Dell LCD E198WFPF no power

[PlainBill]

Re: Dell LCD E198WFPF no power

reinitializing the EEPROM?
Sounds like some special programming device is needed.

As I noted earlier, I have the identical problem with a Dell E177FPf. The power LED does not come on, and there is no CCFL activity. Here are the results so far:
Main power supply output - good
Physical appearance and ESR of all caps - good
Outputs of on-board regulators - good
Crystal for processor - oscillating
Signals from front panel buttons - good.

This monitor has only three ICs in the 'logic card' section, a gm2621-LF, a 24C02WI, and a Pm25LV010. It appears the Pm25LV010 holds the firmware, and of course the 24C02WI holds user settings. I've got a replacement on order for the 24C02 and will see if by some slim chance that fixes the problem.

PlainBill

[albertwong]

Re: Dell LCD E198WFPF no power

Would be very (VEEEEERYYYYYY) difficult

That sounds like impossible to get it.

[albertwong]

Re: Dell LCD E198WFPF no power

As I noted earlier, I have the identical problem with a Dell E177FPf. The power LED does not come on, and there is no CCFL activity. Here are the results so far:
Main power supply output - good
Physical appearance and ESR of all caps - good
Outputs of on-board regulators - good
Crystal for processor - oscillating
Signals from front panel buttons - good.

This monitor has only three ICs in the 'logic card' section, a gm2621-LF, a 24C02WI, and a Pm25LV010. It appears the Pm25LV010 holds the firmware, and of course the 24C02WI holds user settings. I've got a replacement on order for the 24C02 and will see if by some slim chance that fixes the problem.

PlainBill

I purchased another logic board. However, when I put in, the screen has vertial white lines instead of normal display. So is it not the problem of the logic board? I will take a picture of it tonight.

[albertwong]

Re: Dell LCD E198WFPF no power

I plug in the new logic board and found out that the display is a blank white screen.
I tried connecting to my computer and still the same.
It is like the flex cable was not connected.
The power indicator light is green though.

[PlainBill]

Re: Dell LCD E198WFPF no power

I plug in the new logic board and found out that the display is a blank white screen.
I tried connecting to my computer and still the same.
It is like the flex cable was not connected.
The power indicator light is green though.

A white screen is usually caused by an open fuse on the panel or a cable that is not properly seated. Also, check the pins at the lower end of CN106 (the connector to the panel). I'm sure power to the panel is on some of those pins.

PlainBill

[albertwong]

Re: Dell LCD E198WFPF no power

What is the power suppose to be on CN106?
5V?
If it is an open fuse on the panel, is it fixable?

[PlainBill]

Re: Dell LCD E198WFPF no power

What is the power suppose to be on CN106?
5V?
If it is an open fuse on the panel, is it fixable?

It depends on the panel; probably 5 volts.

The fuse can be replaced; however it may have blown because something else was shorted.

PlainBill

[albertwong]

Re: Dell LCD E198WFPF no power

from pin1 of the connector to panel:
4.92
4.92
4.92
0
0.01
0.02
0.01
1.14
1.34
1.24
1.21
1.18
1.31
0.01
1.16
1.33
0.02
1.14
1.34
1.14
1.33
1.24
1.22
0.02
1.17
1.32
1.14
1.33
0.42
0.01

Is it normal?
It got the 5V though.
Where should I check for the open fuse on the panel?

[albertwong]

Re: Dell LCD E198WFPF no power

I opened up the panel and checked F1. It is good.
What else can i checked?

[aubrey52]

Re: Dell LCD E198WFPF no power

if you have no power ck diode d851 on power/invert board. remove from board
FR107m is same fr107
Description: 1000 V, 1 A, fast recovery diode
Manufacturer:
Package: DO-41
Pins: 2
checked the power/inverter board.
resolder all round invert Transformer you have some bad solder on connt
thanks
and i hop this help i just fix monitor by doing this
Aubrey52

[albertwong]

Re: Dell LCD E198WFPF no power

if you have no power ck diode d851 on power/invert board. remove from board
FR107m is same fr107
Description: 1000 V, 1 A, fast recovery diode
Manufacturer:
Package: DO-41
Pins: 2
checked the power/inverter board.
resolder all round invert Transformer you have some bad solder on connt
thanks
and i hop this help i just fix monitor by doing this
Aubrey52

Thx. I will try that. So what problem your monitor was experiencing? Do you have the same monitor?

[PlainBill]

Re: Dell LCD E198WFPF no power

Thx. I will try that. So what problem your monitor was experiencing? Do you have the same monitor?

