Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

[igundwane]

Evening all .....

Joining the ranks of those shouting help .....

Vestel PSU 17PW07-2 021111 / Laurus TV or TOSHIBA 40BL702B Board, 5 red blinking lights, screen on, screen off and cycles back.

Problem with the PSU .... but which offending little items are they ? And .... can they be gotten from Maplins ...... !!

All and Any Suggestions Welcome

Picture of the Offending Item ....

[tom66]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Hah, crappy rebadged Toshiba.
Sure about 17PW20-2? That looks like a PW80 or thin LED supply to me.

[igundwane]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Well .... for £50 I thought I would take a punt on it ...... LED 42"

Nope, that is what it says on the Board

[tom66]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Looks like 17PW07-2 to me.

[igundwane]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Honest Dude, its got the twin silver heat sinks in it ....

And yes ... Me Wrong - You Right

It is the 17PW07-2 021111

[tom66]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Well, I know 17PW20.2 for all the wrong reasons. Absolutely one of the worst PSUs out there. So. Many. Problems.
Can we have a picture of the overall chassis layout? (it doesn't matter if PSU is missing for now.)

[igundwane]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

[tom66]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Schematic (the one without a dot prefix)
http://www.tgohome.com/ServiceManual...&Search=Submit

Check for 24V on connector PL306.

[igundwane]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

I shall do ... thank you for that, potential root of all evil ?

[tom66]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

If the backlight flickers/blinks on or off we need to check if the 24V is unstable, if it is then PSON needs to be checked, if PSON is unstable it is a main board fault; if PSON is stable it is a power board fault; if both are stable then BLON is checked; if BLON is stable it is an LED driver fault; if BLON is unstable it is a main board fault.

Simples.

[igundwane]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Aaah, well the screen lights up with a solid blue, no flickering or wavering.

[tom66]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Thought you said screen came on then off; I interpreted this as it lighting up then going off?

[igundwane]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

OK maybe crossed wires here, Once it goes past the 5th red blink, the screen turns on albeit for 20secs, shows a solid blue color all over, no wavers, squiggles, lines etc ... then it turns off, very soft click then the red light starts to blink again.

Is that a better description ? ....

[tom66]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

OK, so please check the 24V then, it sounds like a PSU or main board fault.

[igundwane]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

OK dude, you are going to go " grrrrr " now, I cannot find a PL306 ...... Been searching, and not a thing ...

Looking at the photo of chassis, is it :

a: top left small board
b: right board with the HDMI ports on it
c: main PSU board
d: small board bottom centre

[tom66]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Main PSU, connector going to LED driver (top left small board.)

[igundwane]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Sorry Tom, Sleep over came last night ...

However, digging around this morning, Sharp which uses a similar board has come up with this ... Any help ?

In the meantime i will go and try and find my volt meter which is buried somewhere in the house

[tom66]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Could be useful -- I think that is on the main board.

[igundwane]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

Futher to the previous, might be worth replacing the 4 x elite 1000uf 16v Caps as it seems from more reading, they may be the cause, trip to maplins

[tom66]

Re: Vestel PSU 17PW20-2 / Laurus TV or TOSHIBA 40BL702B

DO NOT use capacitors from Maplins, they are NOT suitable and in fact are worse than the original Elite in most cases.
Don't know where you live but Farnell, who sell low-esr reliable Panasonic and Rubycon, are about 5 mins drive from me.