emachines eView 15L - Blinking power light

[jayoung]

I have an emachines eView 15L with a blinking power LED.

The power to the monitor comes from an external brick. The monitor has a main board, separate inverter, and a pcb that takes two ribbons from the main board and converts the video signal into a laptop lcd screen type connector and plugs into the panel. Through troubleshooting, I have discovered that disconnecting the connector to the panel allows the monitor to function normally but without a picture. The power button works, the backlights work, and the monitor reads a signal from the computer and shuts off the backlights and changes the power LED to amber when the signal is removed. When the video cable is plugged in, the backlights stay off and the power LED just blinks.

I am leaning toward a defective panel, but would like your opinions. I am not going to put any money into this monitor as it's value is minimal even in working order.

Thanks!

[alexanna]

Re: emachines eView 15L - Blinking power light

I have an emachines eView 15L with a blinking power LED.

The power to the monitor comes from an external brick. The monitor has a main board, separate inverter, and a pcb that takes two ribbons from the main board and converts the video signal into a laptop lcd screen type connector and plugs into the panel. Through troubleshooting, I have discovered that disconnecting the connector to the panel allows the monitor to function normally but without a picture. The power button works, the backlights work, and the monitor reads a signal from the computer and shuts off the backlights and changes the power LED to amber when the signal is removed. When the video cable is plugged in, the backlights stay off and the power LED just blinks.

I am leaning toward a defective panel, but would like your opinions. I am not going to put any money into this monitor as it's value is minimal even in working order.

Thanks!

I would want to make sure the power supply is good first.
Dose the monitor have a sticker on the back stating the voltage and amperage requirements?
And what voltage and amperage are stated on the sticker of the power supply?

[jayoung]

Re: emachines eView 15L - Blinking power light

I would want to make sure the power supply is good first.
Dose the monitor have a sticker on the back stating the voltage and amperage requirements?
And what voltage and amperage are stated on the sticker of the power supply?

Monitor states DC 12V 3A
Power Supply states 12V 3A 36W MAX

[Rtech]

Re: emachines eView 15L - Blinking power light

alexanna has a good point, in that I had something similar a few weeks ago,and although the meter across the power supply says 12v, the current dropped off markedly when a load was placed on it...a good test is to put a car 12v.21w standard bulb across the the Power supply and ensure the lamp is fully lit.

[jayoung]

Re: emachines eView 15L - Blinking power light

I checked the function of the monitor using a spare 12v 4A power brick that I have with a functioning monitor. The symptoms remain the same.

[momaka]

Re: emachines eView 15L - Blinking power light

There could be an overload on the t-con board (the board that attaches to the LCD panel).

Do you have a multimeter? If so, post some pictures of the t-con board if you can. The area around a surface-mount inductor is of most interest. It's usually near the connector that goes to the video/logic board.

[jayoung]

Re: emachines eView 15L - Blinking power light

Yes, I have a DMM. Attached are the pictures as requested. There are several inductors in the same quadrant as the connectors (L1 and L6 exist, L2, L3, L4, and L5 are labeled, but are not present on the board) Both L1 and L6 read 1.7 ohms.

Thanks

[momaka]

Re: emachines eView 15L - Blinking power light

What you have above is the video/logic board. The t-con is the one is usually hidden under a metal cover on top of the screen and is permanently attached to the LCD panel with thin ribbon cables.

[jayoung]

Re: emachines eView 15L - Blinking power light

Sorry about that, I seen "connector that goes to the video/logic" and went for pictures of the logic board. Here are the ones you were looking for. There are actually two boards that connect to the lcd panel that are connected themselves with a ribbon cable. I tried it without the second t-con board connected, but with the same results.

[momaka]

Re: emachines eView 15L - Blinking power light

Sorry for the late reply.

Looks like you have a reversed t-con board (the components are on the back rather than on the front of the board). The 3rd picture almost shows what I need. If you can take 2 more pics (of the big t-con board) - one overall with the side that has all of the components and another picture of the area around the two round inductors L9 and L10. That should cover everything of importance.

