Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

[kasatmata]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

thanks

[dnyaj]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Can anyone help me? I pickup a dell 2007FPb and the problem is that the LCD wont stay on. It keep on shutting off and turn itself back on without me hitting the power button. Sometime it stay on for a few minutes. I had re-solder the connection for the power and all the caps but still won't stay on. Let me know if anyone have a solution or what to test.

[Badgen]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Hello everyone.
I need to know breackdown voltage of ZD701.
Can anyone help me, thanks

[a69]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Hi all.
Need a circuit on the monitor DELL 2007

[chad720]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Hi there, I had the exact same simptoms as tboxxx, so I don´t think if I should open a new post. No response of the panel buttons, vga keeps blinking and only 19V on the conectors.

1) I had found on the USB board a J598 voltage regulator faulty (in short) as the s4 64A diodes that corresponds to this part of the circuit. Also the 3A fuse was blown and the zener ZD701 was shorted (thanks to billy66 that has made a good effort to discover for me the breackdown voltage).

2) I replaced everything, but the vga card has also a short, that I cannot isolate. I´ve removed all the caps that was on the shorted trail, hoping one was shorted but with no luck, if tboxxx allow me to use his pictures,

In red are the shorts (except the 3A fuse that was open). On the vga, afther replacing the big 950T (1,8V 1A regulator) I realiced the regulator wasn´t shorted. The other fet of the circuit wasn´t shorted either. (if someone knows a replacement just in case the nº is T044 / 950t65 the slash means new line)
On blue are something remarkable about what seems to be an eprom, that has 4 pins for ground (not corresponding to datasheet).
that´s all for now, if someone could please tell me what can I test, as I havent found datasheet for the FLI5961 nor the TW9606, and I´m running out of hopes here.
More to tell is that not a single zener of the vga card was shorted (on both ways), and the 5 pin stuff on the back of the vga says 69789 or 697B9 (can´t find datasheet or replacement but I think the short shouldn´t be there as both pads are linked with a cap that I removed and was ok).
Thanks for reading and any advice would be really apreciated!
Chad

PW: to tboxxx: your board seems to have a white residue, make me wonder if it has get wet or something.

[tboxxx]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

I am reading 0.1 ohms with TEK and Meterman. Meterman beeps on continuity test.
I will desolder both FD and check those.

[retiredcaps]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Okay, let's see if I put these puzzle together properly?

1) On pin 3 of J033, see if there is continuity to each negative part of FD 7/8 (the white stripe).

That is, put your multimeter on ohms. See if the ohms measurement is less than 1.0 ohms from pin 3 (yellow) of the voltage regulator to each diode (yellow again).

2) If yes, then I suspect the diodes could be bad. You will have to desolder both FD 7/8 and retest them out of circuit. If they test good, then I suspect the voltage regulator could be bad.

[tboxxx]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Another one is TEK DMM850, but it did not help a lot.
The readings are not stable and not even close to a nominal.

[tboxxx]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Oh, I see. I have another multimeter at work (not Mastercraft and Meterman). Will check with that one.

[retiredcaps]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

I reread the Meterman 37XR datasheet and it says 400uF. I thought it was 4000uF so the 0L readings make sense.

[tboxxx]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

I tried to measure caps "in circuit" on USB board, but every time I was getting 0L on my multimeter (tried black probe to a negative lead of the caps and vice versa).

[retiredcaps]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

J033 is 960T63

The datasheet is here

http://www.alldatasheet.com/datashee.../G960T63U.html

It looks like a 3.3V 1A low dropout regulator.

[tboxxx]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Question. What is the full part number for the J033 chip? I know it is a voltage regulator, but I don't know what the output should be to find a replacement.

J033 is 960T63

[retiredcaps]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Another idea I had is to use the Meterman 37XR to read the capacitance of the capacitors on the USB board. Set the 37XR to 4000uF

Let's measure everything "in circuit" first (no desoldering of things). For each cap on the USB board, report the following like the example below.

C123 - 470uF 25V, measures 3300uF
C145 - 330uF 25V, measures 333uF

I know some of these readings will not make sense because the capacitors could be in parallel and/or series and it is best to desolder them and measure them out of circuit, but let's start with "in circuit" first.

For measuring uF, put your black probe to the negative lead of the cap (the stripe) and red probe to the positive lead of the cap.

[retiredcaps]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Any ideas? What is the next step?

Those voltages look okay on the U connector.

I suspect J033 is bad. The possibilities are

1) J033 itself is bad.
2) The components (possibly capacitors) feeding the voltage to J033 are bad.

Question. What is the full part number for the J033 chip? I know it is a voltage regulator, but I don't know what the output should be to find a replacement.

[tboxxx]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

12 U shape contacts to Ground:

Contact Pair    |  Voltage
TP31        |  18.82V  
TP32        |  -0.01V  
TP33...TP36     |  3.32V...0.00V  
NoName (Ground)   |  0.00V  
TP34...TP37     |  0.03V...1.54V  
TP33...TP38(Ground) |  0.03V...-0.01V

Any ideas? What is the next step?
Thanks.

[retiredcaps]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Also, why two different meters shows different numbers?

Did some more research on this.

Some multimeters can read diode measurements up to 2.0V before showing 0L (out of range). My 2nd hand 20+ year old Fluke 75 is one of those multimeters.

For the Meterman 37XR, it looks like the threshold is 3.0V DC before it displays 0L as per

https://cdn.badcaps-static.com/pdfs/...dcfcdea073.pdf

[retiredcaps]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Unstable means the voltage changes from 1V to 3.5V all the time.

J023 and J032 look correct. 1.8V and 2.5V DC are "normal" output voltages for a voltage regulator (3.3V DC is another popular one). There is something wrong with voltage coming into J033. It should be a steady reading.

There is a 12 pin U shaped connector that connects the logic and USB board.

Number them 1-12 on the USB board anyway you like. VERY CAREFULLY, measure each pin and report the voltages. Put your multimeter on 20V DC. Do not let the red probe slip as you may cause a short. Put the black on a ground screw again.

[tboxxx]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

OK, here are the results:

Regulator |  G  |  O  |  I  |
J023   |  0V  | 1.79V |  3.32V |
J032   |  0V  | 2.49V |  3.32V |
J033   |  0V  | Unstable| Unstable|

Unstable means the voltage changes from 1V to 3.5V all the time.
J033 is the one on the USB board.

[tboxxx]

Re: Dell 2007FPb No Power, Power and 1 icon (VGA) blinking

Example of ground screw on each board circled in light blue.

I can see these screws. Should they be connected to the monitor metal base which is connected to yellow-green ground wire? In this case I cannot reach the pins of the regulators.