Dell 1504FP Monitor Year of Manufacture 2002

[matthmal]

Re: Dell 1504FP Monitor Year of Manufacture 2002

will do and let you know.

May I ask you what that glue is?

[selldoor]

Re: Dell 1504FP Monitor Year of Manufacture 2002

https://www.badcaps.net/forum/showthread.php?t=13813

The glue seems to be used for a number of reasons
Hold components during wave soldering.
Shield high voltage connections
Cut down on vibration
Support top heavy components
Cause items to break down quicker than they would (What who said that)

[matthmal]

Re: Dell 1504FP Monitor Year of Manufacture 2002

Ok, here are the readings after cleaning the FET.

POWER OFF, 2000ohms:

Pin 1 to Pin 2 -> 695
Pin 1 to Pin 3 -> 1
Pin 2 to Pin 3 -> 1

[selldoor]

Re: Dell 1504FP Monitor Year of Manufacture 2002

I take it that "1" is on the left hand side meaning off scale rather than 1 ohms.
In which case the mosfet is ok - you can put it back in and retest voltages
at the connector. use 20vdc - then try again with the main board to panel cable (LVDS)unplugged.

[matthmal]

Re: Dell 1504FP Monitor Year of Manufacture 2002

yes that is what it means. i will retest the connectors and let you know.

[matthmal]

Re: Dell 1504FP Monitor Year of Manufacture 2002

POWER ON, VDC20:

Pin 1 -> 0.50
Pin 2 -> 0.57
Pin 3 -> 0.65
Pin 4 -> 0.31
Pin 5 -> 0.92
Pin 6 -> 0.31
Pin 7 -> 0.63

[selldoor]

Re: Dell 1504FP Monitor Year of Manufacture 2002

And with cn401 unplugged? Is there any marking on the board to suggest what the pins should be.

[matthmal]

Re: Dell 1504FP Monitor Year of Manufacture 2002

Everything is in its exact place. Do you suggest to remove the mosfet and re-try?

[selldoor]

Re: Dell 1504FP Monitor Year of Manufacture 2002

No - just take the lvds lead from the main board to the panel out I think its cn401. then switch it on maybe the backlights will come on but no picture, then take the 7 voltages again. - Did you try the hairdryer?

[matthmal]

Re: Dell 1504FP Monitor Year of Manufacture 2002

I haven't tried the hair dryer yet, let me try it.

Do you mean C101 or C401?

I noticed something now when removing the leads and leaving the power board by its own. I tested all the voltages and they came all with 0.0 and something but after a few minutes the voltages started to change. They go up very slowly to these and if I left them for another 5 mins they could have gone more up.

POWER ON, VDC20:

Pin 1 -> 4.01
Pin 2 -> 0.05
Pin 3 -> 0.7
Pin 4 -> 1.6
Pin 5 -> 5.7
Pin 6 -> 3.4
Pin 7 -> 4.4

Please note that I can't light up the bulbs without the vga board connected as this board by has the invertor board connected to it. i.e. the board that lights up the bulbs

[selldoor]

Re: Dell 1504FP Monitor Year of Manufacture 2002

Ok - you are not listening/reading/doing?
In your first picture right at the bottom of the main board there is a connector socket
CN401 - I wanted you to try it with the power supply the main board and the inverter board connected but the cable at CN 401 disconnected.

As you apply voltage to the boards the caps heat up. As the cap get warm the ESR
drops and they start to work a bit better. I have suggested twice I think that you heat the caps with a hairdryer but you have not said you have done that?

[matthmal]

Re: Dell 1504FP Monitor Year of Manufacture 2002

I am reading but apparently I did not understand. I got you now.

My apologies......

I will try exactly what you told me and I will post all the results. Sorry again.

[selldoor]

Re: Dell 1504FP Monitor Year of Manufacture 2002

Ok - no rush - Im off to bed - early start tomorrow.

[matthmal]

Re: Dell 1504FP Monitor Year of Manufacture 2002

I have done the hair dryer thing and before I started the test a big spark occurred.

POWER ON VDC20:
Pin 1 -> 6.89
Pin 2 -> 5.5
Pin 3 -> 4.02
Pin 4 -> 3.7
Pin 5 -> 2.5
Pin 6 -> 2.04
Pin 7 -> 1.8

Please note that the voltages started to go down.

[selldoor]

Re: Dell 1504FP Monitor Year of Manufacture 2002

Big Spark?? where from? could be a bad solder joint - can you do a good picture of the area. I think just get some new caps in.

[matthmal]

Re: Dell 1504FP Monitor Year of Manufacture 2002

yes it was a big spark and it did hit me hehe. I marked an estimation from where the spark came.

[selldoor]

Re: Dell 1504FP Monitor Year of Manufacture 2002

Is that pic after the spark - I see the board is balanced on top of the metal frame I hope you dont run tests with it like that.

Did the board work (as well as it ever did) after the spark?
The mains lead plugs in in that area - maybe the plug was just loose?

[matthmal]

Re: Dell 1504FP Monitor Year of Manufacture 2002

i have now replaced all those caps and the voltages are even worse, they are ranging from 0.03 to 0.01 :S

[selldoor]

Re: Dell 1504FP Monitor Year of Manufacture 2002

Great !!

Start again - perhaps something got overheated with the hairdrier and burnt out.
First check that you got all the caps in the right place and the right way around.
Pale stripe (negative )on the black semicircle side. You can see which caps went where for most of them at least from the pics in the thread.

Working just on the power supply power off test the two black barrel fuses.
If they are ok then plug the board in and switch on. Meter on vDC600 test the BIG cap
CAREFULLY - High voltage. Test for a few seconds to see if it remains stable.

[matthmal]

Re: Dell 1504FP Monitor Year of Manufacture 2002

will do and let you know