In the 3rd picture you posted, there's a fuse (F1) with "40" marks on top. Check it with your multimeter. Use lowest resistance scale and measure the resistance across the fuse - it should show 2 Ohms or less (depending on how good your multimeter is at low readings) or basically a short-circuit. If you get a "0L" or a "1" on the left side of your DMM, then the fuse is open (bad).

If the fuse is good (shows 2 Ohms or less), check resistance on the input 5v rail to ground. Use 200 Ohms scale. The input 5v rail is connected to F1. That means, put the black DMM probe on any ground point on the t-con (such as the exposed copper areas around the screw holes) and red DMM probe on one side of F1 (it doesn't matter which one if the fuse is good).
Do you get more than 100 Ohms resistance?
- If yes, then there likely isn't a problem on the 5v rail.
- If no, then what resistance do you get?

By the way, just a word of caution: be careful when flipping the t-con board. Those thin flex cables that hold the t-con to the LCD panel are not always glued/soldered very well to the t-con. Try to avoid bending them too much or too many times.

[jayoung]

Re: emachines eView 15L - Blinking power light

Sorry for the late reply.

Looks like you have a reversed t-con board (the components are on the back rather than on the front of the board). The 3rd picture almost shows what I need. If you can take 2 more pics (of the big t-con board) - one overall with the side that has all of the components and another picture of the area around the two round inductors L9 and L10. That should cover everything of importance.

Pictures are attached

In the 3rd picture you posted, there's a fuse (F1) with "40" marks on top. Check it with your multimeter. Use lowest resistance scale and measure the resistance across the fuse - it should show 2 Ohms or less (depending on how good your multimeter is at low readings) or basically a short-circuit. If you get a "0L" or a "1" on the left side of your DMM, then the fuse is open (bad).

Fuse is good (0.4 ohms same as touching the two probes together)

If the fuse is good (shows 2 Ohms or less), check resistance on the input 5v rail to ground. Use 200 Ohms scale. The input 5v rail is connected to F1. That means, put the black DMM probe on any ground point on the t-con (such as the exposed copper areas around the screw holes) and red DMM probe on one side of F1 (it doesn't matter which one if the fuse is good).
Do you get more than 100 Ohms resistance?
- If yes, then there likely isn't a problem on the 5v rail.
- If no, then what resistance do you get?

On the 200 ohm setting, I get OL. On the 2000 ohm scale, I get a reading of 814 ohms.

[momaka]

Re: emachines eView 15L - Blinking power light

Pictures are attached

Perfect. Excellent quality.

On the 200 ohm setting, I get OL. On the 2000 ohm scale, I get a reading of 814 ohms.

Good. Looks like the 5v rail is fine then.
----

There's only a few more other things to check, now that you provided the pictures.

Using the second picture you posted above as a reference, measure the resistance across the following (use 200 Ohm scale only):
- ceramic capacitors (rectangular, beige components) C90 or C91 (doesn't matter which one you pick, since they are connected in parallel)
- ceramic capacitors C92 or C93 (again, it doesn't matter which one you pick).
- ceramic capacitors C603, C75, C78, C602, C76, C601, C80, C79, C81, C82, and C46.
---- if you get OL or over 100 Ohms for any of these, they are likely fine.
---- for the ones you get less than 100 Ohms, let me know what readings you get.

Using the first picture you posted above as a reference, measure the resistance across the following (use 200 Ohm scale only):
ceramic capacitor C41. Like for the other capacitors you measured above, see if you get anything lower than 100 Ohms - if not, then C41 should be good.

I hope this doesn't sound like a lot of work. Should only really take about 10-15 minutes at the most to check these.

[jayoung]

Re: emachines eView 15L - Blinking power light

There's only a few more other things to check, now that you provided the pictures.

Using the second picture you posted above as a reference, measure the resistance across the following (use 200 Ohm scale only):
- ceramic capacitors (rectangular, beige components) C90 or C91 (doesn't matter which one you pick, since they are connected in parallel)
- ceramic capacitors C92 or C93 (again, it doesn't matter which one you pick).
- ceramic capacitors C603, C75, C78, C602, C76, C601, C80, C79, C81, C82, and C46.
---- if you get OL or over 100 Ohms for any of these, they are likely fine.
---- for the ones you get less than 100 Ohms, let me know what readings you get.

