Sanyo DP42840 Cycles on and off

[shadetreetrader11]

I have a Sanyo dp42840 that cycles on and off over and over again. The backlight never gets a chance to come on.
main board is n7ae
I measured voltages on psb

PS ON = 4.98
5v = 5.02
12v = 11.81
24v = 24.05

[shadetreetrader11]

Re: Sanyo DP42840 Cycles on and off

Any help would be great

[maxvalutech]

Re: Sanyo DP42840 Cycles on and off

Do a search for your TV make and model in threads - there is at least one with similar issue.

[budm]

Re: Sanyo DP42840 Cycles on and off

I have a Sanyo dp42840 that cycles on and off over and over again. The backlight never gets a chance to come on.
main board is n7ae
I measured voltages on psb

PS ON = 4.98
5v = 5.02
12v = 11.81
24v = 24.05

So all those Voltages stay at the same values but the TV is cycling ON and OFF?

[shadetreetrader11]

Re: Sanyo DP42840 Cycles on and off

No, the voltages cycle on and off with the click of the power supply. The only voltage that never changes is the best 5vsb.

[shadetreetrader11]

Re: Sanyo DP42840 Cycles on and off

I'm at work at the moment so this is just from memory. But I did check the pins 48 and I think it was pin 23 of the IC on the main board and they both have 5 v on v them. Fail safe circuit.

[shadetreetrader11]

Re: Sanyo DP42840 Cycles on and off

Any advice on how to check the backlights?

[budm]

Re: Sanyo DP42840 Cycles on and off

Disconnect the cable to the inverter board to see what happen.
Since the PS-ON is generated by the main board, then the main board some how is not sending steady ON command so the power supply is just going on and off due to ps-on cycling.

[shadetreetrader11]

Re: Sanyo DP42840 Cycles on and off

Thanks BudM. I just unplugged the cable running to the inverter board and there is no change.

[Hawkpar]

Re: Sanyo DP42840 Cycles on and off

My friend has a Sanyo DP42840. Turn it on and I get the green LED for a few seconds and it cuts off. I checked the power fail lines and it is not detecting a failure. I don't have prints. No backlight. However, when I remove connector K8L and turn it on, I get backlight, but the unit still shuts off after a few seconds. Any ideas or suggestions?

[Hawkpar]

Re: Sanyo DP42840 Cycles on and off

K8L from the main Board.