FPD1760 700g

[merkin]

Damn you guys never cease to amaze me.

This time I got a Gateway FPD1760.

Here is a video of the problem h++p://rapidshare.com/files/442490017/100_0103.MOV, although it is hard to see in the video so here is the explanation:
The picture is shaky and fuzzy an unstable. Turning the refresh rate up makes the problem worse. It does NOT happen to the OSD or menu built into the display. So its definately the incoming signal, but the same computer and cable works fine on three other monitors.

Its probably a power supply issue as noted by other threads with the same monitor or similar (900g).

What I need help with is disassembly. Does anyone have a service manual or any tips. I tried for about 15 minutes and got nowhere. It feels like the plastic bezel is going to break if I pry any harder.

Thanks in advance.

-merkin

[digge]

Re: FPD1760 700g

Hard to help with disassembly without any good pictures of the monitor itself. Take a few good pics front and back of the monitor if its hard to open and I'm sure someone could give some hints. Many times it helps to remove what you can, for instance screws might be hiding behind the foot, behind rubber pads or under stickers. Once you get into it, get some good pics of the boards if you need help with identifying the problem itself. My guess is that you're right, that some kind of filtering doesn't quite work, or some kind of grounding problem.

[PlainBill]

Re: FPD1760 700g

IIRC, this model is what I describe as a 'front loader'. What you do is separate the two halfs of the bezel enough to slide a thin piece of plastic between them, then work your way around the case with another. Be very careful around the button area.

What kind of plastic? I prefer guitar picks, others use old credit cards, even a thin bladed screwdriver (or two) will work.

This monitor, is notorious for bad caps. Replace ALL of them in the power supply. You may have to replace those on the signal card (logic card) too.

PlainBill

[merkin]

Re: FPD1760 700g

Well I had better luck in round 2, but lost a few plastic tabs. oh well.

Here are pics


Uploaded with *************


Uploaded with *************

No visible signs or bad smells.
The 'lytic cluster in the top right of the PSU are
x3 KZE 10v 1000uf
x1 KZE 16v 330uf
x1 ELITE 50v 1uf
The two on the DC side of each Transformer for CCFL are
KY 25v 220uf

The three on the top right of video board are
x2 ELITE 25v 220uf
x1 ELITE 16v 220uf

Should I change every capacitor or just the bigger 'lytics with vents?

I have a FLUKE 87V for measuring.

Thanks

[EGuevarae]

Re: FPD1760 700g

What kind of plastic? I prefer guitar picks

That's what I use. They leave no marks on the units

[retiredcaps]

Re: FPD1760 700g

Here are pics

Please follow the instructional links in PlainBill's signature to post pictures. Please do not post pictures inline.

[merkin]

Re: FPD1760 700g

Please follow the instructional links in PlainBill's signature to post pictures. Please do not post pictures inline.

fixed here.

Also reupped video h++p://www.mediafire.com/?f68bcwum9d4kjzn

Again if anyone can help the problem is the pixels are not stable. They dance around, looks like an interference issue.

I originally blamed the PSU, but I powered up the video board with seperate power (I kept the CCFL's powered with the original power supply) (the 10-pin header has (x2)12v (x2)5v (x4)gnd Von/off and Vadj), but still have the same issue.

So by process of elimination, it is either the video board or
the CCFL connections from the original PSU.

Could it be the CCFL's or the frequency? I can measure Hz setting on the multimeter like here http://www.fonerbooks.com/test.htm. What is ideal number for this screen???

If I start replacing caps on the video board should I replace all caps, just the 'lytics, or just the 'lytics with vents?

Please help.

[jetadm123]

Re: FPD1760 700g

fixed here.

Also reupped video h++p://www.mediafire.com/?f68bcwum9d4kjzn

Again if anyone can help the problem is the pixels are not stable. They dance around, looks like an interference issue.

I originally blamed the PSU, but I powered up the video board with seperate power (I kept the CCFL's powered with the original power supply) (the 10-pin header has (x2)12v (x2)5v (x4)gnd Von/off and Vadj), but still have the same issue.

So by process of elimination, it is either the video board or
the CCFL connections from the original PSU.

