[spatz]

Hi NEC experts,


I sold a XG135 to a customer and he has a failure message telling FD which indicates that something wiht the HV unit is wrong. Is there anybody who did have this problem and what was the fix. I want to avoid senseless shipping if it is one of the "regular" problems and already known to some of the XG experts here.

Thanks for your the help.

 

[Doug Baisey]

spatz,

If this worked when you sent it and doesnt now have him look for a broken CRT neck from shipping or also check for a crack across the face of the tube. FD is usually that or the HV power board. Doug

 

[Paul Bruckner]

I just went through two HV_PWB's on my XG unit. First one just went on its own. The second (my fault) was from a nice blue arc from the high voltage probe of my scope to the chassis. Both times "FD" errors were displayed.


I did have an odd FD error some months ago that was input related to my HTPC when changing screen resolutions. Rebooting clear that up.... still not sure why that happened.


Regards,

Paul

 

[johnwcookjr]

Spatz,


I too had to replace/repair an HV card due to this error. There aren't that many active components on this particular card. If you (or if you know someone who is) a competent tech finding the expired semiconductor shouldn't be hard.


In my particular case, one of the final HV driver transistors was shorted base to emmiter causing the supply to shut down prematurely.


Should the HV card turn out to be what's causing you problem, you should check the HV levels via high voltage probe at the CRT's cathode for proper voltage. I'm currently out of town on a business trip and don't have the manual in front of me. You'll definately need to know which potentiometer on the HV card to adjust and the proper voltage level to set should you have to repair or replace this card.


Doug can probably acquire the levels and potentiometer for you or email me if you need help and I'll send the data out to you on my return home next week.



John

 

[Curt Palme]

See if the customer can unplug the red HV leads to each tube one at a time. Doug is right, I have had about 4 tubes snap in shipping despite careful packing. The weight of the yokes seem to do it.


If he can disconnect the HV leads, you'll see if it's a snapped neck or not.


Curt

 

[Doug Baisey]

Spatz,

If it is the HV board and not a cracked tube, the HV plus the protect 1-2 pots will need to be set up. Doug

 

[Paul Bruckner]

Adjustments for HV_PWB


HV ADJ. - VR5501 32Kv +/-.1 all white NTSC signal

(CAUTION: only for the experienced)


HV Protect (1) - VR5502 - .15 =/-.1v in high beam mode (ABL SW S5502 depressed) max contrast and brightness.

HV Protect (2) - VR5503 - same as above.


(note: minimum voltage is counter clockwise)


Return S5502 to normal position.

Return contrast and brightness to normal.



Regards,

Paul

 

[spatz]

Thanks that was a lot of very helpful information, and as the projector was not shipped but in a fixed installation for over a year I would assume that the final driver transistor went out. I will ask my customer to take out that board and sent it over to me.

Thanks folks, I will report my results for creating a better database.


Uwe