Using the first picture you posted above as a reference, measure the resistance across the following (use 200 Ohm scale only):
ceramic capacitor C41. Like for the other capacitors you measured above, see if you get anything lower than 100 Ohms - if not, then C41 should be good.

I hope this doesn't sound like a lot of work. Should only really take about 10-15 minutes at the most to check these.

C90 - 890 ohms
C91 - 890 ohms
C92 - 890 ohms
C93 - 890 ohms

C603 - OL
C75 - OL
C78 - OL
C602 - OL
C76 - 1048 ohms
C601 - OL
C80 - 715 ohms
C79 - 1058 ohms
C81 - 552 ohms
C82 - OL
C46 - 891 ohms

C41 - 913 ohms

[momaka]

Re: emachines eView 15L - Blinking power light

C90 - 890 ohms
C91 - 890 ohms
C92 - 890 ohms
C93 - 890 ohms

C603 - OL
C75 - OL
C78 - OL
C602 - OL
C76 - 1048 ohms
C601 - OL
C80 - 715 ohms
C79 - 1058 ohms
C81 - 552 ohms
C82 - OL
C46 - 891 ohms

C41 - 913 ohms

Pretty healthy readings, or at least everything in the power supply section of the t-con seems to be in order.

Not sure what else to suggest. Perhaps the t-con is working right but maybe there's a problem in the video/logic card?
If you feel like playing with it a bit more, just check the rest of the ceramic capacitors on the t-con board (as they are usually the component that fails the most) for short-circuit. I doubt you'd find anything wrong, though.

Other than that, I also see 2 voltage regulators on the video/logic board. I'm almost positive they should be working (otherwise the buttons on the monitor likely won't function at all, even with the t-con detached), but check them anyways. For these, measure the voltage on each pin with respect to ground.
The one on the right in the picture I included should be a 3.3v regulator, so you should see 3.3v on one of the pins. The other smaller one, I'm not sure since I can't see the part numbers on it.
Let me know what you get.

[jayoung]

Re: emachines eView 15L - Blinking power light

As an update:

I completely took apart the monitor and hooked everything up so I could check voltages at the regulators along with various other components.

I determined that with the wider ribbon cable disconnected, the monitor would function normally and with a grainy image on the screen. During the connecting / disconnecting and unplugging / plugging of the various ribbons and cards, I was able to get the monitor to work. I had it work and then quit working several times before I finally got the monitor to work constantly as it is currently. I think it may have been an issue with the connection to the t-con board. I rubbed the contacts before putting it together this last time, but I'm not sure if that is what got it back to working.

Thanks very much for all of the help and advice, I hope the monitor continues to work. I will test it for a bit before I'm convinced that it will continue to work.

[jayoung]

Re: emachines eView 15L - Blinking power light

I guess you can say wishful thinking......I tried the monitor again and same thing, flashing power LED.

I have discovered through trial and error that the monitor will work with no issues if I allow it to "warm up." If I disconnect the t-con board from the video/logic board and allow the monitor to run for a minute or two (ccfl's lit, just a white screen), then connect the t-con board, it will function normally until I turn it off and it "cools down." It is, however, not the inverter causing the issue since I have a spare universal inverter board that I tried with the same results (flashing power LED). This makes me lean toward capacitors, but not for sure. With 16 capacitors on the video/logic board, I don't think it would be worth the time and money to replace them to verify this is the issue.

[momaka]

Re: emachines eView 15L - Blinking power light

Could it also be the external power adaptor? I've seen flaky external adapters do that - sometimes they start, other times they can't.
If this monitor uses 12v, just hook it up to a computer power supply and see if you can get it to do the same problem.

[jayoung]

Re: emachines eView 15L - Blinking power light

I had tried that earlier with a separate 12v 4a brick that I had here from a different monitor. No change in the function. I actually called it quits on this monitor and scrapped it out for parts (ccfls, heavy metal base, etc.). Thanks again for all of the help, I'm sure I will be back for more with other monitors that I have accumulated here lately.