Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

[CATPart]

My monitor instantaneously turned off when I was using it, with no symptoms before it happened. I took it apart to find a blown fuse. I replaced the fuse, plugged in the power supply, and the new fuse blew immediately. All of the capacitors on the board look perfect. What might be causing my fuse to blow?

[PlainBill]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

My monitor instantaneously turned off when I was using it, with no symptoms before it happened. I took it apart to find a blown fuse. I replaced the fuse, plugged in the power supply, and the new fuse blew immediately. All of the capacitors on the board look perfect. What might be causing my fuse to blow?

Short answer - a short.

A more helpful answer, probably a short in either the bridge rectifier or the power transistor.

Pictures of the front and back of the power supply will help. Read the thread in the FAQ entitled 'Inserting pictures in your posts'.

PlainBill

[EGuevarae]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

Short answer - a short.

[EGuevarae]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

...probably a short in either the bridge ...

I go for this one.

[RacerX]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

Going through the same problem with the same Gateway FPD2485W. Maybe we can kill two birds with one stone (thread). I already replaced all the caps on the power supply board (DigiKey), except the big 150uf/450V. Fuse blows immediately when power cord is plugged into the PB. Note to readers; there is no external power supply to these monitors, just a cord.

Power Board:


(All the purple caps were replaced after this picture was taken.)

As you guys mentioned, the problem is most likely a short blowing the fuse. Being a bit naive, where on this board should I check for the shortages? Rather than just "bridge rectifier or the power transistor", Can you point them out please?

I can take more pics if needed, just let me know specifically where...

Thanks for the time and help!

PS: Testing will be done with help of local electronics store tech.

[EGuevarae]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

Going through the same problem with the same Gateway FPD2485W. Maybe we can kill two birds with one stone (thread). I already replaced all the caps on the power supply board (DigiKey), except the big 150uf/450V. Fuse blows immediately when power cord is plugged into the PB. Note to readers; there is no external power supply to these monitors, just a cord.

Power Board:


(All the purple caps were replaced after this picture was taken.)

As you guys mentioned, the problem is most likely a short blowing the fuse. Being a bit naive, where on this board should I check for the shortages? Rather than just "bridge rectifier or the power transistor", Can you point them out please?

I can take more pics if needed, just let me know specifically where...

Thanks for the time and help!

PS: Testing will be done with help of local electronics store tech.

Bad picture.
Can you do a close up of the black "thing" at the right of the transformer?
Or can you confirm that is a black square-like component with four legs soldered to the board?
Or you can take the board to the local electronics tech. He should be able to tell you (and test) where the bridge rectifier is.

[mcfischer]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

I just fixed one an hour ago. Complaint was "Flashes and dies". Powered up and lit up the bulbs for several minutes until ... (quiet snap) then dead.
Fuse open. ohmmeter showed a short across the big cap. It was the smps FET had shorted. The BIG cap esr was over 100 ohms. Replaced big cap, FET and Fuse and all is good.
Mike

[JasonAmora]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

I just fixed one an hour ago. Complaint was "Flashes and dies". Powered up and lit up the bulbs for several minutes until ... (quiet snap) then dead.
Fuse open. ohmmeter showed a short across the big cap. It was the smps FET had shorted. The BIG cap esr was over 100 ohms. Replaced big cap, FET and Fuse and all is good.
Mike

I've been looking around the internet for weeks and still haven't found a solution. This, however seems closest to what I'm dealing with.

When I plug the cord into the power supply, theres a sound like one of the capacitors is dumping it's charge. I've replaced all the other ones BUT the big one in the middle of the board. I'm having trouble getting it OFF the board (power board) cause the glue that's holding it down, so I don't know what it's charge is to buy a proper replacement.

My theory is that either that big cap is bad or shorted, or that the fuse next to the ac-inlet is bad...

Long story short, I was wondering what capacitor you used as a replacement for the big one, and where did you get it? Also, what the other term means. FET? What is that?

Sorry, I know I'm a total n00b when it comes to this electronic stuff. I've been out of the loop for 8 years ><

[retiredcaps]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

When I plug the cord into the power supply, theres a sound like one of the capacitors is dumping it's charge. I've replaced all the other ones BUT the big one in the middle of the board. I'm having trouble getting it OFF the board (power board) cause the glue that's holding it down, so I don't know what it's charge is to buy a proper replacement.

My theory is that either that big cap is bad or shorted, or that the fuse next to the ac-inlet is bad...

Long story short, I was wondering what capacitor you used as a replacement for the big one, and where did you get it? Also, what the other term means. FET? What is that?

If you have a multimeter, you can quickly determine whether the fuse is open or not. A good fuse should measure 0.3 ohms.

