Gateway 900G frustration

[Solder Boy]

Re: Gateway 900G frustration

I guess the lesson is you need to be suspicious of ALL electrolytics regardless of how small and insignificant they seem to be.

Yup I will agree with that! Some of the computer motherboards I have fixed is because I decided to check out the tiny little guys for the heck of it, only to be surprised with a ESR reading of 8 or higher.

[capamatic]

Re: Gateway 900G frustration

Recaped the FPD1975W with Panny FC`s and monitor/backlight working perfectly....but...
I have a resolution problem. At one point 1024x768 was fine but now at any setting I get a high pitched whinning and garbled image. I presume the video board is struggling somehow to display at the correct vertical and horizontal frequency.
Googling this monitor shows it has both VGA and DVI, but not mine !...VGA only, strange.
That being the case. I wonder if any of you chaps could confirm the Part No. of the video board.
Thanks.

[EGuevarae]

Re: Gateway 900G frustration

Recaped the FPD1975W with Panny FC`s and monitor/backlight working perfectly....but...
I have a resolution problem. At one point 1024x768 was fine but now at any setting I get a high pitched whinning and garbled image. I presume the video board is struggling somehow to display at the correct vertical and horizontal frequency.
Googling this monitor shows it has both VGA and DVI, but not mine !...VGA only, strange.
That being the case. I wonder if any of you chaps could confirm the Part No. of the video board.
Thanks.

I repaired one without the DVI input. It was tested and it is being used at native resolution, as my card detected. Look up native res/freq. and test it that way.

[capamatic]

Re: Gateway 900G frustration

Good to hear there is a non-DVI version.
Tried at the native res 1440 x 900 at all available freq`s, still bad.
Disconnected the VGA and now the `Gateway` splash screen/`no video input` is garbled too !, initially it was perfect.
Maybe the voltage supply to the Video Board is out of spec. ?

[PlainBill]

Re: Gateway 900G frustration

Good to hear there is a non-DVI version.
Tried at the native res 1440 x 900 at all available freq`s, still bad.
Disconnected the VGA and now the `Gateway` splash screen/`no video input` is garbled too !, initially it was perfect.
Maybe the voltage supply to the Video Board is out of spec. ?

Many video boards have on-board regulators (and their companion caps). Odds are one or more of those caps are bad. It sounds painfully like a problem I had with a VP211b.

PlainBill

[EGuevarae]

Re: Gateway 900G frustration

Good to hear there is a non-DVI version.
Tried at the native res 1440 x 900 at all available freq`s, still bad.
Disconnected the VGA and now the `Gateway` splash screen/`no video input` is garbled too !, initially it was perfect.
Maybe the voltage supply to the Video Board is out of spec. ?

Check voltage out to the VBoard. Then, post a pic (good size/res) of the board to see what 5v->3/3.3v regulators are found and/or check those. It may be a Voltage problem as you said.

[capamatic]

Re: Gateway 900G frustration

Thanks for the input,
Sounds like it would be easier to source a replacement Video Board.
Anyone have a spare?

[capamatic]

Re: Gateway 900G frustration

Didn`t have to look far for the cause of the res. problem


Looks like the recap put paid to the Vreg, assisted by a failing cap.



Burned Vreg.


Marked as A1SB then 51 rotated, doesn`t reveal much. Probably a manufacturers No. and impossible to trace, let alone find a replacement.

So if anyone has a VBoard (200-100-GJ912W) or source for one, I`d appreciate a pointer.

[mr_circuit]

Where can i get the transformer for the inverter circuit?

Hello all, I have this same monitor that i got gave to me. I have found the problem with mine, it is one of the final transformers in the inverter circuit. The secondary side is open. I don't have the schematics or the data on the transformer though. Does anybody on this board know the specs or where i can order a replacement transformer?


I am familar with digi key. I order from them all the time. I have already replaced all the caps on the power supply since one of them was starting to get a bulge on top. I have a solid and steady 5V and 12 Volts out of the supply while hooked to the controller board. Both my back lights are good, I can plug one in on the good side and it will light, then plug the other on the good side of the inverter board and it lights. When i run a conutity test on the transformers, the one that works reads where i would expect a transformer to read, but on the side that won't light my back lights i read an open circuit on the secondary side so i know this is the problem. When i first turn on the moniter it comes on for a few seconds then the backlights turn off, not the power. If i switch it off and back on the same thing happens. I would appreciate any infomation on the transformer so i can get this monitor working again. Thanks all.

[Wizard]

Re: Gateway 900G frustration

That's 5V switch to turn on or off 5V supply to the LCD, usually NPN with very low R-on and logic level input.

Replace it with uprated substitute. That tiny transistor is not rated for that demand.

Second, check the resistance between ground and 5V at LCD to make sure there is no short on 5V input high uF ceramic capacitors on the LCD circuit board. If there one, carefully look for cracked or discolored SMD capacitors otherwise unsolder one by one till short is gone. Usually fuse is first thing 5V comes through but there are other designs that had caps come first then a fuse then more caps.

Cheers, Wizard

[PlainBill]

Re: Where can i get the transformer for the inverter circuit?

Hello all, I have this same monitor that i got gave to me. I have found the problem with mine, it is one of the final transformers in the inverter circuit. The secondary side is open. I don't have the schematics or the data on the transformer though. Does anybody on this board know the specs or where i can order a replacement transformer?


