Re: Need help troubleshooting power circuit on Dell Lattitude E7450
You men the inductor removed from the circuit? It measures 0.2 Ohms out of the circuit both ways. It also measured the same in the circuit.
I also tried to remove PU800 but it was not coming off. I did not want to go over 800 deg so I stopped. There's something mounted on the other side under it. A card slot or something....
shaundh
Member
Last Activity: 01-19-2022, 11:31 PM
Joined: 08-27-2016
Location: LILBURN
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Re: Need help troubleshooting power circuit on Dell Lattitude E7450
I removed PL700 from the circuit and it still only measures 0.2 Ohms. There are a couple of capacitors still shorted to ground on both sides though. But shouldn't PL700 have more resistance than 0.2?Leave a comment:
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Re: Need help troubleshooting power circuit on Dell Lattitude E7450
I do see PU800 now. It does not seem to be getting hot. Only thing getting hot is PL701 near Pl700 after some time. Not too comfortable with removing PU800 though. I'm going to keep testing....Leave a comment:
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Re: Need help troubleshooting power circuit on Dell Lattitude E7450
Lost internet here after the storm.
I can't even find PU800 on the board. I'm starting to think the schematic does not match my board. I will try the above again powering for a longer time. But I think I'm going to remove PQ700 which is the AO4435 mosfet....Leave a comment:
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Re: Need help troubleshooting power circuit on Dell Lattitude E7450
I’m at 2v 9amps and I don’t feel anything getting hot when I inject voltage into PL700....Leave a comment:
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Re: Need help troubleshooting power circuit on Dell Lattitude E7450
These are all the square inductors I found on top of the board. Did not find any on the bottom:
• Inductor readings:
○ PL500 = 65.5 Ohms
○ PL700 = 0.2 Ohms
○ PL701 = 4.6 Ohms
○ PL101 = 3.69 Ohms
○ PL102 = (constantly moving, draining from 500k Ohms down and back up again)
○ PL200 = 446 Ohms
○ PL301 = 1.9k Ohms...Leave a comment:
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Re: Need help troubleshooting power circuit on Dell Lattitude E7450
Yes, it is adjustable. I just bought it about a month ago. Hanmatek HM310. I will report these values back later today. Thanx for your help....Leave a comment:
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Re: Need help troubleshooting power circuit on Dell Lattitude E7450
Yes. I have a soldering station and hot air with a 30v power supply. I can solder pretty good but if the components are too small…… Im using a fluke 117 but no microscope or o-scope. I did not see any visual damage to the board or components that were obvious. I'll try to get my hands on a microscope though....Leave a comment:
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Re: Need help troubleshooting power circuit on Dell Lattitude E7450
Here is the schematic...Leave a comment:
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Re: Need help troubleshooting power circuit on Dell Lattitude E7450
Yes, I'm using the original adapter and I found that schematic here but I don't know how to read it....Leave a comment:
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Need help troubleshooting power circuit on Dell Lattitude E7450
I just got a pretty nice Dell Lattitude E7450 laptop from a friend to try and fix. When the charger is plugged into the laptop, the light on the adapter immediately goes out. I disassembled it and took the board out. I put 3v to Vin at charge port and found that mosfet AO4435 was getting hot. That was the only component I found to get hot and there are no signs of damage to this chip or any component . There are also several caps that are grounded on both sides when testing for shorts but I can't tell if this could be by design, due to the bad mosfet, or other condition. Question is, how likely... -
Re: Need help with Toshiba 32AV502R TV. No picture or sound, just lines
Here is what it looks like with programming playing....Leave a comment:
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Re: Need help with Toshiba 32AV502R TV. No picture or sound, just lines
This is what it looks like.
Update: I finally got sound from the TV. I kept switching through the inputs and turning up the volume until I got a noise from the Apple TV menu. I can hear clearly but there is no movement on the screen. There are greenish white vertical lines across the whole screen now. I'm guessing that the panel is bad. It's just strange that I can't seem to agitate the problem by touching the flex cables. So, am I right in assuming the panel is bad?...Last edited by shaundh; 10-27-2016, 06:56 PM.Leave a comment:
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Need help with Toshiba 32AV502R TV. No picture or sound, just lines
I'm having a hard time getting started trouble shooting this TV. When I got it, it would turn on (I get green light and backlight) but I got no picture or any sound. I just got some vertical greenish lines on the left side of the screen. I took the panel apart and touched the flex cables connected and there was no change. I switched inputs and no change or sound. So I guessed it was the main board. So I found a mainboard on ebay, installed it, and the exact same behavior as before. I was sure it was the main board because I got NO respose from volume, input, menu, nothing. But it's still doing... -
Re: hisense 55k610gwn no power no standby
Man! I'm working on this same board. Got the exact TV today. It burned some components though. Not to thread jack, but I will subscribe to this thread.Leave a comment:
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Re: Samsung LN46A500T1FXZA fixed
I too replaced C102 with a SMD 100uF 10V CAP and all is working will on my Samsung LN40A630M1F. I was kinda forced into this repair because I purchased a replacement main board only to find out that it was incompatible. Turns out multiple board have the same model# printed on them, i.e. BN41-00975C. But there are other model#'s printed on the board too. Mine had the following:
- BN41-00975C - printed on main board
- BN40-00125A - on coaxle male connector
- BN97-02474A - on sticker on board
The replacement had these:...Leave a comment:
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