sharp 50-lb371u leds problems

[robert phelps]

Re: sharp 50-lb371u leds problems

thanks but shouldnt the logic board shut down the psu

[robert phelps]

Re: sharp 50-lb371u leds problems

ps_on is still there when you power set off psu is off until you first power the set on , im sorry after you first plug it in after that it never goes off unless you unplug the logic board then it stops

[robert phelps]

Re: sharp 50-lb371u leds problems

ps_on and dim signals come from the logic board right

[budm]

Re: sharp 50-lb371u leds problems

ps_on and dim signals come from the logic board right

Main board sends out those control signals.
When TV is in standby, the PS-ON, and BL-ON (O/F) should be <1VDC, then they should go up to >2VDC when TV is turned on, this is applied to ACTIVE High logic.
Basically though, those signals should change state when TV is turned on and when turned off.
Read my Basic troubleshooting link.

[robert phelps]

Re: sharp 50-lb371u leds problems

dick barton, i think you have hit on it why these sets are bad about the leds. 2 circuits one controls 22 leds and the other does 44 not the same. im going to try and rewire the leds so there are 33 on both circuits

[budm]

Re: sharp 50-lb371u leds problems

"when you power the set off the ps_on stays at 3.34v and the dim stays at 3.09 volts. the o/f does go to 0volts." That is not normal for PS-ON, the power supply is stuck on.

[budm]

Re: sharp 50-lb371u leds problems

dick barton, i think you have hit on it why these sets are bad about the leds. 2 circuits one controls 22 leds and the other does 44 not the same. im going to try and rewire the leds so there are 33 on both circuits

If it was designed that way then do not change it since it will trip the protection circuit. Are you sure they are not equally driven?
Need to look up the spec of the LCD panel, TVP: TPT500J1-HVNO7.U

Are these the same LED strips?
http://www.shopjimmy.com/vizio-tpt50...d-e500i-a1.htm

How many does it have in your panel?

[robert phelps]

Re: sharp 50-lb371u leds problems

the only thing is when you first plug the set in the psu is not on it only after its turned on that it stay on as far as the leds go everything else goes off

[budm]

Re: sharp 50-lb371u leds problems

the only thing is when you first plug the set in the psu is not on it only after its turned on that it stay on as far as the leds go everything else goes off

It sound like the processor got stuck.

[robert phelps]

Re: sharp 50-lb371u leds problems

im sorry i just dont know what the dim does also

[budm]

Re: sharp 50-lb371u leds problems

Dim is the control to dim down the backlights, just light light dimmer in your house.

[robert phelps]

Re: sharp 50-lb371u leds problems

budm your post 27 no those are not the led strips they are 500tt65/500tt66v1

[robert phelps]

Re: sharp 50-lb371u leds problems

what is real funny is that the leds that are on led 2 which is the 2 strips with 22 leds where dimmer the the other 4 sets of leds before they died again

[robert phelps]

Re: sharp 50-lb371u leds problems

if the psu is stuck on wouldnt it stay on after you unpluged the logic board, it still would have 110v going to it

[budm]

Re: sharp 50-lb371u leds problems

If the power supply board has pull-up resistors on the PS-ON and BL-ON (O/F) pin for running power supply board self test, then the power supply will be fully on.
So you can test that by running the power supply board by itself and check the DCV on the PS-ON pin to see what you have, and the DCV between the two legs of the main filter caps (either one of them) laying on the side will have close to 400 VDC if the power supply is ON.

[robert phelps]

Re: sharp 50-lb371u leds problems

the ps_on has 0 volts the 2 large caps have 377 volts on each nothing hooked to psu

[budm]

Re: sharp 50-lb371u leds problems

the ps_on has 0 volts the 2 large caps have 377 volts on each nothing hooked to psu

Something is not making sense right now.

Your earlier post:
when you power the set up ps_on goes to 3.34, the dim goes to 3.09 and the o/f goes to 3.32. when you power the set off the ps_on stays at 3.34v and the dim stays at 3.09 volts. the o/f does go to 0volts.

But right now you have PS_ON = 0 V and you have boosted Voltage of 377VDC.

It sounds like ACTIVE LOW, so hook up the power supply back to the main board and check the PS_ON, it should be at 3.34 as your report above, then check the DCV at the main filter cap again to see what you have, it should be around 160 DCV with PS-ON of 3.34VDC.

[robert phelps]

Re: sharp 50-lb371u leds problems

sorry life got in the way im going to try this now thanks

[robert phelps]

Re: sharp 50-lb371u leds problems

when the set is pluged in there is ps on is 0 main caps are 166v. power on ps on is 3.3 and mains caps are 388v. set powered off , no inmage on screen ps on is still 3.3 and main caps both have 390v on them

[robert phelps]

Re: sharp 50-lb371u leds problems

the leds for this set are from strips 500tt66v1/ 500tt65v1 how do i find these leds by what number. im so new to this im lost thanks