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

[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....

[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.

[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.

[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 ><

[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

[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.

[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?

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

I go for this one.

[EGuevarae]

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

Short answer - a short.

[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

[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?