This is a waste of time and effort for your problem. Aubrey52 described a fix for a dead power supply. Your power supply is working.

PlainBill

[aubrey52]

Re: Dell LCD E198WFPF no power

PlainBill did he not say this on page 1 Dell LCD E198WFPF with no power, not even the green power light on the monitor.
albertwong said
he also said that I purchased another logic board. However, when I put in, the screen has vertial white lines instead of normal display. So is it not the problem of the logic board? I will take a picture of it tonight.
albertwong said
i do know that PlainBill is very good man
help me befor parts

what i am saying put your old logic board back in montor. ck what i said
your makeing more problem. by use differ logic board.
i don/t thanks it your logic board.
what bill said is right is for powersuppy and inverted board. and thank you haveing same thining happening.
went fine fix let me know
have a good
Aubrey52
just ck it d851 if read 2 ohm both way it bad
good luck

[PlainBill]

Re: Dell LCD E198WFPF no power

PlainBill did he not say this on page 1 Dell LCD E198WFPF with no power, not even the green power light on the monitor.
albertwong said
he also said that I purchased another logic board. However, when I put in, the screen has vertial white lines instead of normal display. So is it not the problem of the logic board? I will take a picture of it tonight.
albertwong said
i do know that PlainBill is very good man
help me befor parts

what i am saying put your old logic board back in montor. ck what i said
your makeing more problem. by use differ logic board.
i don/t thanks it your logic board.
what bill said is right is for powersuppy and inverted board. and thank you haveing same thining happening.
went fine fix let me know
have a good
Aubrey52
just ck it d851 if read 2 ohm both way it bad
good luck

Look at this post. Albertwong found a 5 volt output from the power supply. That same voltage is found on the logic card, as well as other voltages used by the processor. That shows the power supply is working.

One of the biggest mistakes amateurs make is believing all instances of a problem must have the same cause. You saw 'no power' and acted like every case of 'no power' must be caused by a shorted diode. If you think about it, you will realise how foolish that idea was. Let's make a short list of possible causes for that problem:

1. Electrical outlet dead.
2. Power cord not plugged into the outlet.
3. Power cord not plugged into the monitor fully.
4. Blown input fuse in monitor
5. Blown NTC
6. Startup capacitor for the SMPS controller bad
7. Bad solder joint on the power connector on the monitor.
8. Bad main filter cap.
9. Blown output fuse in power supply.
10 Bad output caps in power supply.
11. And there are even more reasons involving shorted diodes, transistors, open fuses, etc.

I'm sure you mean well, but you don't understand how the power led on a monitor works. Think about how a monitor works.

You plug in the power cord, but not the video cable. The power light goes green, (or blue). A message appears on the screen - "No signal". A few seconds later the screen goes black and the power LED turns orange.

You push the power button. Now the power LED turns off.

You push the power button again. The power LED goes green or blue, the 'no signal' message appears again, and again after a few seconds the screen black and the power LEE goes orange.

You hook it up to a computer and turn the computer on. Now the power LED turns green (or blue) and you see the POST messages as the computer boots.

If you looked at the schematic for any monitor you would see that the power led is controlled my the video processor. So a 'Not even a power LED' problem can mean a bad power supply, or it can mean a problem on the logic card.

PlainBill

[aubrey52]

Re: Dell LCD E198WFPF no power

Hi
PlainBill
thanks you
very much for help; i sure it will help me download road.
i do know one thing that power suppy is not only items that can be bad.
i was trying help him best i could. this why don,t ask for help on line to much
your are a good man bill. i sure do thanks you
for all your help.
Aubrey52
have a very good day went fine out what bad in montor you are working on
17" dell let me know. i sure don;t have all parts you do.
i thank you are very good man. yes lcd are litte new to me.i was a repair man
on vcr and tv set day gone for that.do know how startup work lcd for have book on this. and how repair lcd montor.

[albertwong]

Re: Dell LCD E198WFPF no power

aubrey52. Thank you for your help. Unfortunately, the information is not helping in this case. However, I am sure if you keep up the good work, you will be able to help other people.

[aubrey52]

Re: Dell LCD E198WFPF no power

Hi
albertwong.
your very welcome. i do know more what some thanks i do.
i build my owen computer i work on laptop and disk top.
i fix lot montor .and not one have come back.
so best for me just let rest do all helping on here.
just let me know what you find out went you fixing your montor. really hop some one on here can help you get it working
have a good day
Aubrey52
try to send you a email won;t work
good luck

[albertwong]

Re: Dell LCD E198WFPF no power

I found a service manual for E178wfpc.
It could be similar.
Does anyone have any idea?