Shard Lc-52d77x power issues

[Jeff1]

Hi

I have a lc52d77x that has dps-286ap-1 power board but has different issues to this post as tv will power up run for a minute or two then turn off (including power light with no flashing) then turn back on after a minute or two then repeat over and over. Has anyone had this issue and know what is the issue. Everything works fine on the tv when on. When it shuts down you can hear a click from back of tv.

Thanks
Jeff

[Jeff1]

Re: Shard Lc-52d77x power issues

Board number

[Jeff1]

Re: Shard Lc-52d77x power issues

Photo of rear of tv

[Jeff1]

Re: Sharp Lc-52d77x power issues

I have a lc52d77x that has dps-286ap-1 power board but has different issues to this post as tv will power up run for a minute or two then turn off (including power light with no flashing) then turn back on after a minute or two then repeat over and over. Has anyone had this issue and know what is the issue. Everything works fine on the tv when on. When it shuts down you can hear a click from back of tv.

Thanks
Jeff

Have noticed the IC7905 gets really hot and shuts down the board. If I keep this cool with vacuum cleaner it continue to work. Have also noticed there is 2 legs soldered together on the TNY264PN (IC7905) is this correct

[R_J]

Re: Shard Lc-52d77x power issues

On TNY264PN those are the source pins, 2,3,7 & 8 are connected together, That ic gives you the standby voltage. I would try replacing the two caps, C7915 & C7918 first.
You can check the standby voltage on D7918, does it change or drop down.

[Jeff1]

Re: Shard Lc-52d77x power issues

On TNY264PN those are the source pins, 2,3,7 & 8 are connected together, That ic gives you the standby voltage. I would try replacing the two caps, C7915 & C7918 first.
You can check the standby voltage on D7918, does it change or drop down.

Hi

I checked the voltage on D7918 and was holding stable at 13.2v by memory but have found a solution to the heat problem on the TNY264PN (IC7905)! I made a heat sink out of a piece of aluminium plate and bent it up to go onto the aluminium heat sink towards the bottom of the board and used a little bit of heat transfer paste between the top on TNY264PN (IC7905) and bottom of aluminium plate. Have ran tv all day now without a issue. I know it's probably not the correct fix but is working for now.