emachines e19t6w inverter powersupply help

[bagginsbill]

hello I am new to the site and I need help with somthing. I am not too good with computer but i do understand some of it. My monitor has a problem with the backlight and I cannot find a site or anything that sells the inverter/powerboard. If you turn the monitor on the backlight will light up for about a second and then go off. all 4 backlights work out of the board I tried them one at a time. they only will come on when the monitor gets turned on . the power harness to the board from the picture board remains the same voltage while its on when the lights are on to off I will have pictures up soon Ive been using a multi meter and I tested the wires so far . on the wire harness it goes 1 vcc5v 2 vcc5v 3 gnd 4 brightness 5 on/off 6 gnd Ive tested all these with the monitor coming on while backlights come on and then go off and it remains ssteady voltage while they are on and off so I figure the problem is on this board I cant see any buldging caps or anything but i will post pictures hoping you guys cann see somthing or have an idea thankyou

[bagginsbill]

Re: emachines e19t6w inverter powersupply help

[bagginsbill]

Re: emachines e19t6w inverter powersupply help

[bagginsbill]

Re: emachines e19t6w inverter powersupply help

ill try to get better pictures those are pretty bad

[bagginsbill]

Re: emachines e19t6w inverter powersupply help

i found a picture of the same board here some people are having other problems with gateways

[bagginsbill]

Re: emachines e19t6w inverter powersupply help

the monitor does come on during start up of the computer or if you press power buttons the LCD itself stays on but the backlight goes out after a second or 2 any idea anyone?

[PlainBill]

Re: emachines e19t6w inverter powersupply help

the monitor does come on during start up of the computer or if you press power buttons the LCD itself stays on but the backlight goes out after a second or 2 any idea anyone?

2 seconds to black symptom. Search on it and post better pictures of the bottom side of your power supply / inverter AFTER reading this.

PlainBill

[bagginsbill]

Re: emachines e19t6w inverter powersupply help

that good picture is not a picture of my board but the same type of board. here are pi ctures of my board I cant see any swelling in the caps or anything but on the bottom of the board there is a smear of black/blue on one of the little things that say 421? i circled it in red I have been reading a thread on this monitors with bad caps which ones should i replace to fix? the big 470su'scon one?

[PlainBill]

Re: emachines e19t6w inverter powersupply help

that good picture is not a picture of my board but the same type of board. here are pi ctures of my board I cant see any swelling in the caps or anything but on the bottom of the board there is a smear of black/blue on one of the little things that say 421? i circled it in red I have been reading a thread on this monitors with bad caps which ones should i replace to fix? the big 470su'scon one?

Bad caps CAN cause this problem. Su'scon is not one of the brands of caps that inspire confidence. The large 100 uF, 405 volt cap is not likely to be the problem. It WOULD be a good idea to replace all the other caps with good quality low esr caps. I prefer Panasonic FM or FC series, there are a number of recommended caps listed in the 'Which caps should I buy' thread in the FAQ.

But first, let's eliminate some other possible causes. I've circled the outputs of the inverter transformers in red. The pins I've circled in blue MAY be the other end of the secondaries. Check the resistance from each of the red pins to each of the blue pins. When several blue pins are soldered to the same land it is not necessary to check all of them. If you DO show connectivity, report the resistance for each secondary. If all red pins read open to all blue pins, then check the resistance between the red pins on each transformer and report those numbers.

If the transformers check out I'm going to need a much better picture of the area of the card to the left of the yellow line.

PlainBill

[bagginsbill]

Re: emachines e19t6w inverter powersupply help

heres the best picture i could get without getting batterys from the store. Can you tell me how to test it with the multimeter? and i will get the results does the board need to be on and powered?

[PlainBill]

Re: emachines e19t6w inverter powersupply help

heres the best picture i could get without getting batterys from the store. Can you tell me how to test it with the multimeter? and i will get the results does the board need to be on and powered?

To measure resistance the power must be off. Make sure the monitor is unplugged.

Turn the meter on and set it to the 20K Ohm resistance scale.

Test 1: Hold one probe (either one) on one of the points I've circled in red. Touch the other red point with the other probe. Do you get a reading on the meter? If not, try the other transformer. If you do not get a reading on either transformer, post a picture of your meter.

Test 2: If you got a reading in Test 1, while holding the first probe on the red circle, touch the second probe to each pin I have circled in blue. Do you get a reading on any of them? If you do, note which pin it was.

Test 3: Move the first probe to the other red pin and check each of the blue pins. If you do get a reading, note which pin it was. If you don't get a reading there either, I will assume there is a single, untapped secondary.

Test 4: Now set the meter to the 2K ohms range. If you got readings from the red pins to blue pins in tests 2 or 3, repeat them, noting the readings. They should be very close to each other. I would the reading to be in the order of 1K ohm. If you did not get any readings in tests 2 or 3, measure the resistance from one red pin to the other, I would expect that reading to be higher. (The idea is to get the most accurate readings possible).

