Dell E173FPf

[darkstar]

I have the monitor listed above. Nothing will come on the screen but i have a green light when its not plugged in and a orange light when i have it plugged into a computer. I have read through past forums and checked the srf10-10 diode and it seems to be fine.

[Bobdee]

Re: Dell E173FPf

Hello Darkstar
Check this out

https://www.badcaps.net/forum/showpo...8&postcount=20

the marking on the board is U851 for this IC, found by panel connection, check if you have continuity between,pins 3 + 5 if you have it is possible that it has gone down, I am waiting on confimation from Eduardo in a couple of hours, post back and let us know what reading you get please, and as soon as Eduardo lets me know I will let you know, thxs
bob

[darkstar]

Re: Dell E173FPf

Thank you for the help. Yes there is a connection between the pins. I have my meter set on ohms 200 and it is reading 00.3

[Bobdee]

Re: Dell E173FPf

sorry Darkstar
ater re reading your post

I have the monitor listed above. Nothing will come on the screen but i have a green light when its not plugged in and a orange light when i have it plugged into a computer. I have read through past forums and checked the srf10-10 diode and it seems to be fine.

its obvious that your problem is not same as mine as you get amber and green LED, but if you can make continuity check between 3 + 5 pins on U851 and post back what you get, it will be helpful, are you getting nothing at all coming on your screen when you turn it off/on ? do you get no input box showing,? can you see anything when you put a bright torch face on to screen? (in a darken room better) give more detail if possible,pictures of both sides of board would help techies if pos

thxs bob

[Bobdee]

Re: Dell E173FPf

Thank you for the help. Yes there is a connection between the pins. I have my meter set on ohms 200 and it is reading 00.3

thanks for that info, thats very helpful to me, it seems to me thats the way it should be,waiting on Eduardo's confirmation
bob


edit you might check your current resistor for cracks in middle section at r859 mines had it

[darkstar]

Re: Dell E173FPf

Yes there is continuity. My ohm meter is reading 00.3 when i put it on the the 3rd and 5th pin. Nothing at all comes on the screen, it is just black. I get the green light when the monitor is not plugged into the computer and the amber LED when i have it plugged into my computer. I am trying to get the pictures of the board uploaded but i am having problems getting them small enough so i will post them as soon as i can. Thanks again Bob.

[darkstar]

Re: Dell E173FPf

Here are the pictures for the board

[Bobdee]

Re: Dell E173FPf

Hello again Darkstar
Got my answer from Eduardo, not what I wanted to hear, looks like our IC 1506- 50 = AP1506 is kaput, it will pay you to read the whole thread that has Eduardo's answer in it, to make your own judgement, but also so as you can see problems with replacing this part,
The thread is

https://www.badcaps.net/forum/showthread.php?t=6533

You may have already read it, I have an idea how to get over some of the problems with some improvisation, I will get back to you on that, in the meantime, I have a load of various working monitors here, that i have repaired, and I am going to open them up until I find one with this IC and check it out, because I feel there is something that doesnt add up, so that, it will confirm to me one way or other, let me know what your thoughts are on it after you read thread and Answer
thxs bob

[EGuevarae]

Re: Dell E173FPf

Hello again Darkstar
Got my answer from Eduardo, not what I wanted to hear, looks like our IC 1506- 50 = AP1506 is kaput, it will pay you to read the whole thread that has Eduardo's answer in it, to make your own judgement, but also so as you can see problems with replacing this part,
The thread is

https://www.badcaps.net/forum/showthread.php?t=6533

You may have already read it, I have an idea how to get over some of the problems with some improvisation, I will get back to you on that, in the meantime, I have a load of various working monitors here, that i have repaired, and I am going to open them up until I find one with this IC and check it out, because I feel there is something that doesnt add up, so that, it will confirm to me one way or other, let me know what your thoughts are on it after you read thread and Answer
thxs bob

Guys, I don't want to mislead anyone. The questions Boobdee made yesterday are still going around in circles in my mind. So I went ahead and tore apart a working Planar Monitor that I remembered had the same IC.
** With my analog MM:
(-) on pin 3 (GND) I got:
330ohms to pin 5
335ohms to pin 4
335ohms to pin 2
Nothing to pin 1

(+) on pin 3 I got
Nothing to Pin 5
100,000 to Pin 4
500,000 to pin 2
Nothing to pin 1

with the DMM, on diode test mode:
(-) to pin 3 (GND)
No lectures

(+) to pin 3
691 to pin 5
660 to pin 4
700 to pin 2
nothing to pin 1

The bad I have has a reading of 0.9 ohms both ways between pins 1 and 3 *tested off circuit*. That's why I deducted it was bad (among other things) in the eMachines I have. It had the input DC pins reversed and died.
What I suggest is that you desolder the pins and test it that way, because if something forward the IC is shorted, you'll read short/low resistance between the pins, even if they are not shorted inside the IC itself. Seeing the block diagram below, I don't think that the IC should have that low resistance between pins in my particular case.

