button to clear it.
To exit service mode power on again with Vol- and Input Select held down

[tom66]

Re: Sharp LC-32D12E Standby Light Just Flashing

Does STBY change at all when it is plugged in? Or is it always zero?

[nogger]

Re: Sharp LC-32D12E Standby Light Just Flashing

Hi Tom, with the plug from the mainboard plugged 0V, with the plug removed & measured directly on the PSU socket pin 0v & during t his time the led on the front just flashes away fast.

Is this pin an output or an input ?

[tom66]

Re: Sharp LC-32D12E Standby Light Just Flashing

Should be an output from the main board to the PSU.

Low might indicate TV -not- in standby - so the main outputs switched on. So this seems OK.

I know Vestel TVs do a self-test when first plugged in and it's likely this is failing.

If all the outputs are OK something else is failing on the self test.

I'll have a look at the schematic for the PSU to figure out whether it should be low or high.

[freakaftr8]

Re: Sharp LC-32D12E Standby Light Just Flashing

I worked on one of these a while ago. Have you tried holding down power and vol- for 10 seconds upon power up? Also if there's a panel short you will get these symptoms as well. Try disconnecting ribbons from tcon to panel and restart.

[nogger]

Re: Sharp LC-32D12E Standby Light Just Flashing

Hi Freakafter8

unpluggedthe flat cable from the panel at the motherboard end, same problem. Also tried holding the power & -Vol, same problem.
Graham

[nogger]

Re: Sharp LC-32D12E Standby Light Just Flashing

Forgot to mention, unplugged the cable to the inverter as well just for the hell of it , same again no fifference.

[vinceroger69]

Re: Sharp LC-32D12E Standby Light Just Flashing

did you see my edit post 8

[tom66]

Re: Sharp LC-32D12E Standby Light Just Flashing

The advice for clearing the errors only applies for genuine Sharp sets; these are Vestel sets so it doesn't apply.

[vinceroger69]

Re: Sharp LC-32D12E Standby Light Just Flashing

ah did not know that good job your up to speed on these vestel s psu

[nogger]

Re: Sharp LC-32D12E Standby Light Just Flashing

Thnks Vince, just tried that & same same. When you say Input select i take it you mean TV/AV as it is marked on the button (next to the power switch).

Graham

[tom66]

Re: Sharp LC-32D12E Standby Light Just Flashing

Well, looking at the schematic, STBY should be HIGH to turn VCC_3V3_ON high. It's low though and the output's still high. However, it appears that there may be jumper links to bypass the switching.

I'm thinking VCC_3V3 is a standby voltage - so it looks like it's switching correctly.

[vinceroger69]

Re: Sharp LC-32D12E Standby Light Just Flashing

Thnks Vince, just tried that & same same. When you say Input select i take it you mean TV/AV as it is marked on the button (next to the power switch).

Graham

not sure myself ? copied from another site is there a select or ok key tom66 said this wont work as not a genuine sharp set
http://www.tv.quuq.org/forum/index.p...e;topic=6583.0
same psu