Nec lcd195vx+bk

[ryan74]

I don't have a service manual and cant find any info on this monitor.
I want to determine if this is a power board issue, backlight, or panel.

This touchscreen monitor has standby.
After pressing power on, the led stays green about 5sec. then turns solid orange and stays on.
I dont see backlights or any display at all, not even a flash.
I took some volt readings from power board.(results on pic)
When I hold probed on the left side of board the voltage I read drops.
I tried unplugging the 4 connectors on left side and powering on and I get the same resopnse from led(green for 5sec. then orange) except after a minute or so the solid orange goes off.

[selldoor]

Re: Nec lcd195vx+bk

Pictures fall into the same category as capxon caps.

[ryan74]

Re: Nec lcd195vx+bk

Ok hopefully these are better. If you want to see something up close I can get better pics.
when I take pictures on whole boards im in that range where macro doesnt work any better.
Plus Im useing a cheap $40 camera but it is 12mp.

also, I would like recomendation for a cheap decent esr capacitance meter.

[mariushm]

Re: Nec lcd195vx+bk

Next time, don't even try to measure the voltage on those white connectors. You have 700-1400v and you may break your multimeter.

5 seconds is a bit long of a time, it's most likely just the monitor going into standby as it detects no signal.
Make sure you have some signal on the vga or dvi, turn the monitor on and see if it shows anything on screen.
If you don't, try again but point a flashlight at the screen at an angle and see if you see some picture.

In the last picture you have the display board. Check the voltages on the pins of two ICs, the ones with two pins soldered and a large tab soldered... one is on top left, above that yellow wire, one is below the two capacitors that are about in the middle of the board, between the two cables.

Check the voltages when the led is green AND when it's orange.

[selldoor]

Re: Nec lcd195vx+bk

Ok hopefully these are better.

not a lot - perhaps a samwha.

The top of the power board looks like its been quite hot- we are going to need a panasonic grade picture of the back of the board. read this
https://www.badcaps.net/forum/showthread.php?t=24612.

Also what numbers are on the top of the inverter transformers.Big Black rectangular with yellow stripe

[ryan74]

Re: Nec lcd195vx+bk

Ok, first off I did get ahead of myself a bit.
I hooked up to pc through vga, USB, and installed drivers on pc.
Now screen comes on for 1 second and looks perfect.
I can see VIDEO INPUT 1D-SUB on screen.
front led stays green after screen shutsdown.

the IC(AIC 1084-33PM) on upper left tested:
-green led
P1-0.0V.
P2-5.06V.
Lg tab-3.326V.

-Orange Led
P1-0.0V.
P2-5.09V.
Lg tab-3.325V.

Left Center IC(AZ11170-1.8EI I think):
-green led
P1-0.0V.
P2-3.565V.
Lg tab-1.804V.

-orange led
P1-0.0V.
P2-3.692V.
Lg tab-1.803V.

Sorry I forgot to rotate pics.
pic DSCF0005 goes with DSCF0009
DSCF0006 and 10
7 and 11
8 and 12

Inverter transformer #
80LL17T-24-DN G
Darfon 8292

I hope these pics pass Panasonic quality control.

[selldoor]

Re: Nec lcd195vx+bk

They may now be good but I cant read the number on the transformer - that is why I asked for it.

Anyway I have marked on the attached what I think should be the secondary windings
on one of the transformers - I would have marked both if they had been in the same pic.
POWER OFF Meter on ohms 2000 measure s1>s2 then find the same points on the other transformer and measure across those and post the results

[ryan74]

Re: Nec lcd195vx+bk

I had to edit post above and add transformer #
80LL17T-24-DN G
Darfon 8292

I have to use autorange on my DMM but both tested .498kohm with board pulled.

I could really use suggestions for a better meter and Im looking for a decent in circuit esr capacitance meter

[selldoor]

Re: Nec lcd195vx+bk

Good but bad - they look good so we have to look elsewhere.
At the top of the picture there are 4 components 3 between the two transformers and one a bit lower. Can you get the number off them, search for a data sheet and test them. Tests should be in retiredcaps guide which you need to read if you have not already :https://www.badcaps.net/forum/showthread.php?t=10419.
Your earlier "led " voltage regulators? tests look ok - v at middle pin is quoted in part number.
There are lots of posts about meters try and find one- or decide how much you want to spend and start a separate thread - retiredcaps is the meter guru and I am sure he will respond.
Early start tomorrow so I am off to bed.


