SHARP LC46E77UN just power light on

[budm]

Re: SHARP LC46E77UN just power light on

Those two resistors are being used as protection in case IC9604 Vin pin or CE pin, or the filter cap is shorted to GND. 5V to run the IC is fed through those two resistors. I would check the resistance between gnd and Vin pin.

[kgavionics]

Re: SHARP LC46E77UN just power light on

Those two resistors are being used as protection in case IC9604 Vin pin or CE pin, or the filter cap is shorted to GND. 5V to run the IC is fed through those two resistors. I would check the resistance between gnd and Vin pin.

the resistance between Vin and ground is around 1Mohm.

[budm]

Re: SHARP LC46E77UN just power light on

If it is really 1 M Ohms then I cannot see you can have Over 4V on the basically bad resistors unless the Vin pin has gone open circuit after taking out those two 1 Ohm resistors, it has to be quite high current to blow open 1 Ohm 1/2W resistors.
If Vin pin or the cap was shorted to GND in the beginning, that means you will have 5V/2 Ohms = 2.5A of current flow through the resistors.
2.5A * 5V = 12.5 Watts so each resistor will try to dissipate 6.25W each.
So may be the circuit inside the IC has gone open circuit or high resistance now.

[kgavionics]

Re: SHARP LC46E77UN just power light on

thanks for the heads up budm
if i put my multi meter leads across the resistor R9630 it reads 250kohm ( weird right!!) i don't see any component in parallel with it that might give me a reading error according to the schematic.I don't know really what happened to a 1 ohm resitor to become a 250 kohm, but my point was that the 5V coming to the Vin pin was almost dropped across that R9630. Now, whether that IC is open or not, will find out tomorrow after i replace this resistor.

[budm]

Re: SHARP LC46E77UN just power light on

It is just the Ohm's law of thing, something bad had happened, too much current flow some how.

[kgavionics]

Re: SHARP LC46E77UN just power light on

It is just the Ohm's law of thing, something bad had happened, too much current flow some how.

yeah!! you're right!! something really nasty had happened to that resistor

[kgavionics]

Re: SHARP LC46E77UN just power light on

Bingo!!problem fixed.it was the resistor like i predicted before.replaced it and tv is working like a charm.

[budm]

Re: SHARP LC46E77UN just power light on

Glad to hear, but I would keep close eyes in that section, the resistor went open circuit for reason.

[kgavionics]

Re: SHARP LC46E77UN just power light on

Glad to hear, but I would keep close eyes in that section, the resistor went open circuit for reason.

yeah! you're right Budm.it's a little bit weird, because the 2 resistors are in series.A high current would blow them open at the same time, but only one resistor went open.
any ways i'll keep an eye on it.
I want to thank you.you helped me a lot to fix that problem.

[road7]

Re: SHARP LC46E77UN just power light on

i want free pdf service manual lc-52se94u ... nothing found free !! thanks help me :-)

[road7]

Re: SHARP LC46E77UN just power light on

same problem resistors .. but i don't have schéma for resistors how many
ohm ..

[budm]

Re: SHARP LC46E77UN just power light on

same problem resistors .. but i don't have schéma for resistors how many
ohm ..

See Post #40 or read the whole thread.

[budm]

Re: SHARP LC46E77UN just power light on

i want free pdf service manual lc-52se94u ... nothing found free !! thanks help me :-)

http://elektrotanya.com/?q=showresul...oria=&kat2=all

[road7]

Re: SHARP LC46E77UN just power light on

ok but not working elektrotanya !! do you have other site free download lc-52se94u or 46se94u 65se94u service manual

schéma number 40 it's not same .. don't have ic9604

[budm]

Re: SHARP LC46E77UN just power light on

What do you mean not working? That site is used by many people here.
lc-52se94u
http://elektrotanya.com/?q=showresul...oria=&kat2=all

What model are you working on? This thread is for SHARP LC46E77UN.

[road7]

Re: SHARP LC46E77UN just power light on

work model lc-52se94u

[budm]

Re: SHARP LC46E77UN just power light on

work model lc-52se94u

See post 55 for download.

[road7]

Re: SHARP LC46E77UN just power light on

ok thanks budm perfect download :-) .. problem voltage is terrible section ic9605 ic9602 ic9641 .. schéma page 91