Samsung LN55C630 Sound ok, No backlight

[alfredomfr1]

Re: Samsung LN55C630 Sound ok, No backlight

I did this measures before, check post # 8

[budm]

Re: Samsung LN55C630 Sound ok, No backlight

Black point of the multimeter connected to the chassis of the tv and taking measure with the red point on FAN7530, all pins read less than 0.1v

OK, you are making Voltage measurement in the primary side of the circuit so you have to use the negative leg of the main filter cap as the ground ref point for the meter.
Please make the DC voltage measurement of all the pin of FAN7530.
Then check the resistance between the Ground pin against all the other pin and report the resistance readings, please make sure to report if the reading is in Ohm, K Ohm, or M Ohm.

[alfredomfr1]

Re: Samsung LN55C630 Sound ok, No backlight

Resistance GND (pin 6) with TV off - pin 1: 38.4k; pin 2: 47.1k; pin 3: 11m; pin 4: 0.5;
pin 5: 19.65k; pin 7: 4.64k; pin 8: start 2m but slowly going down.

Voltage: pin 1: 1.06v; pin 2: 0.1v; pin 3: 0v; pin 4: 0.17v; pin 5: 0.007;
pin 6: 0v; pin 7: 0v; pin 8: 15v

[budm]

Re: Samsung LN55C630 Sound ok, No backlight

It looks like the FAN7530 is putting out any drive signal on pin 7 even though it has high enough VCC (15VDC) to run the IC.

[alfredomfr1]

Re: Samsung LN55C630 Sound ok, No backlight

FAN7530 defective?

[budm]

Re: Samsung LN55C630 Sound ok, No backlight

More likely.

[alfredomfr1]

Re: Samsung LN55C630 Sound ok, No backlight

I will order the FAN7530. thanks for your help budm

[budm]

Re: Samsung LN55C630 Sound ok, No backlight

Some time you just have to try new IC, there is no way to 100% test the IC unless you make the test bed for functioning test of the IC.