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mikey32230
Member
Last Activity: 10-29-2021, 09:56 AM
Joined: 06-02-2013
Location: columbus ohio
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    A little while (6 years) later…

    Unfortunately not. I probably still have the disassembled monitor laying around somewhere. I think I ended up desoldering something poorly, probably rendering whatever component useless, became too busy, forgot where I left off and gave up.

    Sorry :/...
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power




    Do you have any advice at this point while budm is in surgery?...
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    So I have searched pretty thoroughly and I cannot find anything close to that IC part number. The link you listed is the closest I have seen.

    Is there anyway to "guess and check" for the VCC pin? Can I just replace it with the IC with the one in the link you provided? or will that not work because it is not the same part number?...
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    So what are my options at this point? Am I stuck because there is no way for me to get a replacement IC? I would love to keep pursuing this repair in anyway possible....
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    Sorry, I wasn't thinking when I said that C702 was a resistor.

    Okay. I desoldered C702 and I still get 2.6-2.8 resistance between those solder pads....
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    Okay, so just so I understand correctly.

    I am desoldering C702 and then... testing its resistance out of circuit?
    or am I powering the switchboard without the resistor in circuit?...
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    Correct, I measured it without power to the switchboard.

    I'm sure that that area of the board gets extremely hot. I'm was not 100% positive the IC is the component that is causing the heat, i thought it could be any of the smaller capacitors, or resistors there that are heating up the entire area including the IC.

    So, I just applied power again and i tried to measure heat with a IR thermometer. I'm not sure how precise it is i could get with which component I was measuring, but based on where...
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power




    1) Okay, so for starters the P/N on the IC is:
    3584A2-7B
    H-N7RP912
    ACA130328

    I have no idea where to find schematics for any parts in this monitor. I have tried to google various part numbers and nothing comes up. Is there a schematics database you know of that may have any of these schematics?

    2) I took off the plastic connector piece (switchboard side) that houses the 6 colored wires. I measured DCV for each pin (red probe on pin, black probe to GND (metal chassis))....
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    Well it's been like that from the beginning, but I must have forgotten that occurred. I had not fully connected the board together For a long time. I narrowed it down to the yellow and brown wires by taking each wire out of the plastic connector on the power button board and plugging them in. In different combinations.

    I know it shouldn't get hot, something is shorted or some resistive component is failing and allowing to much current or voltage to that board...
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    Okay so I tried to Study up basic electronics so I have a slightly better understanding of things. And I also made a few more discoveries that might be more helpful.
    All the fuses appear to be good, they all have continuity.

    The power supply is 19V, when applied to the board approximately 19V run through both ends of fuse F901 when shorted to ground.

    When I power the board and put my probes to both leads of The two capacitors on the bottom left of the board C908 and C907, they both show...
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    I missed fuse F901, but just checked it and it also seems okay. I'm not terribly sure I'm testing them correctly. I'm setting my multimeter to Alarm, and I putting both ends against each solder point. I hear the alarm so that mean current is getting through. I then move the multimeter to OHM (200) and I'm getting readings of about .2

    I believe the center pin (power) is connected to fuse F901, when I do the alarm test with the mutimeter one end to center pin, the other end to each side of the fuse I get the alarm...
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    Last edited by mikey32230; 08-09-2015, 09:43 PM.

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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    Im sorry, can you circle the 1117 parts you see. I'm not seeing those any where....
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    The fuse seems to be good. There only appears to be one fuse. Which is marked K on the lower right hand corner of the board...
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power






    Here are some better pictures possibly? I will try to test any fuses i find.

    How would I find a blown diode / voltage regulator?








    ...
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  • mikey32230
    replied to Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays
    Re: Lenovo li2341twf Monitor - No Power



    Yes, I tested the external power supply, that is not the problem.

    Unfortunately, I have no idea what the fuse is on this board. It does not have any fuses that I am familiar with.

    I dont know what a mosfet is, or where it is on this board.. from what the pictures look like on google. It looks like there are a few mosfets on this board.

    Can you help me find the fuse? and if we find it how can it test it? do i need desolder it first?


    ...
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    Last edited by mikey32230; 08-07-2015, 02:10 PM.

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  • mikey32230
    started a topic Lenovo li2341twf Monitor - No Power
    in Troubleshooting Computer Displays

    Lenovo li2341twf Monitor - No Power

    [U][I]TLDR:[/I][/U] Brand new monitor turned on for a few seconds, wont power on anymore. Motherboard has open unused spots for capacitors... (I don't know what that means). Where should I start / Advice on what to do?

    [U][B]Longer verison:[/B][/U]
    Hello, so I bought a Lenovo li2341twf touch screen monitor about a year ago. Upon opening and first installation, it powered on for only a few seconds and then turned back off. We ordered a replacement, but lenovo never wanted the original monitor back.. so now I have this broken one laying around and I would love to be able to    ...
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  • mikey32230
    replied to New Members - please post your introductions here
    in Announcements & Related News
    Re: New Members - please post your introductions here

    Hello, new guy here
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