Sharp AQUOS tv model LC-60LE633U

[DAVEMAC02]

Hi All! This my first posting. I have a dead Sharp AQUOS tv model LC-60LE633U. I get 2 long flashes followed by 5 short rapid flashes on the front power light. I checked power supply voltages for those I could access and saw the 12 volt dc supply measured 7.35 volts instead of 12vdc. I isolated the 12vdc supply pin from where it went to Main Logic board. The voltage was still 7.35vdc so I don't think Main board is draining missing voltage. I traced the 12vdc power from a Low Voltage Dropout Regulator (LVDR). I plan to replace the LVDR and go from there. The power supply initially supplies voltages but they all drop back to 0 after 5 short rapid flashes start. Has anyone seen this issue with this model Sharp tv? Thanks for any advice for further checking.

[R_J]

Re: Sharp AQUOS tv model LC-60LE633U

Have you tried disconecting the t-con board? 2 long, 5 short blinks can be t-con or panel problem. You can also do a model search as there are a few similar threads

[budm]

Re: Sharp AQUOS tv model LC-60LE633U

Hi All! This my first posting. I have a dead Sharp AQUOS tv model LC-60LE633U. I get 2 long flashes followed by 5 short rapid flashes on the front power light. I checked power supply voltages for those I could access and saw the 12 volt dc supply measured 7.35 volts instead of 12vdc. I isolated the 12vdc supply pin from where it went to Main Logic board. The voltage was still 7.35vdc so I don't think Main board is draining missing voltage. I traced the 12vdc power from a Low Voltage Dropout Regulator (LVDR). I plan to replace the LVDR and go from there. The power supply initially supplies voltages but they all drop back to 0 after 5 short rapid flashes start. Has anyone seen this issue with this model Sharp tv? Thanks for any advice for further checking.

Are you talking about the PANEL12V output of 7.35V? There is common failure of 4-pin switched 12V LDO, P/N KIA78Rxx.

[DAVEMAC02]

Re: Sharp AQUOS tv model LC-60LE633U

R_J, thanks for the suggestion. I have not disconnected the t-con board. Do I disconnect the ribbon cables or just the two small wiring cables coming from the Main Logic board? I will disconnect the t-con board when I hear back from you. Thanks again!!

[DAVEMAC02]

Re: Sharp AQUOS tv model LC-60LE633U

Budm, you are spot on. The device is a LDO with 4 leads. Lead 1 voltage in, lead 2 voltage out, lead 3 Gnd, and lead 4 Control. I have the 13 volt input but not the correct output. I also read 2.72vdc on control lead. Your LC/LED Primer on these tv power supplies is outstanding. Where would I read the 24vdc on the power supply connector going to the Main Logic board? When I replace the LDO, this may cure the problem...I'll let you know. Thanks for the guidance.

[R_J]

Re: Sharp AQUOS tv model LC-60LE633U

If the ldvr has been a problem as budm suggests, replace it first, If there is still an issue, I would disconect the wire cables first, if that allows the voltage to stay up, then reconnect them and disconnect the flat ribbons going to the panel.
Likely the lvdr will fix it. the control on pin requires min 2 volts and you have 2.7 so it should be on

[DAVEMAC02]

Re: Sharp AQUOS tv model LC-60LE633U

R_J, thanks for the suggestion. I will replace LDO and then check operation. Any idea on how much thermal grease/paste to use between heat sink and LDO device? I understand grease or paste is not so much for insulation but to eliminate air spaces that would decrease efficiency of heat dissipation...is this correct? Thanks

[R_J]

Re: Sharp AQUOS tv model LC-60LE633U

You need a minimal amount, it is there to help heat tranfer to the heatsink, any extra will only just squeeze out

[budwich]

Re: Sharp AQUOS tv model LC-60LE633U

Before you go to far, you need to follow the suggestion about disconnecting the cables as there may be loading "downstream" that is causing "poor voltage" and thus replacing the regulator will solve nothing.

[DAVEMAC02]

Re: Sharp AQUOS tv model LC-60LE633U

Budwich, good point! It will only take a few minutes to make this check before proceeding. Thanks.