That sounds exactly like my problem, and no - I still haven't resolved it
It's sitting in my room waiting to be fixed still :3...
HexInverter
CD40106
Last Activity: 04-07-2011, 05:12 PM
Joined: 08-25-2010
Location: Manitoba, Canada
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
That sounds exactly like my problem, and no - I still haven't resolved it
It's sitting in my room waiting to be fixed still :3... -
Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Alright!
Sorry for the age long reply...life kinda got in the way...it probably will again, but I must see to it that this puzzle is solved eventually!
I got some time today to revisit the ring test, as per the updated instructions. I had to isolate the signal with a capacitor as said, and BLAMO! - I got ringing to display! Unfortunately the transformer exhibits a very nice (and identical) ring on both secondaries...so no easy fix! Shucks!
So, any idea of...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Okay - both of the waveforms appear to be the same. It doesn't look anything like the ring in your image. Is my oscilloscope broken? I don't know why it doesn't display vertical lines.
Also, the square wave generator I speak of is just a basic CMOS oscillator - not an extremely accurate function generator or anything, so the square wave has a very slight corner on one edge of the waveform. Is this going to render the test useless?
That would be a bummer if it was the oscilloscope...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Are we building ourselves a home made ring tester? Haha...I have no idea what one is, but this is cool!
Off to try that, I'll report back in a bit!
...
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Okay! Hopefully this means something
I can only assume that this many zero voltages readings is a bad thing 
I took my DMM and measured all of the points. Just like the oscilloscope, there's only ever a reading when the transformers buzz. I was pretty sure they are AC voltages, as someone mentioned near the beginning of the thread that everything's AC after the SMT FET, but figured I'd measure both AC and DC in case I was wrong.
Here are the results (I...Last edited by HexInverter; 08-28-2010, 01:01 PM.Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Okay, well I just got back from trying these tests out...
I tested the scope just to make sure I can get a waveform on it with a simple square wave oscillator. No problemo, so I think it works. Onto the tests...
When testing over the transformer, I can't get a stable waveform - though there is one when the buzzing I described earlier happens.
This is what happens:
- I turn the monitor/power bar on, the blue power LED comes on
- A moment later,...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Okay, I've got the whole thing rigged up and ready to go - just one more thing before I proceed with the tests, if you don't mind.
When you say the oscilloscope ground goes to the inverters corner ground plane, do you mean the ground clip on the probe, or the oscilloscope's ground connector on the bottom right in the picture I attached? I've always used the probe's ground for low current/voltage circuits, without hooking up the ground on the oscilloscope, but I have no idea which one to...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Great, makes sense now - thanks! Sorry for all my silly questions by the way...I'm one of those people that can't stand being unsure about something...especially when it's line voltage I'm dealin' with!
Yeah...I'm real bad with those close ups. I don't have a tripod for my camera, and the image stabilization on it is AWFUL you can't take a clear shot unless it's on a tripod or your arms are rested up against something - hence why my shots are always up close (resting...
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
I should say, I am unsure of the safety of removing the PCB's from what I assume is the earth grounded chassis holding them there - is this safe? Do I even need the logic board plugged in to run these tests?
I can't see any way of manipulating that super short cable without losing something (LCD connectivity or the metal casing the boards are screwed into)Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Lol! Oops
Forgot to attach 'em!
Here goes:...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Okay Bill, so while getting all set up for this, I've run across an issue (maybe?) and just wanted to get some clarification before I plug anything into line voltage - As you can see form these shots, the inverter backplate design isn't going to let me test it in its chassis with everything hooked up the way it's supposed to be. The limiting factor appears to be the short, wider ribbon cable that goes from the logic board to the LCD.
So, for these tests - I think I either need to not...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
First, thanks for the great write up! That really sheds some light on what I'm doing here with the inverter.
It all makes sense except for one thing I'd like to clarify on before I go ahead and start on this - when you say to place the probe just below the inverter transformer (In Test #1), you mean to say that I am not going to actually touch any traces on the PCB or component leads, but rather pick up a signal through the PCB from the transformer? That's what it seems...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Okay...back from the vets! One less animal in pain so that's good My girlfriend sent me a text however, and it seems I had forgotten that I'm seeing her tonight! Hmm...I guess I was having too much fun with this
Anyways, I reworked the joints on the transformers, as well as swapped the 22uF out for 2x 10uF's in parallel - the problem still exists, so I guess it definitely is scoping time. It will have to wait until tomorrow unfortunately though
Thanks for all the...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Okay, I had just enough time to snap some pics before racing out the door!
Here we go!...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Apologies in advance for my ignorance - how do I multi quote on this forum?
Crap! Somehow I totally missed this post until going back and reading now! I will probe around to try and find this. Thanks for the ideas!
Also, I tried resoldering the FET, but was being cautious about heat...unfortunately even with my Hakko at 700F it was taking forever for the blob to get anywhere near melting, and the package was getting HOT, so I stopped. I don't think I...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Nope, no ring tester
Yup, that's how the SMD tab was. I will check and resolder that joint. I'm going to have to be really careful not to toast the FET when removing solder though!
My camera battery just died...argh. I always forget it plugged in on data transfer mode to my PC, and the stupid thing doesn't have an auto off function (nor does the battery charge from USB)!
I do however have an old analog oscilloscope. I haven't used it much...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Oops, I forgot to add - there is most definitely a buzzing sound coming from the inverter when it's trying to power the CCFL's. The buzzing stops when the CCFL's go out.Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
I followed your advice closely - also once turning the power off I clicked the power button on the monitor a few times to help discharge the caps.
I used insulated pliers to switch the connectors around.
I had to come up with a way of seeing the bottom of the screen without disturbing the setup...I knew that pile of CD roms I have would come in handy some day! haha
Unfortunately, the monitor still does it, having tried replacing...Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Yup! I just wasn't sure if it was safe to do it both ways or not. I will give that a shot and let you know how it goes....Leave a comment:
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Re: Acer x193w with Darfon B092-XXX inverter - assistance needed! [lotsa pics!]
Okay, so I am testing my Acer's potentially bad CCFL's with a good inverter board then? Just to clarify - I assumed at first I would be testing my inverter with good CCFL bulbs.
It doesn't sound too hard I always discharge filter caps with a 60w bulb just to be safe.
Okay, so there is a pinout for my header pin connector that goes to the logic board, but it has no 12v on it! I see 3x "5v1" pins, 3x GND pins, one DIM pin, and one ENA pin...nothin'...Leave a comment:
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