Could it be the CCFL's or the frequency? I can measure Hz setting on the multimeter like here http://www.fonerbooks.com/test.htm. What is ideal number for this screen???

If I start replacing caps on the video board should I replace all caps, just the 'lytics, or just the 'lytics with vents?

Please help.

I would start by measuring the output voltage of the voltage regulators located on the lower left side of your board. I believe these are the two 3-pin devices with their upper tab soldered directly to the logic board. With respect to ground, measure voltages of all 3-pins and supply part numbers for each device.

If the output voltages are good, then I would start replacing the larger caps values first.

[merkin]

Re: FPD1760 700g

I would start by measuring the output voltage of the voltage regulators located on the lower left side of your board. I believe these are the two 3-pin devices with their upper tab soldered directly to the logic board. With respect to ground, measure voltages of all 3-pins and supply part numbers for each device.

If the output voltages are good, then I would start replacing the larger caps values first.

Cant find datasheets, but the part numbers are enough.

Closest to the DVI port and from left to right we have...
"5DGL
17-18L"
1. 4.955vdc
2. 1.800vdc (also tab)
3. gnd

"5FSL
17-33L"
1. 5.214vdc
2. 3.295vdc (also tab)
3. gnd

The cluster of 'lytics by the regulators are G-LUXON
2x 16v 100uf
7x 16v 10uf

The three vented ones are ELITE
2x 25v 220uf
1x 16v 220uf

I am stumped.

Should I Connect some powered laptop lcd inverters to power the CCFL's to completely rule out the PSU?
The pixels do become even more active as the monitor "warms up".

Or can I narrow it down to the the i/o ot the video chip (TSU56AK), but I cant find a datasheet for that either.
Also I have yet to mention the problem happens on both digital and analog inputs.

Thanks for the help ;-)

[jetadm123]

Re: FPD1760 700g

Cant find datasheets, but the part numbers are enough.

Closest to the DVI port and from left to right we have...
"5DGL
17-18L"
1. 4.955vdc
2. 1.800vdc (also tab)
3. gnd

"5FSL
17-33L"
1. 5.214vdc
2. 3.295vdc (also tab)
3. gnd

The cluster of 'lytics by the regulators are G-LUXON
2x 16v 100uf
7x 16v 10uf

The three vented ones are ELITE
2x 25v 220uf
1x 16v 220uf

I am stumped.

Should I Connect some powered laptop lcd inverters to power the CCFL's to completely rule out the PSU?
The pixels do become even more active as the monitor "warms up".

Or can I narrow it down to the the i/o ot the video chip (TSU56AK), but I cant find a datasheet for that either.
Also I have yet to mention the problem happens on both digital and analog inputs.

Thanks for the help ;-)

The 3.3V and 1.8V outputs look good. Since you tried powering up the logic board using different power sources with the same results and unless you're power supply output voltages are fluctuating, too low or high, it looks like you isolated the problem to the logic board.

Because of the logic board's smaller footprint, the manufacturer has to use physically smaller caps. This involves cramming a large cap value into a small can, which can dry out more quickly. Luxon and Elite have poor records and I would first try replacing the 220's followed by the 100's. Of course, it's your choice.

Also, I agree with PlainBill that the power supply onthis model is notorius for bad caps. Even if the output voltages check good, consider replacing all the smaller caps,except for the large 450V one.

[merkin]

Re: FPD1760 700g

.... unless you're power supply output voltages are fluctuating, too low or high, it looks like you isolated the problem to the logic board.

Since the board needed +12 and+5 volts I thought it would be a no brainer to use a PC PSU.

... I would first try replacing the 220's followed by the 100's. Of course, it's your choice.

I am in debt to you. what is you paypal? ill buy ya a beer-cheers

Replaced all the polarized caps on the video board and everything works!!!

I tested each one with my capacitance meter.
3 of the 7 16v 10uf were reading less than 7uf and the other four were between 8-9uf. one of them were completely open.

the 100uf's were reading around 80uf

the rest were reading fine, but this was just capacitance not ESR.

Again thanks jetadm123 for some direction.