DELL 2405fpw

[Mirage00]

Re: DELL 2405fpw

Ok It seem like most of the green 220u CAPS are tied to the B+ CAP circuit I''m testing. Is that possible?

[Mirage00]

Re: DELL 2405fpw

Is there anyway I could get the schematic for this board? It says a BENQ L1E01 A02

[budm]

Re: DELL 2405fpw

Well, I do not know what other method you can use to find out where the B+ feeding that point comes.

[Mirage00]

Re: DELL 2405fpw

Make sure to use the lowest Ohm (200 Ohm scale) setting on your meter, no power to unit.

Yes to both

[budm]

Re: DELL 2405fpw

Make sure to use the lowest Ohm (200 Ohm scale) setting on your meter, no power to unit.

[Mirage00]

Re: DELL 2405fpw

OK, now we have established B+ pin (positive leg of the cap) to be the connection point that supply the B+ to the T-CON, now we just need to find out where it is connected to the other component on the main board. It is not easy but not much we can do since we do not have the diagram for this monitor.

Ok, I started testing the B+ on the CAP to the outlined components and many of them test 0 when connected. I thought there would only be only one?

[selldoor]

Re: DELL 2405fpw

@retiredcaps - thanks - will watch it tomorrow when the two cells are fresher.
I didnt mean distracted on the initial recognition - you said later that you
would have to look up the datasheets. Anyway having got them are his measurements of them within spec?

[retiredcaps]

Re: DELL 2405fpw

Two of the "voltage regulators" are mosfets - think retiredcaps got distracted setting fire to his dinner.

Since I couldn't read the part numbers, I took a guess based on its packaging.

I attach the datasheets as despite everyones efforts I still dont know what they mean.

My fellow Canadian, Afrotechmods, makes excellent easy to understand and short videos.

http://www.youtube.com/watch?v=Te5YYVZiOKs

[budm]

Re: DELL 2405fpw

The F, FR: they are MOSFET's

[selldoor]

Re: DELL 2405fpw

Two of the "voltage regulators" are mosfets - think retiredcaps got distracted setting fire to his dinner.
I attach the datasheets as despite everyones efforts I still dont know what they mean.

[budm]

Re: DELL 2405fpw

NO , we are looking for direct connection with less than one Ohm resistance, just think of it like looking for another end of the wire, but in this case, it is the copper traces on the board.

[Mirage00]

Re: DELL 2405fpw

Ok so when I connect to each of the devices in the outlined section does it matter what leg? + or -

[budm]

Re: DELL 2405fpw

OK, now we have established B+ pin (positive leg of the cap) to be the connection point that supply the B+ to the T-CON, now we just need to find out where it is connected to the other component on the main board. It is not easy but not much we can do since we do not have the diagram for this monitor.

[Mirage00]

Re: DELL 2405fpw

I expect the pins on the right of the connector will be for B+ as selldoor said, and the + leg of the cap also check out to be 0 ohm as well to the fuse?

Thats correct and the all check out at 0 ohm including + end of CAP.

[budm]

Re: DELL 2405fpw

I expect the pins on the right of the connector will be for B+ as selldoor said, and the + leg of the cap also check out to be 0 ohm as well to the fuse?

[selldoor]

Re: DELL 2405fpw

I think its just the last 4 pins at that end of the connector that are usually the power.

[Mirage00]

Re: DELL 2405fpw

OK please bare with me, I'm not sure how to check this. I hooked up the DMM in OHM mode with the monitor off to each one of the pins and the other end on the FUSE and most of them read 0.

[Mirage00]

Re: DELL 2405fpw

Thanks budm, I will check later today.

[budm]

Re: DELL 2405fpw

0.34V at the T-CON fuse, means the T-CON is not getting the voltage for it to run.
Please verify of what I think the connections are.
We need to find that switched transistor that supplies the B+ to the T-CON fuse.

[Mirage00]

Re: DELL 2405fpw

Nothing shows on the LCD. The screen is a greyish black, the backlight is on because I can see the ccfl lit. Here is a pic of the monitor, its hard to see ( I was holding it up) but it shows the lights and buttons working at the bottom and the screen backlight on.

BTW is this considered a white screen? Only the backlight is on.