If you need to cap the big capacitor, use an exacto knife to cut away the glue. The glue is used at the factory to hold the components in place until it is soldered.

A FET is short for mosfet.

[retiredcaps]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

My theory is that either that big cap is bad or shorted, or that the fuse next to the ac-inlet is bad...

Bridge rectifier could also be shorted if you are getting no power at all.

[JasonAmora]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

I get power. After about an hour of sitting there, it'll power up and whatever video source is currently feeding it is what comes up. But the panel control on the side doesn't work. Sometimes it does, sometimes it doesn't. It's extremely temperamental. I have it working somewhat right now, but it'd be nice to be secure in knowing that i can switch sources without consequence.

Forgive me, you're going to have to talk a bit stupider for me. A lot of the terms you're using I don't know what they are, what they do, or what they look like. Or what their relevance is to my debacle....

[Wrog]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

I've replaced all the other ones BUT the big one in the middle of the board. I'm having trouble getting it OFF the board (power board) cause the glue that's holding it down, so I don't know what it's charge is to buy a proper replacement.

My theory is that either that big cap is bad or shorted, or that the fuse next to the ac-inlet is bad...

Long story short, I was wondering what capacitor you used as a replacement for the big one, and where did you get it?

A couple of things -- if you've replaced all but the big caps, which did you use (brand/series, or where did you purchase them)? Not all capacitors are good replacements even if they have the same voltage/capacitance ratings (radio shack caps, for instance), and it could be contributing to some of the problems you are seeing.

For the big caps, either take pictures and post them so that someone can identify them, or list the make/model/series (and diameter/height). Putting your location in your profile will help someone suggest a place to purchase them, or you can check the FAQ here in the forums for a list of good places to buy.

[Wrog]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

I get power. After about an hour of sitting there, it'll power up and whatever video source is currently feeding it is what comes up. But the panel control on the side doesn't work. Sometimes it does, sometimes it doesn't. It's extremely temperamental. I have it working somewhat right now, but it'd be nice to be secure in knowing that i can switch sources without consequence.

Could be a regulator that's shot. Post pictures of the logic (main) board and someone can point out where they are and how to test them. When you say the panel control doesn't work, do you mean you don't get any lights? Do the touch controls not respond? Do they light up and then go away? Are they red, purple or blue? Specifics would help diagnose.

Forgive me, you're going to have to talk a bit stupider for me. A lot of the terms you're using I don't know what they are, what they do, or what they look like. Or what their relevance is to my debacle....

Read, read, read and then read some more. The only way to really understand is to take it all in and then ask questions. There are tons of highly skilled folks here who love to share their knowledge. If something doesn't make sense, or if you want to know how to do something, by all means ask! For instance, testing a fuse: a continuity test with determine if it's good or not. Put your multimeter on resistance setting, and touch each end of the fuse (doesn't matter which direction). High reading (open) means it's bad, low (near 0) means that it's good.

EDIT: Forgot to mention -- posting pictures of your board(s) along with as much detail as possible is the fastest way to get help. It's much easier to point to a picture than it is to describe something.

[JasonAmora]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

Ok, I'm retarded. I don't know how to post pictures on here. I've tried that attachment thingy below the reply box, but it's not working for me at all.. Any help?

[retiredcaps]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

I don't know how to post pictures on here. I've tried that attachment thingy below the reply box, but it's not working for me at all.. Any help?

That is the correct way to attach, but your picture has to be less than 2000x2000. See

https://www.badcaps.net/forum/showthread.php?t=1868

[Wrog]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

I don't know how to post pictures on here. I've tried that attachment thingy below the reply box, but it's not working for me at all.. Any help?

Definitely follow the link that retiredcaps provided on how to attach pics. Also keep in mind the quality of info that you give affects the quality of help you get. Using this topic as an example, you should give more specifics about what's not working... Are you getting some sort of error message?

[JasonAmora]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

Well, my computer is retarded I suppose, since I've tried 3 different web browsers and different file extensions and it STILL won't work. Yes, the images are smaller than 2000x2000px So I'm uploading them to a third party and will link them as I go along.


I've had this monitor for well over a year now, and it's always been the same since I got it. I can get it to work, IF the video source is on and feeding it, AND if i can plug it just right. I used to have to plug the cord in the back of the monitor at certain angles and listen for a specific pattern in the electric shock to get it to turn on. Now, i've lost my patience with doing that so I let it sit there for an hour and wait for it to decide to turn on.