I am familar with digi key. I order from them all the time. I have already replaced all the caps on the power supply since one of them was starting to get a bulge on top. I have a solid and steady 5V and 12 Volts out of the supply while hooked to the controller board. Both my back lights are good, I can plug one in on the good side and it will light, then plug the other on the good side of the inverter board and it lights. When i run a conutity test on the transformers, the one that works reads where i would expect a transformer to read, but on the side that won't light my back lights i read an open circuit on the secondary side so i know this is the problem. When i first turn on the moniter it comes on for a few seconds then the backlights turn off, not the power. If i switch it off and back on the same thing happens. I would appreciate any infomation on the transformer so i can get this monitor working again. Thanks all.

Good job of troubleshooting. I see three possible approaches.

1. See if you can find a part number on the transformer. It might be on the bottom side of the transformer, so you will have to remove the transformer from the pc board. If you can find a part number, Google it.

2. Examine the windings carefully. The point where the winding wraps around the terminal is a weak point and the most likely point for the wire to break. If so, you may be able to fix it.

3. Check on eBay for broken monitors of this series. This thread identifies a number of names under which the monitor was sold.

PlainBill

[mr_circuit]

Update for my monitor

hey guys thanks for your help, I looked up the part numbers that was on the side of the transformer and the only ones that were being sold new that i could find you had to buy in lots of 1000, and i just didn't need that many. So I did an ebay search and did find one guy that had four of them used. I shot him an offer since i thought his price was a little on the hide side for used. He accepted my offer of $10.00 plus shipping. It arrived today in the mail and thought i would let you all know that i am typing this message with the fixed monitor. I hope some of the other people in this thread has had luck getting thiers fixed also but i thought i would give all of you an update and thank you one more time for your help.

cost to fix
aprox. $9.00 for capacitors
$11.50 for used transformer shipped to my door

[JustMe3]

Re: Gateway 900G frustration

Hi everyone involved in this post. I learned a lot and was able to repair a 700G in 10 minutes. I simply replaced the well indicated and circled 47uF cap with a 100uF 35volt cap and it works. I had checked the 5volts previous to the replacement of the cap (despite having no clicking, blue light or any other signs of life), just to see what was going on and it was bouncing, . This post was so impressive that as you can see I joined the group....Thanks for the help.

[runderwo]

Re: Gateway 900G frustration

I saw a post where someone had mentioned getting the backlight connections messed up. It is easy to do because the connectors aren't keyed. The correct wire order from the top down is white, pink, black, grey, on both sets. Note that unexpectedly the black and grey wires will connect to a white and pink harness.

[sceva]

Re: Gateway 900G frustration

I just got a call from someone who can get a pallet of the Gateway 900G, but they ALL have scratched screens. I have done some searching, but can't find a source to even get pricing for replacement lcd panels. Anyone have a suggestion? Thanks.

[Tadehi]

Re: Gateway 900G frustration

Hello, I apologize for the bumping of this thread, but I have a quick question about the 900G Gateway monitor.

I disassembled the monitor after having the ticking noise and initially replaced the capacitor that was 47uf 25V with another of the exact same specs. The monitor would turn on, but only for a second and it would have black lines on the sides. I then replaced all of the capacitors on the board 4x220uf 25V and 5x470uf 25V and in the process discovered a blown capacitor. After replacing all the capacitors, the screen would turn on and the lines went away, but it would only stay on for a second, then go dark. Does anyone have any suggestions that I could try? I am going out of my mind with this monitor.

Thank you!

[PlainBill]

Re: Gateway 900G frustration

Hello, I apologize for the bumping of this thread, but I have a quick question about the 900G Gateway monitor.

I disassembled the monitor after having the ticking noise and initially replaced the capacitor that was 47uf 25V with another of the exact same specs. The monitor would turn on, but only for a second and it would have black lines on the sides. I then replaced all of the capacitors on the board 4x220uf 25V and 5x470uf 25V and in the process discovered a blown capacitor. After replacing all the capacitors, the screen would turn on and the lines went away, but it would only stay on for a second, then go dark. Does anyone have any suggestions that I could try? I am going out of my mind with this monitor.

Thank you!

"Two seconds to black". What capacitors did you use as replacements?

PlainBill

[Tadehi]

Re: Gateway 900G frustration

Manufacture wise, I'm not to sure. The 470uf 25V are brown in color with a white stripe indicating the negative side and says KZE. The 220uf 25V are gold in color with a black stripe indicating the negative side and have a logo that looks like an E and a backwards D. I used these same capacitors (same company) in another monitor that went bad and they work just fine.

[PlainBill]

Re: Gateway 900G frustration

Manufacture wise, I'm not to sure. The 470uf 25V are brown in color with a white stripe indicating the negative side and says KZE. The 220uf 25V are gold in color with a black stripe indicating the negative side and have a logo that looks like an E and a backwards D. I used these same capacitors (same company) in another monitor that went bad and they work just fine.

Bad caps are a known cause of teh 'Two seconds to black' problem. The KZE are probably United Chemicons, and should be good (provided they are not counterfeit). As far as the others, who knows? I suggest posting pictures of both. Maybe someone will identify them.

PlainBill

[EGuevarae]

Re: Gateway 900G frustration

Bad caps are a known cause of teh 'Two seconds to black' problem. The KZE are probably United Chemicons, and should be good (provided they are not counterfeit). As far as the others, who knows? I suggest posting pictures of both. Maybe someone will identify them.

PlainBill

I agree. We have to rule out a cap problem before moving to other components/parts, or the lamps themselves