Westinghouse L2046NV

[frankNstein]

Hello everyone I am new here and this is my first post. I have a Westinghouse L2046NV monitor and the backlight is not working. It has a Delta DAC-19M005 DF Rev 02A power supply/inverter board. I have replaced Q205, Q206, C204,CE101, CE109, CE103, CE104 and F200. I have 5 and 15 volts at CN5. When the monitor is turned on the green light comes on for about five seconds and then starts to blink. I have spent a lot of time on this monitor and have found that there is no drive to the Mosfets. It looks to me like the drive comes from U200 and is buffered with two transistors and then to the gate of the Mosfets. I haven't looked to see if I have anything from U200 because it and the buffer transistors are on the bottom of the board. I was hopping that someone had this before or happened to have a schematic of this board. Thank you for your help.

[PlainBill]

Re: Westinghouse L2046NV

Hello everyone I am new here and this is my first post. I have a Westinghouse L2046NV monitor and the backlight is not working. It has a Delta DAC-19M005 DF Rev 02A power supply/inverter board. I have replaced Q205, Q206, C204,CE101, CE109, CE103, CE104 and F200. I have 5 and 15 volts at CN5. When the monitor is turned on the green light comes on for about five seconds and then starts to blink. I have spent a lot of time on this monitor and have found that there is no drive to the Mosfets. It looks to me like the drive comes from U200 and is buffered with two transistors and then to the gate of the Mosfets. I haven't looked to see if I have anything from U200 because it and the buffer transistors are on the bottom of the board. I was hopping that someone had this before or happened to have a schematic of this board. Thank you for your help.

Read this faq: https://www.badcaps.net/forum/showthread.php?t=1868

Now take pictures of both top and bottom of the board and attach them to your reply.

PlainBill

[frankNstein]

Re: Westinghouse L2046NV

Here are the pictures of the boadr and yes I know that F200 is not on the board, I took it off during testing.

[jetadm123]

Re: Westinghouse L2046NV

Hello "Frank"! After looking at your photo, it looks like your monitor uses the same power supply/inverter as the Westinghouse L1975NW. There's quite a long thread concerning this monitor at:

https://www.badcaps.net/forum/showth...hlight=l1975nw


Hopefully, you can get some good info from it. Please keep in mind that this thread covers the "AF" version versus your "DF" version and I'm not sure what the differences are.

[frankNstein]

Re: Westinghouse L2046NV

Thank you for the link and all your help. What I am having trouble with is something more than this link. I have no drive to the Mosfets. I did this type of work for about thirty years and have all the equipment but am having trouble because I don't have a schematic of this board and I can't read the part number on the driver IC. I hope someone can help me find the schematic and I will post what I find after the repair is completed.

[PlainBill]

Re: Westinghouse L2046NV

Thank you for the link and all your help. What I am having trouble with is something more than this link. I have no drive to the Mosfets. I did this type of work for about thirty years and have all the equipment but am having trouble because I don't have a schematic of this board and I can't read the part number on the driver IC. I hope someone can help me find the schematic and I will post what I find after the repair is completed.

Follow the link jetadm123 posted above. The identify the inverter controller and even provide a link to it's datasheet.

As far as the FETs not having a drive signal, check the backlight control signal from the logic card.

Finding schematics for these monitors can be very difficult. Quite often we have to depend on other's experience, then pay it forward. If I recall correctly, the identical power supply / inverter is used in an Acer AL1916W. That schematic might be available.

PlainBill

[PlainBill]

Re: Westinghouse L2046NV

Follow the link jetadm123 posted above. The identify the inverter controller and even provide a link to it's datasheet.

As far as the FETs not having a drive signal, check the backlight control signal from the logic card.

Finding schematics for these monitors can be very difficult. Quite often we have to depend on other's experience, then pay it forward. If I recall correctly, the identical power supply / inverter is used in an Acer AL1916W. That schematic might be available.

PlainBill

My bad. The Acer AL1916W seems to use a different board.

PlainBill

[frankNstein]

Re: Westinghouse L2046NV

PlainBill Thanks for the help. I will see what I can find with the Archer anyway, it might be close enough. If someone has a part number for U200 that would be a great help. I can't read the number on mine and that is where the drive comes from. I will do some more checking today.

[frankNstein]

Re: Westinghouse L2046NV

PlainBill- My board is using a BIT3713 IC for the inverter control (U200). I couldn't find much information on it but found the data sheet for a BIT3193. I read somewhere that they are the same and I was hoping that you might know if that is true. Are they the same? Is the pin-out the same too? Thanks for all your help

[anno]

Re: Westinghouse L2046NV

does the ic getting power on vcc pin ? so look for voltage on the vcc pin. check that.
then check with scope if u200 drives the mosfets (if you have a scope). if there is voltage but no output maybe the ic is defect

[frankNstein]

Re: Westinghouse L2046NV

I need to know if the BIT 3713 Nd the BIT 3193 are the same so I know what the pin-out is and then I can check all those things. Yes I do have a scope. Thanks for the help

[PlainBill]

Re: Westinghouse L2046NV

PlainBill- My board is using a BIT3713 IC for the inverter control (U200). I couldn't find much information on it but found the data sheet for a BIT3193. I read somewhere that they are the same and I was hoping that you might know if that is true. Are they the same? Is the pin-out the same too? Thanks for all your help

The information is covered in the other thread; I don't have personal experience. But as far as I know, they are identical; the part number was changed as part of the settlement of a copyright infringement case.

With the datasheet, an ohmmeter and the scope it should be very easy to verify the equivalence.

PlainBill

[frankNstein]

Re: Westinghouse L2046NV

I found four open transistors allinthe VDD supply, on-off and holddown circuit of U200. I am not sure I am reading all the number on them but this is what I can see.W2k and P13. Do any of you know anything about these numbers and what I should use as replacements? These are surface mount and their board numbers are Q22,Q202,Q209 and Q110. Thanks for all your help.

[PlainBill]

Re: Westinghouse L2046NV

I found four open transistors allinthe VDD supply, on-off and holddown circuit of U200. I am not sure I am reading all the number on them but this is what I can see.W2k and P13. Do any of you know anything about these numbers and what I should use as replacements? These are surface mount and their board numbers are Q22,Q202,Q209 and Q110. Thanks for all your help.

Those are marking codes, and are the bane of the electronics tech. In general, if you know the manufacturer of the component you can identify the true part number. There are cross references, but they are hopelessly out of date. I checked both codes and came up blank.

PlainBill

[frankNstein]

Re: Westinghouse L2046NV

PlainBill Thank you so much. I will keep checking.We're only working with about 8-10 volts and not much current so I think I can find something that will work. I'll keep you posted.

[HardHead]

Re: Westinghouse L2046NV

I found this tonight if anyone is interested.

http://www.avsforum.com/avs-vb/showthread.php?t=1113012

[dobber]

Re: Westinghouse L2046NV

I have a 19in widesreen Westinghouse, that had a problem like that. On mine, I found that I had a burnt out mini fuse on it going to one side of the back lighting causing it not to start. I just bypassed it do to the fact that there was a second one in line just down the chain a bit. It has worked for about 2 years so far. Sorry that I have no pics, it was long ago that I fixed it, but maybe it will help.