Riddled TV Repair Forum
Service Menu and Manual Schematics
 
   
 FAQFAQ   SearchSearch   RegisterRegister 
   Log inLog in 
LG 50PY2DR-UA Won't Turn On    
Post new topic   Reply to topic    Riddled TV Repair Forum Index -> TV Repair
 
Author Message
Mthrboard



Joined: 10 Oct 2009
Posts: 3
Location: St. Cloud, MN

PostPosted: Sat Oct 10, 2009 11:07 pm    Post subject: LG 50PY2DR-UA Won't Turn On Reply with quote

Hello everyone. I just inherited an LG 50PY2DR-UA 50" Plasma TV from my mom that isn't working. According to her, it stopped displaying video but still played audio, but I can't even get it to do that. When I plug it in, the light on the front glows red, I hear the click of a relay or something on the power board, LED170 lights up red and LED901 lights up green on the digital board. Two seconds later, D15 and D17 light green on the control board, then another second or two later, I hear another click and everything shuts off. If I press the power switch, the LED up front switches from red to orange and flashes 6 times before glowing solid orange. Pressing it again switches the LED back to red (and then back to flashing then solid orange), but the clicking and LEDs in the back don't turn on again.

So far I've examined every capacitor I can see with a flash light and magnifying glass, and found no bulged capacitors. I reseated all the cables and other connectors from board to board. I've tried audio and video sources on all inputs. The three fuses I was able to find (one on the power board, two on the control board) all are OK. I'm not really sure where to go from here. Computers are more my forte, I just like watching televisions. But at the same time, a lot of these newer TVs basically have computers inside them anyway, especially this one with the built-in DVR, so I figure it's about time to learn how to fix these too.

Here are the TV details: Model 50PY2DR-UA AUSLYAD, Chassis # AF-05FA, Manufactured June 06, serial 606KCQX1G164. Any help would be greatly appreciated. Thanks in advance.
Google

PostPost subject: Advertisement

JTS1957



Joined: 21 Jan 2009
Posts: 2395
Location: Far, Far Away

PostPosted: Sun Oct 11, 2009 3:42 am    Post subject: Reply with quote

Mthrboard wrote:
So far I've examined every capacitor I can see with a flash light and magnifying glass, and found no bulged capacitors.
You've checked them for physical and visible defects. Now check them for "VALUE" and excessive Equivalent Series resistance ("ESR.") How about Dielectric Absorption ("DA") and Excess "Leakage." If every examined capacitor passes ALL tests - Then it's "GOOD." Smile
Jesse Mack



Joined: 22 May 2008
Posts: 600
Location: The Last Frontier

PostPosted: Mon Oct 12, 2009 11:59 am    Post subject: Reply with quote

Your symptom exactly matches a bad Y-SUS pcb assy. Check the fuses (GMA type ceramic fuses that are white) on the Y-SUS pcb (large board on left side of set when facing the back)

The most typical failure is a shorted IPM IC (the large block cooled by a heat sink)

If open fuse replace Y-SUS pcb assy

Jesse
Mthrboard



Joined: 10 Oct 2009
Posts: 3
Location: St. Cloud, MN

PostPosted: Sun Oct 25, 2009 4:07 pm    Post subject: Reply with quote

I replaced the Y-SUS board. Now, it powers up, the panel turns on, but there is no video, only a sparkling glittery effect in the center of the screen, with a couple rows of red pixels at the top edge of the screen. When I hit the power switch, the power LED on the front flashes orange 4x, then green 4x, then glows solid green. The rest of the indicators up front turn on as well. It responds to commands to change input sources, but I still get nothing on any source. After it's been on for a couple minutes, the glittery effect mostly goes away, with only a few blinking red pixels. Can the Y-SUS board damage other components when it goes out?
Jesse Mack



Joined: 22 May 2008
Posts: 600
Location: The Last Frontier

PostPosted: Mon Oct 26, 2009 5:27 pm    Post subject: Reply with quote

Many times the failure of the Y-SUS board is attributable to a failed upper or lower Y-Buffer assy. Examine the IC's carefully (with a magnifying glass looking for a pinhole failure on one of the chips. Also, check the DC levels on the power supply board and make sure they match the voltages printed on the sticker of the panel itself.
Another thing. Did you get an exact replacement part? It can make a large difference. Also check to make sure all of the connectors have been reinstalled and installed correctly. It is common to forget the connector that goes on the bottom of the board and even more common to insert the flexible flat cable a little crooked or not fully inserted.

Hope this helps.

Jesse
Google

PostPost subject: Advertisement

Mthrboard



Joined: 10 Oct 2009
Posts: 3
Location: St. Cloud, MN

PostPosted: Mon Oct 26, 2009 7:12 pm    Post subject: Reply with quote

Ok, so I missed the LVDS cable, and now the panel lights up, but it's just a snowy mess. How tight are the tolerances on the supply voltages? The panel sticker says Va 60v, Vs 196v. My multimeter shows Va 58.0V, Vs 179.6V. The Y-SUS board I installed is an identical part # match for the one I pulled out (6871QYH039A)
Display posts from previous:   
Post new topic   Reply to topic    Riddled TV Repair Forum Index -> TV Repair All times are GMT - 6 Hours
Page 1 of 1

 


Disclaimer: All information provided by RiddledTV is strictly for information purposes only. Please observe all warnings displayed on your electronic
devices. This information should only be used to help diagnose work, and all service should be performed by a qualified technician.
Privacy Policy       Copyright © 2020 RiddledTV.com       Advertise on RiddedTV.com