Dell W1700 LCD Rev00

[marketta]

Re: Dell W1700 LCD Rev00

hi Jhon
I am Italian and I have ordered the inveter to LCD REPAIR in America
you/they have sent him/it yesterday.
I am happy that you have mended your Monitor, and I hope that so it will be for me.
I have noticed during the reparation of the inverter that you/they should also be replaced Q80-Q81-Q40-Q41 after having replaced F1-F2-C80-C43 and everything it returns that is as before that the monitor works.
Now aspect that the inverter arrives to me and then I will make you know
Hi to all of you and
thanks
Mario from the Italy

[marketta]

Re: Dell W1700 LCD Rev00

I Thank You For The Wishes Of Happy Birthday
A Thanks Of Heart
Marketta

[PCBONEZ]

Re: Dell W1700 LCD Rev00

cnaegeli - yes, usually

ebrentnelson - yes, usually

The backlight concept is simple. (Few parts.)

Power to the Inverter.
The Inverter makes high freq high volts AC. (Usually around 900-1400 volts).
The high volts connects to and lights up the CCL. (Cold Cathode Lamp.)

The CCL is basically a florescent light bulb that doesn't get hot.
It uses a different gas that needs the high volts to make it glow.

The backlight circuit has nothing to do with the image circuit, but, without a backlight you can't see the image even if it's there.

~~~

On for a few seconds and then goes out..

Inverters usually run at a higher voltage for a few seconds to initially start the lamp(s) and then kick down to the normal running voltage.
It may be the kick is working but the normal isn't.

Also have you tried lighting different tubes with the inverter?
(Tubes go bad too.)

.

[davmax]

Re: Dell W1700 LCD Rev00

The momentary backlight can be related to protection circuitry latching in and stopping the backlight inverters. Many designs do not have very fast (microsecond) protection.

For the record. The lamps are more correctly CCFL (Cold Cathode Fluorescent Lamps). Google CCFL.

The lamps in the FP737s LCD monitor consume 4.3watts each and there are four. They do get warm. Cold cathode can be confused with temperature. The cold relates to the fact that there is no heated cathode (to emit electrons) as in conventional fluorescent tubes. The backlights in LCD TV can consume a lot of power and generate heat, there is a move to OLED (Organic LED)technology to improve power consumption and display response (no backlighting).
http://www.audioholics.com/education...the-next-trend

[PCBONEZ]

Re: Dell W1700 LCD Rev00

Yes:
>> The cold relates to the fact that there is no heated cathode <<

Not heated,,, hence,,, it doesn't get hot. (as hot)

I'm laughing now.
.

[davetech]

Re: Dell W1700 LCD Rev00

hi Jhon
I am Italian and I have ordered the inveter to LCD REPAIR in America
you/they have sent him/it yesterday.
I am happy that you have mended your Monitor, and I hope that so it will be for me.
I have noticed during the reparation of the inverter that you/they should also be replaced Q80-Q81-Q40-Q41 after having replaced F1-F2-C80-C43 and everything it returns that is as before that the monitor works.
Now aspect that the inverter arrives to me and then I will make you know
Hi to all of you and
thanks
Mario from the Italy

Mario
can you look at the transistors Q 80 81 40 41 on the new board when it comes in and tell me what the markings are? the company that sells it says that they have a better version and that it should last a good while. i am wondering if they replaced the transisters as a precaution.


thanks

dave

[marketta]

Re: Dell W1700 LCD Rev00

I Have Answered You In Private

[Chadzero]

Re: Dell W1700 LCD Rev00

I'm having an interesting problem with my W1700. It still works, and I'm having sound, but I'm getting what looks like green static in place of a certain black hue. Also, there is a blue static that can be seen if you look closely at some of the blues. Note: This problem will go away for a few days if I transport the TV somewhere, but it slowly comes back and gets worse.

Here is a picture of the problem, it is slightly exaggerated.


This is kinda driving me crazy! Is this a problem caused by one of the boards? Maybe a grounding issue? I haven't taken it apart yet to check for damaged components, so some direction would be greatly appreciated.

[Krankshaft]

Re: Dell W1700 LCD Rev00

If moving it makes it go away then you most likely have a bad solder joint in one of the video sections.

But first before checkign for that try unplugging and reseating all of the connectors inside the TV including the video board to LCD connector. You don't want to be hunting for something that isn't there if its just a bad cable connection.

The only way to find a cracked solder joint is to first examine the video board closely checking every IC leg, SMT, and through hole component for the finest of solder joint cracks.

This is time consuming but it always works for me and you get better with practice. If you don't have good eyes be sure to use a magnifying glass.

You must really look slowly and carefully. I got a Panasonic 27" TV for $10.00 because it intermittently shut down due to a bad solder joint on one of the NPN transistors.

I also fixed one of my Sharps that shut down intermittently as well from a bad solder joint on a 3 pin microcontroller reset IC.