Now repeat the tests for the other transformer. Compare the readings from test 4. If all of them are within 1% of one another all transformers are probably good.

PlainBill

[bagginsbill]

Re: emachines e19t6w inverter powersupply help

with my craftsmen 82456 meter only has ohms scale not different ohms but the decimal place moves and puts a letter after the number. I am testing this with the board unplugged and on a desk from red to red top two and bottom two i get .690k on the top two and then .651k on between the bottom two then i moved on in sets top two reds to top blues and bottom red to bottom blues i get 2.950m across the board or close for both sets and here is the only big picture i could find of the multimeter since my camera is dead now

[PlainBill]

Re: emachines e19t6w inverter powersupply help

with my craftsmen 82456 meter only has ohms scale not different ohms but the decimal place moves and puts a letter after the number. I am testing this with the board unplugged and on a desk from red to red top two and bottom two i get .690k on the top two and then .651k on between the bottom two then i moved on in sets top two reds to top blues and bottom red to bottom blues i get 2.950m across the board or close for both sets and here is the only big picture i could find of the multimeter since my camera is dead now

You have one of those new-fangled autoranging DMMs. In my day I was happy to have a VOM.

One problem with a thread that has large pictures is the text stretches across the entire page and beyond, which makes reading difficult, especially in the 'stream of consciousness posts like the above.

Stripping away the excess verbiage, you get 690 ohms on the secondary of one transformer and 651 ohms on the other. That is about a 5% difference, and almost certainly indicates shorted turns on the transformer that reads 651 ohms.

PlainBill

[smason]

Re: emachines e19t6w inverter powersupply help

You have one of those new-fangled autoranging DMMs. In my day I was happy to have a VOM.

Luxury! We used to have to lick our fingers, place them on the B+ and measure how high out hair stood up,
after calibrating (allowing for number of days of hair growth) to a known voltage (120v)
VOM indeed....

[PlainBill]

Re: emachines e19t6w inverter powersupply help

Luxury! We used to have to lick our fingers, place them on the B+ and measure how high out hair stood up,
after calibrating (allowing for number of days of hair growth) to a known voltage (120v)
VOM indeed....

You had hair?? Some people had all the luxuries.

PlainBill

[bagginsbill]

Re: emachines e19t6w inverter powersupply help

lol, but back to the transformer that transformer is bad you say? why wouldnt the other two backlights from the other transformer light normally? I also tried to edit off the big picture but it wouldnt let me edit that post for some reason if a mod could do it id appreciate it

[bagginsbill]

Re: emachines e19t6w inverter powersupply help

also i tested red to red dots again this just now and its lower readings 611 on the top 2 and 619 between the bottom 2 from red to blue its still the 2.9*** range across the board for both sets of blues

[PlainBill]

Re: emachines e19t6w inverter powersupply help

also i tested red to red dots again this just now and its lower readings 611 on the top 2 and 619 between the bottom 2 from red to blue its still the 2.9*** range across the board for both sets of blues

My wife teaches 'Language Arts' in Middle School. I complained about the difficulty of reading your posts. She looked at one and was not sympathetic. "Looks like it was written by an Eighth Grader" was her comment.

An inverters protection circuits usually monitor the output voltage and current through the CCFLs. If a transformer has shorted turns in the secondary this reduces the output voltage, but the CCFL may still light, just not as bright.

I've marked up the picture again.

What is the resistance from A to B?

What is the resistance from C to D?

What is the resistance from A to 1; from A to 2; from A to 3; from A to 4; from A to 5; from A to 6?

PlainBill

[bagginsbill]

Re: emachines e19t6w inverter powersupply help

The resistance from A to B is .613k ohms. The resistance from C to D is .618k ohms.
The resistance in the following A1 through A6 is as follows ; A1 2.934M , A2 2.942M , A3 2.945M ,
A4 2.951M , A5 2.955M , A6 2.961M. They all did climb slowly and when I went back to test
A1 it had risen to the same as A6 at 2.96*M

[PlainBill]

Re: emachines e19t6w inverter powersupply help

The resistance from A to B is .613k ohms. The resistance from C to D is .618k ohms.
The resistance in the following A1 through A6 is as follows ; A1 2.934M , A2 2.942M , A3 2.945M ,
A4 2.951M , A5 2.955M , A6 2.961M. They all did climb slowly and when I went back to test
A1 it had risen to the same as A6 at 2.96*M

613 vs 618 ohms is very close, less than 1%. So it's probably NOT the transformer.

It's your decision. There are other tests that can be done, but it could be a week before I get around to marking up the picture. In any case, replacing the caps would be a good idea.

PlainBill