[genmax]

Out of the blue. blue went down.. On an XG135LC (1351) Weird behavior too. No Error code (00), 00 is the norm isn't it? No noise, no sounds, nothing hot, just no blue... almost.


I power cycled, and left unplug for about 5 minutes, tried to get the high voltage lines switched at the block but couldn't pry the line off without force so I stopped. I then applied power again to try to get a handle on the symptoms. Here what I see now.


First, there is normal filament light when compared to the others, checked everything that could come loose for looseness and nothing is loose, checked everything for temp and everything is seems to be a normal warm.


Second, When I switch to a null input, and put up the all white TP and toggle the guns, blue does not come on at all under any circumstances. When I switch to the HTPC on the A input board, same as results as with the test pattern. But when I switch to the HDTV on the B input board, blue lights up with no focus, or so I think; based from looking at the screen. I never got to look at the tube. But blue is a haze and low intensity.


Third, when I cut off red or green, blue cuts off too. Turn red on or off blue goes with it. Same with green.


At this point I powered down and unplugged, figuring it was best to say HELP


Thanks in advance,


Marc

 

[techman707]

Have you tried swapping neck boards as a starting point?

 

[genmax]

Not yet, I was wondering if the problem was up stream because of the way blue came on selectively. But who knows, I'll give it a try, can't hurt. It's wierd though, the way it's seems to be related to the input card and/or signal.


Thanks,


Marc

 

[Clarence]

OT: Reminded me of an old college saying...

"She's pretty from the..."
Quote:

Nec Down... Nec Down...

 

[genmax]

LOL... even though I'm crying! Actually, I was thinking of a line from "Undercover Brotha", "Pimp Down! ... PimpDown!"...


Don't ask me why that was in my head, haven't a clue.


Marc

 

[techman707]

Quote:

Originally posted by genmax LOL... even though I'm crying! Actually, I was thinking of a line from "Undercover Brotha", "Pimp Down! ... PimpDown!"... Don't ask me why that was in my head, haven't a clue. Marc

I know why you were thinking that. CRT projectors are like whores, they take all your money but sometimes don't want to come...on.

 

[madclammer]

LOL... even though I'm crying! Actually, I was thinking of a line from "Undercover Brotha", "Pimp Down! ... PimpDown!"...


LOL....Theres alot of that film that will be stuck in my head for a while too. Best of luck with your Pimp.

 

[Chuchuf]

The very first thing I would do is to swap the B and G input connectors. Based on your TP's I don't believe that to be the problem but try it anyway and see if the problem "follows" the input.

Swapping the neck boards is impossible on the XG without sliding the CRT's forward. There just isn't enough room in that compact chassis to do that. And taking the tubes loose on the ceiling is not for the inexperienced, so if you have to go that route take the unit down.

So here is what I would suggest first. There is a signal lead that goes into the neck board. You have to remove the shields to get to it. Try swapping the signal leads from you B & G and see if you get a normal picture on the G. If so then the neck board of the B "could" be the problem.

I have seen neck boards go bad on the XG's before. Not many though.


Terry

 

[genmax]

Will do Terry. I did try every combination with the source lines comming into the input boards with no difference. I do believe the problem is down-stream from there. I'll try the signal lead switch as you suggested and report back. The XG is on the floor BTW.


Thanks again,


Marc

 

[genmax]

Ok, swapped the signal inputs on the neck boards between G/B and no difference. With the leads switched, using the svideo on the C board, there was no emissions from the blue tube, and the green tube functioned normally using the blue controls.


I really appreciate the good divide & conquer advice. I was in need of a way to break this down.


So, I made some more observations:


Svid signal on C board = no blue


1080i on B board = blue but not normal. I was only observing the All white pattern but I could see blue light up but not full brightness and the intensity of blue varied when I cut R/G on and off. So there is at least some high voltage. Is it possible to switch the HV line at the block?


Since it appears as though the problem is after the signal input to the neck board, what is the next step to weed something out. Should I try to isolate out the HV or neck board next. Or something else?


Thanks for helping!!


Marc

 

[Chuchuf]

Marc,


I think that the next step will be to swap the neck board. The G Neck board has a fan on it that the R & B don't so you may want to swap the R & B.

You are getting into an aear that involves high voltages so I won't tell you how to do this but I will say that you will need to get the tubes further forward in order to get th neck board off. Make sure you are careful with the R & R of the neckboards and that you put every lead back on the neck boards before you fire it up.


Terry

 

[genmax]

Hey Terry, good timing. I was just about to post the same..


I got the blue neck board out, I slid the card cage up and that made plenty of room. I then noticed what you said about the green neck board and was posting about using the red.


Anyway.. I'll know more in a few...


Thanks for helping!!


Marc

 

[genmax]

Ok, just using null input and swapping B/R neck boards, the blue comes up with what looks like normal raster. However, red filament does'nt even come on.


So, I'm gonna take the blue neckboard under a jeweler's loop and look for bad joints...


Thanks for the directions guys, seems to be narrowing down.


Marc

 

[genmax]

... I hope.


The red filament was cold because I bent a pin. Fortunately this was fixed and ok. The problem does travel with the neck board, so how does one get one of these repaired or replaced. Does anyone here have a spare to sell, or perhaps even to test with?


Anyway, I'm kinda stuck at this point because I'm not sure what to do with the part. Should I seek an RMA with NEC?


Totaly clueless at this point.


Marc

 

[genmax]

Anyone have suggestions on how to get an NEC neck board replaced/repaired??


TIA,


Marc

 

[Chuchuf]

Marc,


I have one that I can sell you. EMail me at [email protected] Include the P/N of yours.

It's easy to bend the pinc as you found out so be careful cause they can break pretty easy.


Terry

 

[Tinman]

Eeeek! Another Marc on the forum! ONE is bad enough! LOL


I'd bet the IC on the neck board died. I'd take Terry up on that replacement board.


Marc

 

[Mark Fry]

I also have a full spare of neck boards as well


Mark

 

[genmax]

They're comming out of the wood work!!! Marc(k)s that is....


How much does one cost anyway. I would love to get my hands on one pretty quick as you can imagine.


Marc

 

[Mark Fry]

I dont think it is kosher to discuss price ...on the forum but email the prospective sources Terry ,myself , probably Eric as well .and they can give you info direct...always include part number...


Mark....