Nec lcd195vx+bk

[budm]

Re: Nec lcd195vx+bk

OK, no shorted out MOSFET's. I can only suggest you to find out if the lamps or lamp's wiring are bad or not. Or have the test lamps to find out if the inverter board is OK or not.
Or make two test lamps using old CFL:
http://s807.photobucket.com/albums/y...g%20old%20CFL/

[ryan74]

Re: Nec lcd195vx+bk

I will make 2. It looks like any will work. I have old lamps from 32in tv or I can find a few screw in twisted type.
Thanks all

[budm]

Re: Nec lcd195vx+bk

Lamps from 32" may be too big for the inverter to drive but you can try. 14W or less twisted type CFl works.

[ryan74]

Re: Nec lcd195vx+bk

Im taking apart the twisted type but was wondering where to connect it for testing.
blue, black,pink, white

[selldoor]

Re: Nec lcd195vx+bk

budm shows one connection in this pic
http://s807.beta.photobucket.com/use...tml?sort=3&o=8

have you got a spare plug.

Should be 14w or less

[ryan74]

Re: Nec lcd195vx+bk

I found a 13 and a 14w.
I cant seem to find a plug to fit.
it looks like the pink and white stay plugged into board and blue and black go to test lamp.

[selldoor]

Re: Nec lcd195vx+bk

The idea (only really works if you have spare plugs) is that you put a plug on a lamp and substitute it one at a time for one of the panel lamps. If you have two it cuts down the testing time and means if two panel lamps have gone you may still get two to light.
If you dont have a plug you can either solder the test leads to the back of the board where the socket pins are soldered or you play russian roulette and cut one of the leads to get a plug.
A pre test test to try and find a bad bulb/wireing would be to plug in one bulb at a time and see if it flashes. Not always conclusive but if 3 flash and one doesnt then that is most likely to be bad.

EDIT EDIT

CARE IS NEEDED POWER SHOULD BE OFF WHEN PLUGGING could be
1200volts.

[ryan74]

Re: Nec lcd195vx+bk

I pulled the female pins out from 2 connectors i had.
The blue and black connections stayed lit with 2 lamps attatched.
I will move on to test pink and whits connections.

[selldoor]

Re: Nec lcd195vx+bk

Cant remember whether you are testing inverter transformers or panel bulbs but as well as getting the curly cfls lit you should be observing what the panel is doing and reporting

[ryan74]

Re: Nec lcd195vx+bk

in the pics above I had 2 lamps connected. each on black and blue wires.
both test lamps lit and stayed on. backlight also seemed to stay on.

I switched test lamps to the white and pink testing the same as above.
test lamps shutdown after 1-2 sec.

I disconnected bottom test lamp and reconnected connector and retested.
test Lamp stayed on.

Having just one test lamp on CN204(pink and white wires on bottom left)
test lamp shutdown.

with a test lamps on both sets of pink and white wires the bottom transformer made a noisesounds like bacon frying lol..
I do not hear it with 1 test lamp connected and im sure i had it connected right.

[selldoor]

Re: Nec lcd195vx+bk

Lost me there - its easy to do and its getting late over here.
Use just one test lamp and remove one panel lead, plug in the test lamp and see if it stays lit. If not it is likely one of the other three is bad so plug the first one back in and remove the second and plug the test in. If they dont stay lit then it must be one of the last two. So plug the second one back in and remove the third and plug in the test and test.
If having done that they never stay lit then two bulbs (or the wiring) must be dead.

Keep remembering you are dealing with HIGH voltage.

[ryan74]

Re: Nec lcd195vx+bk

from top left going down. Single lamp test.
CN210(bl/bk wires)
test lamp- on 1 sec
backlight- on 1sec

CN202(p/w wires)
test lamp-stayed on
backlight- stayed on

CN204 (p/w wires)
test lamp- 1 sec
backlight- 1sec

CN205 (bl/bk wires)
test lamp- 1 sec
backlight- 1 sec

-with a pair of test lamps on both connectors that have blue and white wires, test lamp and backlight stayed lit.
-with a pair of lamps on both pink and white connectors test lamp and backlight shutdown.

Edit-am i correct in suspecting the lamp for CN202?
If so can it usually be replaced or reaipaired?

[ryan74]

Re: Nec lcd195vx+bk

I decided to open the panel and see if i could get the lamps out and noticed a bad panel screen. couldnt see it assembled. this must be the problem or a big part of it.

[budm]

Re: Nec lcd195vx+bk

The test you have done with the test lamps, and the lamps stay on, it proved that the inverter circuits are fine. It just saves so much time troubleshooting.

[selldoor]

Re: Nec lcd195vx+bk

Edit-am i correct in suspecting the lamp for CN202?
If so can it usually be replaced or reaipaired?

Yes you are correct and yes it could be replaced.

I would set it up with the test bulb and a source so you can see clearly what the panel damage is. For a 19" monitor it may not be worth trying to get new parts.What some people do is find out EXACTLY what panel is in there then research what monitors have that EXACT panel then put it on one side and hope a one comes up somewhere with a good panel but faulty.
If nothing else you could use it to test other panels or part it out.