LG 26LC7DC | 26" LCD
Symptoms:
TV had trouble turning on. Over the following weeks, it would take longer and longer to power up. Finally, it would not power up at all, and only the power LED would blink (green/red) when the power button was pushed.
Diagnosis:
Because this particular set had power issues that worsened over time, my first thought was capacitors. It's like when the batteries start to get low in your drill or what have you. Opening the set up showed that this was, indeed, the case.
Solution:
Replace the capacitors! This reminds me that I need to do a video tutorial on this (or at the very least, find a good one on YouTube).
Anyway, if you are comfortable with a soldering iron, this will be a quick job for you! In my case, the power supply had five (5) busted caps including the following: 1x 3300uF 10V, 1x 2200uF 10V, 3x 680uF 35V.
After carefully replacing each with a comparable part, The TV worked great! My parts list included: 1x 3300uF 16V, 1x 2200uF 16V, 3x 680uF 35V.
Good luck, and if you find that you have a query, please get a hold of me at crkalinowski@gmail.com.
Friday, January 31, 2014
Friday, January 24, 2014
Repair Journal | Samsung PN43D450A2FXZA (N102)
Samsung PN43D450A2FXZA (N102) | 43" PDP
Symptoms:
TV will not turn on. Relay clicks repeatedly on power-up attempts.
Diagnostics:
Test critical voltages.
Panel sticker rated voltages:
VS: 205V
VA: 58V
Vsc: -180V
With everything hooked up:
VS: 0.3V-0.5V
VA: 0V
Vsc: -- (not measured)
Remove power connector (X and Y-MAIN):
VS: 205V (spike and shutdown)
VA: 55V (spike and shutdown)
Vsc: -- (not measured)
-NOTE-
The reason the voltage spikes and disappears quickly is because the circuit is not complete (i.e. the boards needed for operation are disconnected from the power circuit) and the TV goes into shutdown immediately. When you plug in the power cord with these boards disconnected, you can have your DMM probes on the VS and VA test points beforehand. This allows you to see if the PSU is operating correctly. Seeing the correct voltages at startup confirms that the short is elsewhere.
Continuity tests (power off, X and Y-MAIN disconnected)
Set your DMM to continuity mode and place one probe on the chassis and another at each of the following test points. If there is continuity (i.e. there is a tone that sounds when my DMM detects a complete circuit), you have a short at the tested point.
VS: OK
VA: OK
Vsc: OK
XS_E: SHORT
XS_C: SHORT
XG_E: SHORT
XG_C: SHORT
The short on the X-MAIN board indicates that this is the problem board.
Solution:
Replace the X-MAIN board. It is most certainly bad. While you're at it, get a hold of a LOGIC BOARD (the green one just south of the PSU) and replace it as well. Don't ask me why, but this vintage of 43" Samsung Plasma (the "D" in the model number "PNxxDxxx" indicates it was manufactured in 2011) seems to be a victim of this failure often. If you have a shorted X-MAIN, there is a 70-80% chance that the LOGIC is also shot.
Be sure that you immediately upgrade the firmware on this television after installing the new LOGIC and X-MAIN boards.
-PROTIP- Now, if you were working with a "PN51Dxxx" (the 51" plasma model from this year), it is more often the Y-MAIN and X-MAIN. You would get a short on the Vsc point during continuity testing if the Y-MAIN was bad.
Pictures will be available soon!
Symptoms:
TV will not turn on. Relay clicks repeatedly on power-up attempts.
Diagnostics:
Test critical voltages.
Panel sticker rated voltages:
VS: 205V
VA: 58V
Vsc: -180V
With everything hooked up:
VS: 0.3V-0.5V
VA: 0V
Vsc: -- (not measured)
Remove power connector (X and Y-MAIN):
VS: 205V (spike and shutdown)
VA: 55V (spike and shutdown)
Vsc: -- (not measured)
-NOTE-
The reason the voltage spikes and disappears quickly is because the circuit is not complete (i.e. the boards needed for operation are disconnected from the power circuit) and the TV goes into shutdown immediately. When you plug in the power cord with these boards disconnected, you can have your DMM probes on the VS and VA test points beforehand. This allows you to see if the PSU is operating correctly. Seeing the correct voltages at startup confirms that the short is elsewhere.
Continuity tests (power off, X and Y-MAIN disconnected)
Set your DMM to continuity mode and place one probe on the chassis and another at each of the following test points. If there is continuity (i.e. there is a tone that sounds when my DMM detects a complete circuit), you have a short at the tested point.
VS: OK
VA: OK
Vsc: OK
XS_E: SHORT
XS_C: SHORT
XG_E: SHORT
XG_C: SHORT
The short on the X-MAIN board indicates that this is the problem board.
Solution:
Replace the X-MAIN board. It is most certainly bad. While you're at it, get a hold of a LOGIC BOARD (the green one just south of the PSU) and replace it as well. Don't ask me why, but this vintage of 43" Samsung Plasma (the "D" in the model number "PNxxDxxx" indicates it was manufactured in 2011) seems to be a victim of this failure often. If you have a shorted X-MAIN, there is a 70-80% chance that the LOGIC is also shot.
Be sure that you immediately upgrade the firmware on this television after installing the new LOGIC and X-MAIN boards.
-PROTIP- Now, if you were working with a "PN51Dxxx" (the 51" plasma model from this year), it is more often the Y-MAIN and X-MAIN. You would get a short on the Vsc point during continuity testing if the Y-MAIN was bad.
Pictures will be available soon!
Repair Journal | Toshiba 32SL400U
Toshiba 32SL400U | 32" LED LCD
SYMPTOMS: TV fully functional, with the exception of the speaker(s) making a "clicking" sound. Audio comes through periodically.
DIAGNOSTICS: Opened set for inspection. When powered on, clicking continued. When speakers were removed from their mount points, the clicking stopped. A simple "touch-test" (i.e. making contact between the speaker terminal and the panel assembly) showed that the source of the clicking was essentially a short between the aforementioned components.
SOLUTION: Bend speaker terminals up and away from panel slightly and use electrical tape to insulate area behind speakers.
Instructions. You must remove all back cover screws (don't forget the one near the inputs) and base stand screws. Once you've accomplished this, carefully pry up the back cover, and thread the cord through the hole in the back. With the cover removed, inspect the speaker assemblies. If you wish, turn the set on with an input connected so you can test the audio. If you can fiddle with the speakers and recreate the clicking sounds, you've nailed your problem. Move the speaker assemblies out of the way and place a strip of electrical tape on the panel assembly (you can see the red tape through the slots in the picture) and bend the terminals (gently) in the direction away from the panel assembly before reinstalling. Carefully reassemble the set and enjoy! You've just fixed your audio for free.
SYMPTOMS: TV fully functional, with the exception of the speaker(s) making a "clicking" sound. Audio comes through periodically.
DIAGNOSTICS: Opened set for inspection. When powered on, clicking continued. When speakers were removed from their mount points, the clicking stopped. A simple "touch-test" (i.e. making contact between the speaker terminal and the panel assembly) showed that the source of the clicking was essentially a short between the aforementioned components.
SOLUTION: Bend speaker terminals up and away from panel slightly and use electrical tape to insulate area behind speakers.
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| Screw and speaker locations. |
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