[darkstar]

Re: Dell E173FPf

Hello Bob,
I went back and read his post and from what I gather he said, is that I should not have continuity between pins 1 and 3 which I do not. If I have the power hooked up I get 12v off of the 1 and 3 pins but I do not get any volts off of the 3 and 5 pins. The 3 and 5 pins also read 0.3 off of the ohm meter. I'm still not sure if that is right or low. I think it might be kind of low if his was reading 0.9 I figure mine should be somewhere close.

[EGuevarae]

Re: Dell E173FPf

If I have the power hooked up I get 12v off of the 1 and 3 pins but I do not get any volts off of the 3 and 5 pins.

That is your Input Voltage (1) and Ground (3). That is normal.

.... but I do not get any volts off of the 3 and 5 pins

From 3 to 5 you should get voltage only if the signal to "turn on" the IC is received (SD is the start/shutdown as far as I can understand from the Datasheet). If there's a problem and the signal does not get to the SD pin, it will not "awake". I guess it is normal that you, in the condition the monitor is, don't have any V reading between 3 and 5.

And for the 0.9ohms reading on my IC, I don't think that is normal : Pin 5 (SD) has Voltage and pin 3 is ground, and there should not be that kind of low resistance between them. Is like if you take the two wires from a DC adapter (+ and -) and wire then together : not good, right?

I guess we should (all the three of us) wait, or ask for the help of one of the senior members like PCBONEZ, Davmax, and other people around here that has worked with electronics more in deep. Toasty had given me some good advice too.

But even if they don't confirm the IC issue (in my case), there's no way that, off circuit, those two pins have so low resistance between them, both ways.

As I said before, you should (if you suspect your ICs are bad) lift the pins and test them that way and see what you get. Maybe your problem is different and you are looking in the wrong place.

[darkstar]

Re: Dell E173FPf

I am not sure yet if I want to lift those pins. I don't want to do something and not be able to put it back. Is it difficult to solder those pins back on? My experience is guitar cables, pick ups, input jacks, and wires. Nothing really that small, so I am still debating.

So I put everything back together to see if I could see any kind of flash or any kind of light on the screen and now The green LED is not coming on. So I think i am moving backward here.

I guess i was also thinking, could it be back lights in the monitor? Do those go out? And is there a way to test for that kind of a problem? Or am I complete wrong in this area?

[EGuevarae]

Re: Dell E173FPf

Yes, the lamps could go. They are like regular fluorescent lamps, just smaller.
You can test them on another known good monitor, make a tester like the one I made from an internal neon kit for a case, or just put known good lamps in your inverter, but if you just have one LCD, it would be difficult. And if you are not sure about the pins, don't do it. I wasn't quite sure the first time, and you can see what I did to a good IC, so if not sure, don't do it. As for the green light gone, well, you have to see what have you done so far to the LCD and see what went wrong. I've seen other threads with this model of LCD.

And now I am positive that my faulty IC is not either your or Bobdee's case. Your problem is different.

[darkstar]

Re: Dell E173FPf

Ok, Well thank you for the help I will keep reading. I don't know what would have caused the green LED just to shut off. I haven't done anything but check ohms on things that i have been reading about.

I think i have another suspicion. That would be the diode above the yellow transformer on picture to up there. I read a thread that said to check the SRF10-10 and that one seemed to work fine but the other one i can't get an ohm reading for it. The numbers on it or 27611 or 1l I'm not quite sure about the last 2. Then below that set is another set 430036.
Thanks Justin

[Bobdee]

Re: Dell E173FPf

Hello again darkstar
Phew my head is swimming, but here goes,

17'' E173FPf board,
M/M on diode check
(-) to pin 3 (GRD)
5 pin nil ohms
4 pin .632 ohms
2 pin .632 ohms
1 pin .003 ohms

(+) to pin 3 (GRD)
5 pin nil ohms
4 pin .171 ohms
2 pin .171 ohms
1 pin .003 ohms

xxxxxxxxxxxxxxxxxxxx

15'' E153FPf board
M/M on diode check
(-) to pin 3 (GRD)
5 pin nil ohms
4 pin .636 ohms
2 pin .636 ohms
1 pin .oo3 ohms

