Insignia ns-42pdp (lg pdp42x30000)

[tom66]

Re: Insignia ns-42pdp (lg pdp42x30000)

Unfortunately the pictures really aren't clear enough to be useable. Those pictures are my eyes - I do not have this chassis in front of me (I last worked on one nearly 2 years ago!) - so they really need to be good and clear, which might mean using a different camera.

However I do have a guide which indicates some possible tests you can do, in the meantime:


Page 60, 62 and 66 are relevant for now. Please test and adjust as indicated.

[DaveL]

Re: Insignia ns-42pdp (lg pdp42x30000)

If I didn't need a camera everybody I know would have one...I'm fixing to buy a better camera.

[tom66]

Re: Insignia ns-42pdp (lg pdp42x30000)

Sods law, eh?

For now, you can use the pictures in the guide.

[DaveL]

Re: Insignia ns-42pdp (lg pdp42x30000)

Ok...From pages 60,62 and 66...

I'm just posting the ones that were not right and would not
calibrate out from their pots...

VY-23-20 as low as it would go. Started at 23 and ends at 20.

Z BIAS-156-152 as low as it would go. Start 156 ends 152.

All other adjustments are correct now.

[tom66]

Re: Insignia ns-42pdp (lg pdp42x30000)

So Vy and Vzbias would not adjust? Vscan was OK?

[DaveL]

Re: Insignia ns-42pdp (lg pdp42x30000)

Va and Vs were 1-2 volts off and both adjusted correctly.

Z bias was at 156 and would only adjust down to 152
-VY would just bounce from 23 to 20 no matter which direction I turned the pot.

[tom66]

Re: Insignia ns-42pdp (lg pdp42x30000)

Ok, so what is the sticker rating for Vzbias?

Can you try unscrewing the Y-buffer boards (these boards attach to the Y-sustain and have the orange ribbons coming out of them - do not remove the orange ribbons as they are a pain in the arse to replace.) Unscrewing them will electrically disconnect them from the circuit, so then if -Vy returns to normal, it would indicate bad buffer boards are causing a fault.

And I'm guessing Vscan / Vsc measured correctly.

[DaveL]

Re: Insignia ns-42pdp (lg pdp42x30000)

Sticker rating for Z bias is 100

OK..The Y buffer is the long board to my left with all the ribbon connectors?
This board is held in place by 3 screws...Do I disconnect Y buffer from the 2 connectors on the Y board?

[ERICSSON89]

Re: Insignia ns-42pdp (lg pdp42x30000)

yes disconnect the ybuffer from the y board

[DaveL]

Re: Insignia ns-42pdp (lg pdp42x30000)

Ok...With Y buffer now disconnected from Y board the reading on Z bias is now as high as 143 and as low as it will go is 128. The readings before were 156 to 152. Sticker is 100

[DaveL]

Re: Insignia ns-42pdp (lg pdp42x30000)

From looking at individual boards on a site,the board I disconnected is the Y driver...the Y buffer is mounted on the left bottom of the panel and marked XL.

[tom66]

Re: Insignia ns-42pdp (lg pdp42x30000)

That board is the X-buffer. You want to disconnect the boards running from the top to the bottom of the panel, on the left hand side when looking from the back of the TV.

Make sure to fully secure the metal heatplate on the X-buffer, if you've removed it already.

[ERICSSON89]

Re: Insignia ns-42pdp (lg pdp42x30000)

now he is making mistakes I think he should upload picture of the inner full back side of the set with cover off

[DaveL]

Re: Insignia ns-42pdp (lg pdp42x30000)

No..I didn't bother the X buffer.
I disconnected the board on the left with the ribbons labeled YDRV/TP that plugs into the YSUS board.

[DaveL]

Re: Insignia ns-42pdp (lg pdp42x30000)

Lets not do anything that involve my camera! LOL!!

[tom66]

Re: Insignia ns-42pdp (lg pdp42x30000)

Ok, and please check -Vy with that board removed too.

[DaveL]

Re: Insignia ns-42pdp (lg pdp42x30000)

Vy now bounces between 24 and 22

[DaveL]

Re: Insignia ns-42pdp (lg pdp42x30000)

VSC is at 120

[tom66]

Re: Insignia ns-42pdp (lg pdp42x30000)

Ok, it sounds like you have a problem with the Y-sustain board. Probably the IPM on it. Info about testing the Y-sustain IPM is here:

http://blog.coppelltvrepair.com/2011...s-ipm-for.html
(You can do the test in circuit)

The IPM is the large device mounted under the heatsink. It is very difficult to remove although with patience and skill it can come off. I haven't ever tried to replace one.

This fault could also potentially be caused by a PASS FET failure, these would be three MOSFETs mounted on the heatsink on the Y-sustain board.

[DaveL]

Re: Insignia ns-42pdp (lg pdp42x30000)

Ohhh ok..
I have to run to the pharmacy right now...when I return I will look at the IPM info.
Thank you for your help.I really appreciate it.
Be back in about an hour.