google.com, pub-1990720073119592, DIRECT, f08c47fec0942fa0 FIXLEDTV: Repairing LG 17LX1R LCD Television Power board

Tuesday, December 31, 2013

Repairing LG 17LX1R LCD Television Power board


Here is a decent looking LCD TV/monitor that would no longer turn on. I expected a few capacitors etc. that needed to be replaced. In this case, it was a single diode at the cost of 29cents and a bit of over 1 hour of labor. It also shows the importance of a good visual inspection. A new power board for this TV would have cost somewhere around 100$




Step 1 — Power board 






  • Here is the LG 17LX1R that will no longer turn on.







  • Remove the cover from the stand by







    • simply pressing down on the two tabs. The cover will come off easily









  • Remove the four screws that hold the stand assembly to the chassis.



Image #1


Step 2 






  • Here again are the four screws to be removed from the stand.







  • Remove the eight Phillips screws that hold the back to the chassis. Once the screws are removed, the back will simply snap off. No excessive force or tools are needed.







  • This is the view with the back off. Time to remove the metal shield. It is fastened with six Phillips screws.



Image #3


Step 3 






  • Remove the two on the left







  • Remove the two on the right.







  • Remove the two on top.







    • Once the six screws are removed the shield can be lifted away easy.





Image #1


Step 4 






  • After the shield is removed, the power board as well as the main board are immediately visible.







    • Power Board







    • Main Board







    • Fuse







    • Check all capacitors for blown tops and/or leakage.









  • Here is the importance of a good visual inspection. Brown discoloration around Diode D102 is good evidence of a short circuit, possible blown component.







  • Disconnect all connectors from the power board







    • Remove the four screws that mount the power board to the chassis.







Image #1



Image #2









Step 5 






  • Chassis with the power board removed







  • Discoloration of the back side of the power board points again to a bad diode.







  • Unsolder the diode from the power board







    • Replacement diode










Image #3











Image #3





Image #2


Step 6 






  • Here is the unsoldered diode. description on the diode reads LT526 IN4007. Arranged to purchase at $0.29 per diode.







  • Solder the new diode onto the power board. Use a pair of tweezers or hemostat to hold the diode in place while soldering.







  • Diode replaced, clean the board with isopropyl alcohol to get rid of any debris or old flux.



Image #2



Image #1

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