Afterwards, whatever video source was plugged in must stay on or the monitor wigs out. If I want to turn off the source, I.E. a computer or my Xbox, i'd first have to press the blue power button on the side touch panel, wait 10-20 seconds for the monitor to decide to turn off, THEN turn off the computer or xbox.. If i wanted it to keep working, i'd have to make sure that the computer or xbox was on beFORE i turned the monitor back on.

So that's really my main problem. It'll power up after a while, but the touch panel controls lag beyond all reason. If i press the menu button above the power button, it'll wait 40 seconds, then think i'd held it down, pulling up the product tour, rather than the main menu. Then to get it to go away, i had to wait another minute before the touch panel would respond to touch again, THEN press the "exit menu" button...

All in all, it's extremely temperamental.

Now. I've replaced all THESE capacitors in the picture below.

http://img265.*************/img265/3264/replaced.jpg



That didn't fix anything.


So here are my thoughts.

When I plug it in and listen closely, it sounds like the power shorts out somewhere ON the power board. Somewhere around HERE.

http://img195.*************/img195/6264/suspectq.jpg


So it's either this transformer:

http://img52.*************/img52/2698/transformer.jpg


This fuse:

http://img514.*************/img514/2861/fusea.jpg


Or any ONE of these things I don't know what they are.


http://img690.*************/i/redcapunkown.jpg/
http://img148.*************/i/coilsunknown.jpg/
http://img294.*************/i/blackboxunkown.jpg/


I've ordered a replacement fuse and we'll see what happens when i replace it. But other than that, I don't know what else to say. I think the problem mostly has to do with the power board, not the inverter or the processor board. Cause it's obvious the sound is coming from the power board. I've removed it from the monitor entirely and carefully plugged it in, so i know for sure there's a problem THERE.

Beyond that, I'm clueless..


Was that descriptive enough? Or do you need more?

[retiredcaps]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

I've had this monitor for well over a year now, and it's always been the same since I got it. I can get it to work, IF the video source is on and feeding it, AND if i can plug it just right. I used to have to plug the cord in the back of the monitor at certain angles and listen for a specific pattern in the electric shock to get it to turn on.

You could have bad/cold/poor solder joints on the backside of your powerboard. If you flip over the powerboard, look at the solder right at the AC input.

See what good/bad joints look like at

http://workmanship.nasa.gov/lib/insp...uirements.html

So that's really my main problem. It'll power up after a while, but the touch panel controls lag beyond all reason. If i press the menu button above the power button, it'll wait 40 seconds, then think i'd held it down, pulling up the product tour, rather than the main menu. Then to get it to go away, i had to wait another minute before the touch panel would respond to touch again, THEN press the "exit menu" button...

The menu functionality is controlled by the chip on the logic board (green color). We need a picture of that (top and bottom). The main chip could be poorly soldered or overheating?

All in all, it's extremely temperamental.

Now. I've replaced all THESE capacitors in the picture below.

Are they Panasonic FM caps?

When I plug it in and listen closely, it sounds like the power shorts out somewhere ON the power board. Somewhere around HERE.

Check for poor/bad solder joints. Post a clear focused picture of the backside with a closeup of this area.

I've ordered a replacement fuse and we'll see what happens when i replace it.

It is unlikely to be your fuse. If the fuse is bad, you would not get any power at all.

PS. JPEG files are limited to 2000x2000 and 1.91MB which is why your photos won't upload. Right underneath the upload button is a grid of the file types, their max size and dimensions.

[retiredcaps]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

I've ordered a replacement fuse and we'll see what happens when i replace it.

Also check the fuse soldering.

[JasonAmora]

Re: Gateway FPD2485W 24" LCD Fuse Blown, caps the cause?

PS. JPEG files are limited to 2000x2000 and 1.91MB which is why your photos won't upload. Right underneath the upload button is a grid of the file types, their max size and dimensions.

Well, my computer is retarded I suppose, since I've tried 3 different web browsers and different file extensions and it STILL won't work. Yes, the images are smaller than 2000x2000px So I'm uploading them to a third party and will link them as I go along.

However, I forgot to pay attention to the file size. Sorry.

I left the images HUGE this time so you can see it up close. Sorry if that's a problem.

Top Side of Logic Board:
http://img208.*************/img208/3773/0000295.jpg

Underside of Logic Board:
http://img814.*************/img814/9801/0000297.jpg


There's no obvious signs of any damage or improperly soldered parts on either the power board OR the logic board.

I've heard tell of a component going bad on the logic board though that causes the touch panel to respond slowly. It's some kind of a timer or limiter next to where the ribbon cable plugs in.

Shown HERE:
http://img121.*************/img121/3964/logicboard.jpg


I don't remember what they're called, but if it's possible they're the problem, that'd be good to know..




Thanks again for you help...