Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
Are c805 and C 811 the two caps on the inverter section.
Did you measure the voltage at them yet
I dont think we know yet that the c806 is a problem on your board.
Try easy things first.
I suppose setting it up then heating where c806 is to see if it makes it go off would be a test
Dell E228WFPC goes dim after 10 minutes, not 2 seconds
Collapse
X
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
These are easy to do if u smother the end in solder and quickly heat up both sides then lift using tweezers or push to the side with the soldering iron.
Smd caps can be bought from the usual places. Can't see ur location on your profile so not are where to suggest.Leave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
FYI - I replaced C805 and C811 today (470uf 25v each) and no change. On the off chance that POM_MJ meant C805 instead of C806. I didn't check this thread for updates until AFTER I'd swapped out those caps.
OK, I'm pretty handy with a soldering iron, but WTF?
How am I supposed to change that surface mounted cap?
Metal tweezers and a low temp iron with a pencil tip?
Where can I find said cap?Leave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
That makes sense since it is hooked up as softstart, but with resistor in place (leaky cap), then it is setup as Deadtime control.Leave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
When BAD C806 (in my case) warmed-up, it has leakage current flow through it then cause the voltage at PIN4 goes higher than normal and pulse duty cycle goes wrong, that make lamps current incorrect, then protection scheme shutdown the oscillator, I thought.
edit: IPboard 715G2594-1-4 (HUDSON8) schematic uploaded for reference.Attached FilesLeave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
I look at the SCH, PIN 4 is the Dead time controller pin, per SCH, it is setup as SOFT-START mode since R818 is not used. It is interestin that C806 caused the lamps to go dim, it must have change the ON time of the lamps.Attached FilesLeave a comment:
-
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
Cant see C806 is that a ceramic smd on the back?
What voltages do you get on the two black caps in the inverter side of the PS (one is possibly c805)Leave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
Try to replace C806.
I had the same symptom with the same IPboard.
I used hot-air to locate heat affected component then found C806 conduct when it heat, replaced with 0.1uF/50V 0805 running fine for 2 months.Leave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
I am just trying to find out if the two ballast caps have leakage resistance when you check them with the Ohm meter.Leave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
I did test all the caps on both boards with my ESR meter.Leave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
"I metered the blue caps near the transformers and got similar ohms between the two (secondaries, right?)"
So are you able to read the resistance of these two blue ballast caps?Leave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
Oops! Been looking at too many Dell boards today. Some of them had separate inverter boards.Leave a comment:
-
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
A photo of your inverter board would be helpful.Leave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
Update: I brought a sister monitor home today and swapped in the boards from the known good monitor with my panel. I gave it to my wife to work on all day with her design work.
Result: no problems all day.
OK, that's good, at least that means I've narrowed the issue down to the inverter or logic board(s).
So what now? Start stressing my suspect boards with brightness adjustments, or a hair dryer?Leave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
https://www.badcaps.net/forum/showthread.php?t=19987Leave a comment:
-
Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds
"Before I try any hair dryer tactics, it would probably be a better idea to place my panel on the boards of a known working donor monitor. If the problem migrates, then I know it's a CCFL issue."
Sounds good plan to me likewise if you have the panel off a donor try it on
these boardsLeave a comment:
-
Related Topics
Collapse
-
by BowlineMy question pertains to understanding the control circuity inside a Dell PT434 type battery used in Dell E6400, E6410 and other Dell notebooks?
Does anyone have a circuit diagram for the inside of a Dell PT434 battery and/or a description of how the control lines work to control this battery?
My reason for asking is I have a battery which I cannot get to charge beyond 1% in a Dell E6410 or E6400.
The LED bar graph charge indicator on the battery shows one LED lighted when the info button is pressed.
I have tried multiple different Dell power adapters. My Dell... -
by aaronkatriniHi all,
I have recently picked up this Dell OEM Nvidia GTX 750Ti 2GB Video card. Its an old card I know but still wanted to get it working if possible. The problem is the following:
- Put the card in my testing motherboard and start running Heaven benchmark
- Benchmarks seems to run smoothly up until half way then the motherboard completely shuts off immediately
- Try to start it again and I get a slight move from the PSU fan - a clear short
- A little troubleshooting later I find one shorted Mosfet - Replace them both - short is gone
- Put the... -
by DrFalkenHello everyone!
Motherboard model: FDI55 LA-J081P
Today a customer delivered this laptop completely dead, with the original power supply shorting when plugged into the connector.
I found and replaced a shorted MOSFET (PQZ3).
Now the laptop turns on (fan runs fine but no video signal) and after 5 seconds it turns off.
BIOS has already been updated (both 64MB and 128MB IC)
+3VALW and +5VALW are still present.
+VCCIN = 1.8V stable (measured on PLZ1 at power up)
Abnormal readings:
PLZ1 to GND = 0 Ohm
PLZ2 to GND = 0 Ohm
... -
by Kambi13Hi all need some help, I've got a Dell insprion 15 3542 that turns on works for about 30 seconds or sometimes a minute or two and then turns off and wont turn on again until I remove and replug the power connector
Not heat related, everything is ok regarding to that.
All voltages are present.
Wondering if this as anything to do with one wire circuit, the charger is not original, but it was working fine
Motherboard is Cedar 13269-1 F3XMC Rev A00... -
I've got a Dell Latitude 5580 which came in for no power. It's not exactly a no power issue though. The battery was puffy so I replaced that, but the symptom is that when the power button is depressed, the keyboard backlights will come on for about 10 seconds then go back off. Before depressing power button, I am drawing 112ma and oddly, there is no change in current draw once the button is pressed and the keyboard backlights illuminate.
Any ideas? - Loading...
- No more items.
Leave a comment: