Re: Dell 2405FPW blown transformer?
Anyone?
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Re: Dell 2405FPW blown transformer?
OK just some updates. I just ran an ohm test on the 7 bigger capacitors (including the 450v), all of them are dead (although there's no signs of physical damage). The needle on my multimeter went to the right, stayed, and never returned to infinity. So maybe the transformer is OK?Leave a comment:
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Re: Dell 2405FPW blown transformer?
Yes! Thank you for correcting me. Forgive me for my ignorance.:pJust to nitpick when you say "current" you actually mean voltage.
It's a very important distinction to make
https://en.wikipedia.org/wiki/Voltage
https://en.wikipedia.org/wiki/Electric_currentLeave a comment:
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Re: Dell 2405FPW blown transformer?
Hello budm. Thanks for helping me again! The reading of the 450v capacitor is 160 volt. I've attached a picture in case I'm wrong. Initially I test it under the scale of 500v on the multimeter. But since the reading is low, I switched the scale to 250v.
Also I tried testing f702 fuse again. The voltage reading is about 7v. Let me do it again tonight to confirm on this.
As far as the big fuse next to the power connector, I tested it again. The needle on the multimeter barely moved on the lowest scale.
Leave a comment:
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Re: Dell 2405FPW blown transformer?
Just to nitpick when you say "current" you actually mean voltage.
It's a very important distinction to make
https://en.wikipedia.org/wiki/Voltage
https://en.wikipedia.org/wiki/Electric_currentLeave a comment:
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Re: Dell 2405FPW blown transformer?
What DCV do you get between the two legs of that large black 450VDC main filter cap?Leave a comment:
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Dell 2405FPW blown transformer?
Hi everyone. I've searched the forum thoroughly about this problem but couldn't find anything similar to my Dell's symptom.
I've repaired this monitor before by replacing two 5v slow blown fuse (F701 and F702) and modified the bad MOSFET on the logic board (under the direction of an electrical engineering professor). I've enjoyed my repair for two years and now it's dead. When power is on there's no response at all, no front LED light, no image.
I'm not an electrical engineer so I can only do a couple of test on the power board. I've attached a picture for you to review. Basically all the fuses have been tested and they're all normal (zero resistance, normal continuity with the multimeter buzz sound). However, when power on, the big fuse next to the power input has no current reading at all, so are the rest of the components. I've not tested the transformer since I don't know how to test the legs. But I'm suspecting that it's a blown transformer?
The only two places that have 120v reading are the power connector and the small resistor behind it. Any help would be much appreciated! Thank you all.
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My 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... -
I have a Dell Latitude 5511 laptop, and lately, a faint but clearly audible electrical (crackling) noise comes from the motherboard, similar to the random clicking coming from a mechanical hdd's heads moving inside it.
The laptop shows no signs of malfunction, and clearly this is electrical not mechanical, so my suspicion goes to a dodgy component in the power rails (a capacitor or a coil?). I fear this could develop into a serious damage.
Any advise on how to narrow it down?
The schematic is available here:
Dell Latitude 5510 5511 - Precision 3551 FDV50 FDV51 LA-J282P... -
First of all, I'd like to mention that I'm a novice when it comes to laptop repair, although I do have some experience with soldering.
One day, my laptop experienced a severe stutter, and after rebooting, it failed to boot into Windows. I decided to disassemble it and found that the PL900 component was blown. Later, I came across a post (https://www.badcaps.net/forum/troubl...error%E2%80%99) with the same problem, where...08-30-2024, 06:13 AM -
Hi,
Could someone help trying to unlock this BIOS, seems that Dell have changed the layout of new Dell Pro 8FC8 bioses from checking HXD - 4000 bits do not need changing, only 2000. However after FF the section starting from '01000' upto 2000 bits and then soldering the chip back it seems that the microchip on the motherboard is recovering the bios back to original settings after first boot. Has anyone found a way to crack this extra layer of security Dell have implemented? Seems both HP and Dell have upped bios security to match Lenovo by implementing extra measures on a separate... -
I would like to share my experience about charging issues with Dell power supplies with the tech community. I am working on a Dell Inspiron 5590, Mainboard 18778-1 with charging problems. The device can be switched on and works so far, only the message appears at startup:
Alert! The AC power adapter wattage and Type cannot be determined. The battery may not change. The System will adjust the performace to match the power available.
The power supply unit is not recognized in the Bios and the charging process is set to "idle". I use original Dell battery, type...
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