sceptre x505bv-fmqr have sound, no picture

[supafly]

Hello all. I did the flashlight test and can see menu screen thru black screen. Red standby light works and blue light stays on when tv is turned on. I read the other thread for this tv but a little confused on where one of the voltage readings were taken. Heres the voltages i get from the three sets of pins on power supply board with tv on:

5v. 5.14
5v. 5.14
Ps on. 4.55
+5vsb. 5.14
+5. 5.14
+5 5.14
12v 12.31
12v 12.31

+24. 24.9
+24. 24.9

+12. 12.31
+12. 12.31

Blon. 4.68
Adj. 2.92


Hopefully its the main board or power supply so i dont have to mess with led.
Anywho im uploading picture of the 2 boards. Any other readings just let me know.
Thanx

[dick_barton]

Re: sceptre x505bv-fmqr have sound, no picture

Can you name the connector, the legend and then the voltage read
Con2 has 13 pins of which some are not used. It's helpful to other who may have a similar problem to then use as a guide.

Con2
Pin1 GND, NC (No connection)
Pin2 GND, NC
Pin3 +5V, +5V
.
.
.
Pin12 +12V, +12V
Pin13 +12V, NC
etc
and repeat for Con 3, 4 & Con 10 (with the red and black wire going to the leds)

Suspect a led fault at this stage.

[dick_barton]

Re: sceptre x505bv-fmqr have sound, no picture

Have a read through this thread for more help.

[supafly]

Re: sceptre x505bv-fmqr have sound, no picture

Thank you for repliies dick barton. The thread you linked to is th one i read. The part number on power supply in that thread is slightly different than mine. Dont know if that matters. Im new to this tv stuff. I will reformat my voltages posted. Again thank you for replies.

[Andrew F. Ali]

Re: sceptre x505bv-fmqr have sound, no picture

I'm sorry to say but you could have a backlight problem. With the TV OFF set your DMM on VDC if it is an auto-ranging type or on 750VDc if it is a manual adjust, like mine. Then connect the RED DMM lead to the red wire on CON 10 and the BLACK lead to the chassis GND (any bare metal of the frame/chassis). Turn ON the TV and report what you observe. Repeat the same with the RED DMM lead to the black wire on CON 10 and the BLACK lead to the chassis GND. Turn ON the TV and report what you observe.

[supafly]

Re: sceptre x505bv-fmqr have sound, no picture

Thank you andrew. I did both steps. Red lead to red wire black lead to chassis no change on meter. 2nd step resulted in a -350 and over 10 seconds went to zero. My Meter only goes to 600vdc though.

[supafly]

Re: sceptre x505bv-fmqr have sound, no picture

Also i took those 2 readings at the power supply board. Should i do it again at the mainboard also?

[dick_barton]

Re: sceptre x505bv-fmqr have sound, no picture

Also i took those 2 readings at the power supply board. Should i do it again at the mainboard also?

Measure the voltage between the red wire and chassis at switch on and record the maximum and minimum voltages.
Repeat the measurement again but this time between the black wire and chassis.

[supafly]

Re: sceptre x505bv-fmqr have sound, no picture

I thought i did that and gave results above.
I just did it again and voltage between red wire and chassis is max 0 and min 0.
Voltage between black wire and chassis is max -352 and min is 0.
Am i missing something?

[dick_barton]

Re: sceptre x505bv-fmqr have sound, no picture

Sorry, you did. I misread your reply. It looks as though you have faulty led(s).

[supafly]

Re: sceptre x505bv-fmqr have sound, no picture

Ahhh ok cool so i just go thru the leds and replace the bad ones and im good?

[dick_barton]

Re: sceptre x505bv-fmqr have sound, no picture

As long as there are not too many faulty on each strip. If there are two or more per strip it may be worth considering replacing the strip.

[supafly]

Re: sceptre x505bv-fmqr have sound, no picture

Thank you very much sir

[supafly]

Re: sceptre x505bv-fmqr have sound, no picture

Thank you very much sir

[Andrew F. Ali]

Re: sceptre x505bv-fmqr have sound, no picture

As long as there are not too many faulty on each strip. If there are two or more per strip it may be worth considering replacing the strip.

I have found that if you do not want to have repeat failure, replace ALL the LED strips with NEW strips. Replacing the LED individually works too but the seemingly good ones may be weakened and so Backlight failure re-occur.
Just be extremely careful handling the very brittle, thin glass screen, they crack or break easily. You may want to invest in some glass handling suction/vacuum lifts to make it easier for you.

[dick_barton]

Re: sceptre x505bv-fmqr have sound, no picture

+1
Something very worth considering. It would be a pity after going through the efforts of replacing individual leds that others start failing.
Ultimately I suppose it comes down to how expensive replacement strip are.

[supafly]

Re: sceptre x505bv-fmqr have sound, no picture

I will take the advice you folks have given me and remove the strips. Ill get the panel and strip numbers and star searching for a good source. Thank you very much for all the help and ill keep u posted even if i lose my mind and throw it through the dining room window.

[Andrew F. Ali]

Re: sceptre x505bv-fmqr have sound, no picture

ill keep u posted even if i lose my mind and throw it through the dining room window.

A sense of humor is important in this field as some of these circuits and repairs can get you really crazy. Go for it, you will be successful.