(+) to pin 3 (GRD)
5 pin nil ohms
4 pin .156 ohms
2 pin .156 ohms
1 pin .003 ohms

all readings with AP1506 on board,

As I have said previously, I have had no reason to suspect my ICs because my 2 monitors are totaly dead at power up, no red or amber LED, also I have a burnt out current resistor on the PSU between mosfet souce and PWM controller, what took me down this road was mavericks thread,I understood it to say that if there is continuity from pin 5 and 3 then the IC is kaput and both of mine was that way, but after reading it again several more times, it is possible that they were saying the opposite, anyhow if your IC gives same readings as my 17'' then I would think they are ok,
But this is a bit over my head, I have taken the readings for those who know these things and can help out, can you check yours against mine and see how they stand up, and post back
thxs bob

and many thanks to Eduardo for cheking that IC and giving all that info, much appreciate your help

[Bobdee]

Re: Dell E173FPf

hello again
its not 27611 its 2761i its the mosfet that I mentioned in last post, heres datasheet,

http://pdf1.alldatasheet.com/datashe...AP2761I-A.html

bob

[darkstar]

Re: Dell E173FPf

Ok well after testing it multiple times this is what i came up with on my velleman DMM set to diode check or 2k on the ohm selector

(-) on P3
5 pin .000 ohms or 00.3 ohms if i set it to 200
4 pin 1.701 ohms
2 pin 1.705 ohms
1 pin 1 ohms

(+) on 3
5 pin .000 ohms or 00.3 ohms if set to 200
4 pin .201 ohms
2 pin .203 ohms
1 pin .293 ohms

I did not disconnect the pins from the board.

As far as the ap2761i if i put the (-) on g and (+) on s it starts at about .340 and slowly drops a number ever 2 to 4 seconds nothing happens if i put + on d or if i put (+) on g and touch the (-) to d or s

[Bobdee]

Re: Dell E173FPf

Hello again
Im baffled on those readouts, I dont know what to say,
as for the mosfet, I have read that you need them off the board to check them,and the voltage your meter gives out needs to be enough to charge them up some meters dont comply, you may know more than me,on this, but looking at mine it is soldered both sides of board, so care is required when removing, they can be damaged by overheating
bob

[EGuevarae]

Re: Dell E173FPf

Hello again darkstar
Phew my head is swimming, but here goes,

17'' E173FPf board,
M/M on diode check
(-) to pin 3 (GRD)
5 pin nil ohms

(+) to pin 3 (GRD)
5 pin nil ohms

xxxxxxxxxxxxxxxxxxxx

15'' E153FPf board
M/M on diode check
(-) to pin 3 (GRD)
5 pin nil ohms

(+) to pin 3 (GRD)
5 pin nil ohms

all readings with AP1506 on board,

Nil as in "no resistance, fully conductive", or Nil as in "No connection".
I got confused because I'm a developer and I/we use nil to denote a non existing/invalid value.

Anyway, I too believe that your problem is different. As I said (or at least, I tried to say...) in the eMachines thread, is that the guy that handed over the LCD to me connected the (-) and (+) DC input cables IN REVERSE, and the video board went straight to hell. Trying to revive it, I ended up with this
IC that, after lifting up the pins, was/is shorted on pins 1 & 3. The readings I presented were taken of working IC, same model, on a Planar PT1500. I can't mess up that much with that monitor because is a touchscreen in a POS system and I retired it just an hour to reopen it , relift the pins, retake the readings, resolder, reclose, retest, reinstall, and return (a lot of REs back there. Actually, It took me 1:15, but it was OK... not so much people in the store these days .....).

Again, I believe that your problem is different. But we can (any of the three of us) open up a new thread and specifically ask for one of the guru's help.
I am not that good with electronics. I'm a newbie with just good observation and deduction capabilities learning with a digital camera, pen and paper in one hand, and a soldering iron & multimeter in the other (well, not all of these at the same time, but you get the idea ....).
I'll have the board around, and will try to get another working one with the IC to try to answer any question you may have guys.

[darkstar]

Re: Dell E173FPf

Hey
Yes i am not sure what to think about those read outs either. I am hoping i don't have to remove anything off the board just yet. I don't want to damage anything that is not damaged. So i will have to wait on that. Well write back if you find anything else that will help. I will keep on reading.
Thanks for the help
Justin