LG 50PC3D Issue

[tom66]

Re: LG 50PC3D Issue

Do you have a Harbor freight near you? They have a usable DMM for about $4 most days... nothing special but will get the job done...

[notatvrepairguy]

Re: LG 50PC3D Issue

Doesn't sound familiar so I don't think so.

I'm ok with the $20 Radioshack version if it will do the job. I might just return it after I'm done, hahahhaha.

Do you need more info or anything to help me figure out what to test?

[tom66]

Re: LG 50PC3D Issue

Looks OK but note battery not included.

[notatvrepairguy]

Re: LG 50PC3D Issue

Noted! I'll bring some batteries home with me.

Would you mind writing up a quick and dirty plan for what I'm testing and how to do it?
Or do you have any references I can use?

I'm not completely dumb when it comes to this stuff, just don't want to cause any damage or anything. I'm sure I can figure it out if you can get me pointed in the right direction.

Thanks!

[tom66]

Re: LG 50PC3D Issue

Page 180 ~ 181


Use DC 500V range, red probe in Volt/Ohm, black in COM of multimeter.

[notatvrepairguy]

Re: LG 50PC3D Issue

Ok thanks, that definitely helps me understand where I'll be testing.

In regards to the actual testing, would you mind confirming what I'm thinking?

You asked me to test the VScan, I assume this is the VSC ?

I understand how to setup the meter, but where do I put each probe on the actual board?
It looks like there are 2 VSC TP (test points?) in that photo.

Do I put red probe on one TP and black to a ground on the frame or housing of the TV?

Sorry for being so needy, just want to make sure I'm doing it right the first time!

I'll be home in about 2 hours and will be able to get some results.

[tom66]

Re: LG 50PC3D Issue

You put the red or black on different ones, order doesn't matter for now, if you get a negative result just ignore that.

VSC = Vscan on LGs.

[notatvrepairguy]

Re: LG 50PC3D Issue

Excellent, thank you again.

I'll report back with readings in a couple of hours.

Anything else I should check while I'm doing the VScan?

[notatvrepairguy]

Re: LG 50PC3D Issue

Also, I found out we do have a Harbor Freights close to me!

They have this for $5, WITH batteries!

http://www.harborfreight.com/7-funct...ter-69096.html

[tom66]

Re: LG 50PC3D Issue

Yep that's what I'm talking about - it's an OK meter considering it's only $5.

[notatvrepairguy]

Re: LG 50PC3D Issue

Ok! I'm pretty sure I did it right, and nobody/nothing got hurt!

I am getting readings at 113-115. You mentioned 150 should be a normal value, sounds like we're barking up the right tree!

What is your next recommendation? Thanks for all the help!

[tom66]

Re: LG 50PC3D Issue

150V is for a newer panel; can you check what your panel is rated?

It is written on the label: N.A. / -Vy / Vsc / N.A. / Vzbias

[notatvrepairguy]

Re: LG 50PC3D Issue

I can't find a label that matches those exactly, but I did find this :

MODEL : PDP50X3####
Rating
Total Max Watt : 500W
Max Volt(---___) : 5.25V/61Va/200Vs
Max Amps : 4.0A/2.2A/2.0A

[notatvrepairguy]

Re: LG 50PC3D Issue

Oddly enough there is a second label that's similar, and appears to be older by the looks of it.

MODEL : PDP50X3####
All Voltage : DC (---___) 5V
Va : 60V VS : 192V
120 / -200 / 120 / N.A / 93
Max Watt : 400W (Full White)

[tom66]

Re: LG 50PC3D Issue

Your Vscan is OK then.
Can you check -Vy too?

[notatvrepairguy]

Re: LG 50PC3D Issue

(-)185-(-)187 on the -Vy

[notatvrepairguy]

Re: LG 50PC3D Issue

Not sure what else I can test, let me know if you have any other ideas.

[tom66]

Re: LG 50PC3D Issue

Can you see the points marked Vset_up or Vset_dn (adjustment points)
Note original points down (a marker across the screw will help locate it) and then try adjusting Vset_dn then Vset_up - see if the picture changes.
There is no "correct" setting - you can't test them with a DMM unfortunately.

[notatvrepairguy]

Re: LG 50PC3D Issue

I see them, and marked them.

How much adjustment should I be trying?

Baby steps? Quarter turn? Half turn?

What should I expect from up or down?

[notatvrepairguy]

Re: LG 50PC3D Issue

Also, should I be making these adjustments while the set is powered on, or off?