Insignia NS-42P650A11 - click, click, off - shorted IGBT

[ngth82]

Good afternoon all -

I picked up an Insignia NS-42P650A11 (MFG April 2011).

I have a feeling everyone is going to tell me to either: junk it, or buy a new Y-sus, Y-buffer and X-sus boards to do a complete swap (which is a bad return on investment in my case)

This is what I know:

• Main: BN96-14887A V1000.3
• T-Con: PBA: LJ92-01708A, PCB: LJ41-08392A
• Power board: BN44-00329A, 42" PSPF301501A
• Y-sus: 42U2P_Y-MAIN
• Y-buff: 42U2P_YB, PBA # LJ92-01739A, PCB # LJ41-08594A
• X-sus: 42U2P_XM(1 layer),
• Panel: Samsung S42AX-YD13

• The Y-sus makes a popping noise (note, not clicking) - a popping noise - when you plugin the unit. I see that the high voltage 330pF 1kV cap at location C5008 has destroyed itself.
• I replaced the high voltage cap with an equivalent part. This did not fix the TV.
• I disconnected all of the boards. The main power supply board correctly generates Vs (211V) and Va (54V). The power supply board goes into protection mode since the X/Y boards are not hooked up. I do see the Vs and Va rails ramp momentarily to their target voltages. So, that appears to be okay.
• If I ONLY add the Y-sus board, the TV tries to turn on twice (?), but then shuts down again.
• If I add the X-sus board to this, the TV tries to turn on twice (?), but then shuts down again. (same behavior as with Y-sus only)
• I tested the Y-buffer for shorts - no short that i can find through each of the ICs.
• I'm not hooking up the Y-buffer to the equation since the X-sus and Y-sus are suspect.
• I see that the X-sus has two IGBTs that are dead short (they are marked XG - Q4007, and XS - Q4001).

Is it even worth swapping out the IGBTs on the X-sus board?
Should the TV stay on if I have the Y-buffer and X-sus disconnected?

Thanks!
-Thomas

[ivtec]

Re: Insignia NS-42P650A11 - click, click, off - shorted IGBT

Good afternoon all -

I picked up an Insignia NS-42P650A11 (MFG April 2011).

I have a feeling everyone is going to tell me to either: junk it, or buy a new Y-sus, Y-buffer and X-sus boards to do a complete swap (which is a bad return on investment in my case)

This is what I know:

• Main: BN96-14887A V1000.3
• T-Con: PBA: LJ92-01708A, PCB: LJ41-08392A
• Power board: BN44-00329A, 42" PSPF301501A
• Y-sus: 42U2P_Y-MAIN
• Y-buff: 42U2P_YB, PBA # LJ92-01739A, PCB # LJ41-08594A
• X-sus: 42U2P_XM(1 layer),
• Panel: Samsung S42AX-YD13

• The Y-sus makes a popping noise (note, not clicking) - a popping noise - when you plugin the unit. I see that the high voltage 330pF 1kV cap at location C5008 has destroyed itself.
• I replaced the high voltage cap with an equivalent part. This did not fix the TV.
• I disconnected all of the boards. The main power supply board correctly generates Vs (211V) and Va (54V). The power supply board goes into protection mode since the X/Y boards are not hooked up. I do see the Vs and Va rails ramp momentarily to their target voltages. So, that appears to be okay.
• If I ONLY add the Y-sus board, the TV tries to turn on twice (?), but then shuts down again.
• If I add the X-sus board to this, the TV tries to turn on twice (?), but then shuts down again. (same behavior as with Y-sus only)
• I tested the Y-buffer for shorts - no short that i can find through each of the ICs.
• I'm not hooking up the Y-buffer to the equation since the X-sus and Y-sus are suspect.
• I see that the X-sus has two IGBTs that are dead short (they are marked XG - Q4007, and XS - Q4001).

Is it even worth swapping out the IGBTs on the X-sus board?
Should the TV stay on if I have the Y-buffer and X-sus disconnected?

Thanks!
-Thomas

i just trashed a 32'' of that model bad panel,hope it's not your case good luck

[ngth82]

Re: Insignia NS-42P650A11 - click, click, off - shorted IGBT

Thanks.

If i can find out why the Y-sus causes the unit to click, then maybe it would be worthwhile attempting to replace the IGBTs on the X-sus.

As it stands right now, a $5 initial gamble to get the unit isn't worth the money that needs to be dumped in to get a complete set of sus + buffer boards.

[ngth82]

Re: Insignia NS-42P650A11 - click, click, off - shorted IGBT

Just following up with this thread.

I ended up taking the X and Y boards apart.

The Y-sus has a dead short between all of the IGBT pins at locations Q5003, Q5007 and Q5008. (MPN markings say "RJP30E2" - 360V, 35A, N-Channel IGBT). I removed the heatsink and unsoldered the parts. They tested bad as it still showed a dead short between the parts. The board pads show an open loop, thus confirming it was these three parts.

I did the same thing for the X-sus - i found a dead short on the two IGBTs labeled Q4007 and Q4001. (MPN markings say "RJH30E2" - 360V, 30A IGBT).

I purchased replacement parts this evening from eBay - qty 5 each (with a few to spare) - $9 in parts.

[ngth82]

Re: Insignia NS-42P650A11 - click, click, off - shorted IGBT

Hi all -
I received the replacement IGBTs today. I installed them and checked for shorts - none found.

I installed the y board, and connected the power from the main power board. Vs and Va ramp up then shutdown since the other boards are not installed. I then plugged in the x board as well. The power boards are up - vs and va are stable (210v and 54v per the panel sticker).

I turned it off and waited until the caps discharged then connected the y buffer board. I turned it back on and the power rails still appear to be good. I shut it off again, waited, then connected the ribbon cables from the PDP to the power boards. I made sure the LVDS cable was disconnected and forced the panel into the test mode by jumpering across Pins 3&4 on the T-CON.

but instead of getting a happy test pattern, I get what is shown in the attached image. What is the likelihood this is a buffer board problem? Or is it the panel?