After my arm got tired of whacking it to turn it on like the Fonz I went in and repaired it .

Here are pics of the cracked joints on the Panasonic and the Sharp I've attached them. Look very closely to the circled areas download and enlarge the pics if you have to.

Knowing what you're looking for is half the battle.

These cracks were on through hole components but the cracks on SMT will be the same.

If the component is through hole put your finger on it and wiggle it if the leads on the other side move the joint is cracked.

If the leads don't move and the solder looks suspect touch it up anyways.

If that doesn't work get a wood dowel and power the TV up and start applying light pressure to the board to narrow the area of failure down.

[Chadzero]

Re: Dell W1700 LCD Rev00

Thanks for the advise, I'll try taking it apart this weekend. I'll post some pics if I find anything.

[PCBONEZ]

Re: Dell W1700 LCD Rev00

Chadzero

Krankshaft makes a good suggestion.
Your initial thought that it's a grounding issue is valid as well.
Also possibly a LACK of grounding problem.

Lets say a static ground is loose or lifted. (Not making a good connection.)
Static builds up and cruddies the picture.
While moving it something shifts, connects, and makes the ground. (Bleeding off the static.)
Then when you set it up again the static builds up again.

Follow?
.

[Chadzero]

Re: Dell W1700 LCD Rev00

Well I took some initiative and took it apart yesterday. Ripped all the boards out. All of the components checked out alright, solders looked ok. Then I glanced over the cable that connects the main video board to the board on the back of the LCD itself. It appeared to be not seated all of the way! This wire had multiple color wires and a few ground wires, so this might have been causing my problem.

I reassembled eveything after looking for further problems and not finding any, I put everything back together. It works fine now, so we'll see if any static builds up. I'm keeping my fingers crossed. Thanks again for the help guys, much appreciated.

[Krankshaft]

Re: Dell W1700 LCD Rev00

We're glad to help.

[marketta]

Re: Dell W1700 LCD Rev00

Mario
can you look at the transistors Q 80 81 40 41 on the new board when it comes in and tell me what the markings are? the company that sells it says that they have a better version and that it should last a good while. i am wondering if they replaced the transisters as a precaution.


thanks

dave

Hi nothing has not arrived in still italy
I report me to the inverter for the dell w1700
mario

[marketta]

Re: Dell W1700 LCD Rev00

hi Dave I am Mario
Today you/he/she has finally arrived in Italy the inverter paid Ambit T501045.00 49,99$+16,50 $
The components that you ask me and that is Q80-81-40-41 is not changed they are always 4600.
I want to give you an information to respect the supplier of the inverter www.LCDREPAIR.US
it is a little serious I make sense of me:
1) the inverter that you/they have sent me to arrive in Italy has employed 1,5 months
2) the inverter is a broken inverter mended by www.LcdRepair.US
3) on the inverter Q80-81-40-41 has been replaced; C80-43;
4) as it regards the two fuseses F1-F2 I/you/they have been replaced (short-circuited) with two drops of welding, a very DANGEROUS thing the inverter in that way is not protected from Dangerous fuses.
5) VERY BAD WELDINGS DONE FROM INEXPERIENCED ALL DIRTY TRACCIES DI SCORCHES OF BURSTED COMPONENTS
I don't now have trust of www.LcdRepair anymore.US to which I have sent a lot of email and anchor I have not had answered.
Dave I ask you, where can I find Q80-81-40-41? do you give me the address of some site where I can purchase them?
Dave www.lcdrepair.us has told you a buggia and to me you/he/she has sold an inverter used not a new inverter.
Don't purchase from www.lcdrepair.us
hi
make to know me
a regard
mario

[marketta]

Re: Dell W1700 LCD Rev00

Dave I have Attached The Photos If you can See her
The Card is Now' all Cleaned By Me, Observes The Two fuses F1-F2

[davetech]

Re: Dell W1700 LCD Rev00

i see the fuses and i don't know why thery are soldered over. i would send them an email with the pictures attached and asked why is f1 and f2 mising.

i don't know of any other place that sells the replacement. if you can't get threw to the company, i will be more that happy to send them an email.

please let me know.



dave

[davetech]

Re: Dell W1700 LCD Rev00

mario
use this link

customerservice@lcdrepair.us


dave

[kc8adu]

Re: Dell W1700 LCD Rev00

Dave I have Attached The Photos If you can See her
The Card is Now' all Cleaned By Me, Observes The Two fuses F1-F2

yikes!
if you have a short now hope the psu shuts down.or install fire suppression system!

[marketta]

Re: Dell W1700 LCD Rev00

thanks Dave
I have already sent numerous email without any answer from lcd.repair
and I don't know the motive because you/they have eliminated the fuseses.
I thank the joky tone of kc8adu we hope that nothing doesn't happen because I agree with you, I will have to install a station fireproof (firemen).
I cross the fingers and when I will install him I will beg God and I will do me the sign of the cross
I will make you know
thanks to you
mario