Gateway FPD1760 LCD Monitor

[leaver]

At first, the monitor did not come on at all so I Replaced 10 caps on the power supply board (all but 100mf 450v). Now the blue power light comes on but the LCD screen is all white. I read on some of the various badcap threads that this may be due to a blown fuse on the t-cont board. Where is this board located? The shielded metal box on the back of the LCD panel just has two boards - the power supply and a logic board that the vga cable from the PC plugs into. Do I have to take the back off of the LCD panel to get to the t-con board?

[retiredcaps]

Re: Gateway FPD1760 LCD Monitor

It is the long board at the top of the lcd monitor. Follow the LVDS cable from the main board "north" and you will find it.

[leaver]

Re: Gateway FPD1760 LCD Monitor

Thanks for responding "retiredcaps." I found the long board and it looks like there are two possible fuses labeled F1 and F2. They are near one another and are both labeled with the number 110 with the letter P over each number. They both appear to be good (0 ohms) with my multimeter. I will try to get a picture tomorrow but I am not sure my camera batteries are charged or I can get the resolution you are asking for.

[lexwalker]

Re: Gateway FPD1760 LCD Monitor

Thanks for responding "retiredcaps." I found the long board and it looks like there are two possible fuses labeled F1 and F2. They are near one another and are both labeled with the number 110 with the letter P over each number. They both appear to be good (0 ohms) with my multimeter. I will try to get a picture tomorrow but I am not sure my camera batteries are charged or I can get the resolution you are asking for.

Try checking the supply voltage to the Tcon board. Check whether its too low, no voltage at all, or noisy (if you have a scope).

[leaver]

Re: Gateway FPD1760 LCD Monitor

lexwalker: Do you know which pins on the T-con connector (at the LVDS connector) have the supply voltages?

[budm]

Re: Gateway FPD1760 LCD Monitor

Measure the DC voltage right at the both ends of the fuses, black probe to chassis.

[leaver]

Re: Gateway FPD1760 LCD Monitor

Budm: Are the F1 and F2 that I mentioned earlier the fuses on the T-con board?

[jetadm123]

Re: Gateway FPD1760 LCD Monitor

Budm: Are the F1 and F2 that I mentioned earlier the fuses on the T-con board?

Yes, they supply the voltages for the T-con.

[lexwalker]

Re: Gateway FPD1760 LCD Monitor

lexwalker: Do you know which pins on the T-con connector (at the LVDS connector) have the supply voltages?

As mentioned earlier by others here, you can check them at the fuses. You can also trace them to the connectors and the main I.C on the Tcon. Usually if the fuses check out fine then check the supply voltage. Another place to check is the 3.3V regulator on the Dscaler board which supplies the power to the Tcon board. Lack of and/or loss of this voltage can lead to white screens.

[leaver]

Re: Gateway FPD1760 LCD Monitor

I checked the voltage on both sides of F1 and F2 on the T-con board as follows:
1) When power was turned on, the blue light comes on.
2) After a 5 second delay, the voltage on both sides of F1 and F2 reads 4.98 volts.
3) The IC1 regulator next to F2 has 3.3 volts on center pin.
3) The LCD display is all white (fairly bright).
4) After about 5 seconds, the display turns off and the power light goes to amber.
5) Voltages at F1 and F2 go to zero.

The CRT on my 5o year Eico 460 O'scope is so dim that I don't think I will be able to measure the ripple on the supply voltages. I will have to borrow another scope from a friend to check if that is needed. Thanks for the help so far.....

[leaver]

Re: Gateway FPD1760 LCD Monitor

I am attaching pictures of the 3 boards in my Gateway FPD1760 LCD monitor.

[jetadm123]

Re: Gateway FPD1760 LCD Monitor

There's also another 3-pin voltage regulator above the first one you checked. It's marked 1084-18PE. You should read 1.8v at the output.

[lexwalker]

Re: Gateway FPD1760 LCD Monitor

I checked the voltage on both sides of F1 and F2 on the T-con board as follows:
1) When power was turned on, the blue light comes on.
2) After a 5 second delay, the voltage on both sides of F1 and F2 reads 4.98 volts.
3) The IC1 regulator next to F2 has 3.3 volts on center pin.
3) The LCD display is all white (fairly bright).
4) After about 5 seconds, the display turns off and the power light goes to amber.
5) Voltages at F1 and F2 go to zero.

The CRT on my 5o year Eico 460 O'scope is so dim that I don't think I will be able to measure the ripple on the supply voltages. I will have to borrow another scope from a friend to check if that is needed. Thanks for the help so far.....

4.98 Volts? The Tcon board could be using 5V supply instead of 3.3V. Can you tell us the panel brand and model? You should be able to see that on sticker label on the panel itself...

[leaver]

Re: Gateway FPD1760 LCD Monitor

The large sticker on the back of the LCD panel has the following on it:
BOEhydis and a number to the right which is HT17E13-100 and it says it is made in Korea.

[budm]

Re: Gateway FPD1760 LCD Monitor

5 volt for T-CON is correct. The T-CON I deal with uses 5V for panel less than 24inch, most big panel uses 12v. There should have other voltage regulators (1.8v, 3.3v , etc.)/switching power supply for the Gamma control, the controller of the processor, etc.

[leaver]

Re: Gateway FPD1760 LCD Monitor

Jetadm123: The 1084-18PE regulator is on the T-Con board and the output is 1.79 volts.

[lexwalker]

Re: Gateway FPD1760 LCD Monitor

The large sticker on the back of the LCD panel has the following on it:
BOEhydis and a number to the right which is HT17E13-100 and it says it is made in Korea.

This panel uses +5V supply (see attachment). Usually there's a FET transistor that switches it on or off (controlled by the main Dscaler I.C). If there's voltage to the Tcon but still no display (all white blank screen) then there's a possibility that the Tcon's dead. Of course try checking other possibilities first before declaring that, such as the voltage regulators on the Dscaler board. You can also force the Tcon to switch on by shorting the FET transistor that controls it. With the Tcon on all the time and with no video signals present from the VGA and/or DVI port, there should be some self test patterns (in some Tcons, they behave like that).

[budm]

Re: Gateway FPD1760 LCD Monitor

You can see the switching power supply done by the round black surface mounted inductor in pic #5 post 11. Can you see any test point pads with voltage labeling next to them?

[leaver]

Re: Gateway FPD1760 LCD Monitor

I am including a better focused picture of the center section of my T-CON board so you can see the area around the surface mounted inductor you referred to. I don't see the test point pads with voltage labels but maybe you can since you know what to look for. Also, do you know if there are any service manuals available for this monitor on the Internet? Or, if it was made by Samsung for Gateway, is there an equivalent Samsung model that may have a schematic on the Internet? Thanks.

[lexwalker]

Re: Gateway FPD1760 LCD Monitor

I am including a better focused picture of the center section of my T-CON board so you can see the area around the surface mounted inductor you referred to. I don't see the test point pads with voltage labels but maybe you can since you know what to look for. Also, do you know if there are any service manuals available for this monitor on the Internet? Or, if it was made by Samsung for Gateway, is there an equivalent Samsung model that may have a schematic on the Internet? Thanks.

Looks like an obselete TI Tcon I.C there. And from the picture, there seems to be a stepdown DC-to-DC converter or regulator there as well, possibly for Tcon I.C? Some Tcon I.Cs from TI have internal pattern generator for panel self test. Don't have the datasheet for the I.C in your image, but do check any voltage going to that I.C (possibly around 1.8V to 3.3V)...