Edit here is a meter link
https://www.badcaps.net/forum/showth...ighlight=meter

[ryan74]

Re: Nec lcd195vx+bk

the components you said to check are all the same part:
4512C
AA7YAJ

all the datasheets I find are something like AF4512C.
Im not sure if that will do.

If I cant find the right one can I just do resistance and check pin by pin?

Thank you for the help so far.

[retiredcaps]

Re: Nec lcd195vx+bk

I have to use autorange on my DMM but both tested .498kohm with board pulled.

I could really use suggestions for a better meter and Im looking for a decent in circuit esr capacitance meter

I'm not sure what you mean by "I have to use autorange on my DMM".

The Klein MM1000 is an autoranging meter by default. To measure resistance, you just set it to the ohms and it is done.

The Range button on the multimeter switches it from auto ranging mode to manual mode.

As suggestions for a better meter, what is wrong with the MM1000 and what do you want in a new one? What is your budget?

[ryan74]

Re: Nec lcd195vx+bk

I'm not sure what you mean by "I have to use autorange on my DMM".
The Range button on the multimeter switches it from auto ranging mode to manual mode.
As suggestions for a better meter, what is wrong with the MM1000 and what do you want in a new one? What is your budget?

Nothing is wrong with it except I get asked to set it to 200ohm range The decimal point moves when I cycle through manual but I don't know which is equal to 200ohm range. My budget is under $80.

Mainly right now I want to get a decent in/out of circuit esr/capacitance meter.

[ryan74]

Re: Nec lcd195vx+bk

I was considering upgrading dmm. I guess I'll wait and focus on esr tester for now.
For an esr I want something easy to use and preferably with in circuit testing.
It would be nice to test caps in circuit initially.
Twice now my dmm has tested good capacitance on caps that were bad. I can see how important esr is.

I looked through this and I like the esr-micro v4.0(it looks simple and easy) but I'm not sure. Its $85. Maybe something similar if you agree capacitance is not needed.
https://www.badcaps.net/forum/showth...ighlight=meter

[budm]

Re: Nec lcd195vx+bk

Please check these 4 MOSFETs.
The lamps or lamp's wiring can be the cause of the problem also, you will need test lamp to verify.

[retiredcaps]

Re: Nec lcd195vx+bk

Nothing is wrong with it except I get asked to set it to 200ohm range

Ignore the set your multimeter to xyz ohm/volt range instructions.

They are for people with manual range multimeters. Your multimeter autoranges.

In post #7, selldoor assumes you have a manual range meter and asks you to set it to the 2000 ohm range. Since your multimeter auto ranges, it will properly give you a reading of 498 ohms without you having to switch to manual mode. Trust me, most of my multimeters at home are auto ranging and I never use manual mode.

[retiredcaps]

Re: Nec lcd195vx+bk

For an esr I want something easy to use and preferably with in circuit testing.

In circuit testing is not 100% reliable. You must desolder and verify out of circuit.

[ryan74]

Re: Nec lcd195vx+bk

I know that's why I said I want to test in circuit initially.

[budm]

Re: Nec lcd195vx+bk

If your meter can only do auto range, then you have to make sure to tell us the letter display on the reading so we know if it is 1M (1 Mega Ohm), 1K, or just 1 on the display.
If you have two caps in parallel, one will high ESR will not show up when you try to check them in circuit.

[retiredcaps]

Re: Nec lcd195vx+bk

If your meter can only do auto range, then you have to make sure to tell us the letter display on the reading so we know if it is 1M (1 Mega Ohm), 1K, or just 1 on the display.

That goes back to this post

https://www.badcaps.net/forum/showpo...0&postcount=22

If you have two caps in parallel, one will high ESR will not show up when you try to check them in circuit.

[ryan74]

Re: Nec lcd195vx+bk

I tested mosfets and posted results on pic.