dell 2007 WFPb monitor ,no lights

[aortiz]

Re: dell 2007 WFPb monitor ,no lights

the lamps dont flash at all
i do have 19v at both sides of the fuse.
i dont know where INV-ON PIN IS IN THE INVERTER BOARD is.can you tell me please?
sorry for the delay,i am having a lot of trouble connecting,tomorrow i got to go buy another antenna.

[budm]

Re: dell 2007 WFPb monitor ,no lights

By the way, do you have 3.3V and 5V on that USB/SMPS board? I know you do not have the 12V.
I do not remember which test point is for the BL_ON, DIMM.
You need to take DC voltage readings on these three test points TP713, 714, and 716 when monitor is off and when it is turned on.

[aortiz]

Re: dell 2007 WFPb monitor ,no lights

i do have 3.3 v all the time,the 5 v show up when i turn on the monitor.
tp7-13 is 0 volts when the unit is off and when its on
tp7-14 is 2.75 when is off and 2.77v when is on
tp-16 is 0 volts when is off and 0 volts when is on.
i took this readings in refrence to ground whis is labeled tp712 on the power board.

[aortiz]

Re: dell 2007 WFPb monitor ,no lights

is 2.77v a normal reading ?is going to the + side of c142 ,10mfd,25v cap.i can not find where is going from there.
on the video logic card.

[aortiz]

Re: dell 2007 WFPb monitor ,no lights

bud,its almost midnite,i am going to bed.
tomorrow i will try to get connected early.
i lived in oakland calif for about 30 yrs and it just to be that sf bay its 2 hrs earlier than this part of mexico.anyway i will be here tomorrow morning around 9 our time to see if i had any replies.thank you bud,and have a good night.

[budm]

Re: dell 2007 WFPb monitor ,no lights

"i do have 3.3 v all the time,the 5 v show up when i turn on the monitor." That is good, because the common failure of this USB/SUB-POWER supply is due to failed diodes in the 5V or 3.3V buck regulator power supply.

"tp7-13 is 0 volts when the unit is off and when its on
tp7-14 is 2.75 when is off and 2.77v when is on
tp-16 is 0 volts when is off and 0 volts when is on."

Those voltages do not look right. I will need to find out what those 3 pins are.

"is 2.77v a normal reading ?is going to the + side of c142 ,10mfd,25v cap.i can not find where is going from there.
on the video logic card." I do not know what that C142 is.

[Davi.p]

Re: dell 2007 WFPb monitor ,no lights

Ortiz my test was another: with all connected up also pc connec. and swithced on does you see a dark image if you point a lamp from the side to screen?

[selldoor]

Re: dell 2007 WFPb monitor ,no lights

Here is another thread on a set which MAY have the same boards Aortiz perhaps you can
check they are the same. Unfortunately they dont manage to fix the set but has a lot of voltages at test points ( as there was no fix we still dont know if these are correct or not)
https://www.badcaps.net/forum/showth...ighlight=tp713
Post 2 is the "pointed lamp" test - in 3 years on this site I have never seen it referred to as that.

[Davi.p]

Re: dell 2007 WFPb monitor ,no lights

ok i have translated better, is "lamp bet" test, is more clear now?
English is strange "point the lamp" is correct "pointed lamp" is another thing..

[selldoor]

Re: dell 2007 WFPb monitor ,no lights

No that is a worse translation.
There is no name for this test you just have to say ......... try shining a flashlight (american for torch) at different angles onto the screen to see if you can see a dark/dim image of what the PC is producing

[Davi.p]

Re: dell 2007 WFPb monitor ,no lights

thankyou selldoor

[aortiz]

Re: dell 2007 WFPb monitor ,no lights

ok ,thank you bud.
could that 2.77v be the 3.3v being loaded down by something on the logic board?if i take out the cap,will i damage something else in the units when i turn it on to see if the voltage comes up? i tried disconecting connector cn702(the 7 pin connector that goes to the logic board) and the monitor wont turn on)
please advise

[aortiz]

Re: dell 2007 WFPb monitor ,no lights

yes ,i see a dark screen when i shine a lamp to it ,sideways,frontways,etc

[aortiz]

Re: dell 2007 WFPb monitor ,no lights

ok selldoor,thank you and i am going to definitly look at that thread.

[selldoor]

Re: dell 2007 WFPb monitor ,no lights

i tried disconecting connector cn702(the 7 pin connector that goes to the logic board) and the monitor wont turn on)
please advise

Simple explanation there are more scattered throughout the forum maybe some in the "stickies" at the front
There is an interaction between the boards. when you first plug in there should be at least a standby voltage though some sets also have the 24v to the
inverter.
When you press the on button a signal is sent to the power supply to turn the rest of the voltages on via pin pson or pwr or enable further signals are sent
to switch on the back lights via Blon pin and subject to other internal testing being ok it should all switch on.

[budm]

Re: dell 2007 WFPb monitor ,no lights

OK, I am confused:
"could that 2.77v be the 3.3v being loaded down by something on the logic board?"
"i do have 3.3 v all the time,the 5 v show up when i turn on the monitor."
So do you have 3.3V at the point as shown in the pictures and diagram I posted (#42) or you have 2.77V?
We are not getting any where here with so many unclear answers.

[aortiz]

Re: dell 2007 WFPb monitor ,no lights

sorry bud,
didnt mean to confused you.
that was just a dumb question coming from somebody who knows little about monitors but has the will to learn.
the reading is ,and still is 2.77v at the + side of c142 on what i call the logic board the one with the vga connector.
and the reading on the usb board tp35 (positive side of c44)still is 3.3 v.

[aortiz]

Re: dell 2007 WFPb monitor ,no lights

hello everybody ,after a long ,lonlely afternoon.,and thanks to all of you that pitched in ,budm,davip,selldoor and the treads that you guys recommended i read.
i really dont know what i did but,i definitly got a backlight,not very bright but its there,maybe the brightness control can bring it up.
i replaced c142,(blind shot) on logic board,and 3.3v came on at tp7-13,it was 0v.
i dont get a picture yet,but i got faith on you guys.
any sugestions as to where to start to look for data signal?
thank you all

[selldoor]

Re: dell 2007 WFPb monitor ,no lights

Wow! progress - do/did you have a pc connected producing a known image?
and is the lvds cable attached at both ends

[Davi.p]

Re: dell 2007 WFPb monitor ,no lights

what do you see on screen? Black with backlight, white ??