iMac 21'5 4k 2017

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • jasonr2000
    Advance Tech
    • Nov 2013
    • 209
    • UK

    #1

    iMac 21'5 4k 2017

    hi guys I have the above iMac

    and it appears to be dead

    I have replaced the PSU with a known working one and same result no lights on the logic board or anything.

    it just wouldn't turn on one day.

    ive done some basic testing on the logic board with a vault meter and I find some caps are shorted both sides ???

    is this normal ?

    any advice on where I can look id be grateful

    cheers

    Jason
    Samsung UE46D6530
    Samsung BD-F7500
    Samsung HT-ES6200

Related Topics

Collapse

  • tommy97
    iMac Pro 2017 A1862 SSD Upgrade & Recovery mode
    by tommy97
    Hi,

    we've got iMac Pro 2017 which having a problem with SSD, iMac come with 2 SSD's 1TB, it was having a problem with the SSD so we get the replacement, installed in and iMac is stuck in recovery mode, tried to restore it & revive, nothing worked - error 4010. After installing old drives now we're having the same problem that the device is in recovery mode. Previously after swap of the SSD iMac worked on the old SSD however after attempt of revive on the new SSD machine stuck in recovery mode, I can go to DFU but the same result with error 4010.

    Any ideas what might've...
    04-20-2024, 04:48 AM
  • mat2k
    iMac 2017 PSU - shorted PFC mosfet
    by mat2k
    I am trying to fix an iMac 2017 PSU, initially came with a blown fuse and shorted PFC MOSFET (6R199P). After visual inspection and some measurements I replaced the FET with a P20NM60 and tested with 100w series lamp, and it lasted 1 second before going into dead short. The PFC controller chip (NCP1605BG) and its passives appear fine (passives measure OK), but I do not know if there is a simple way of testing the NCP1605 as I wouldn't like to blind-replace it.
    There was some slight blackening of the solder on the PFC controller passives so I reflowed them all with some flux. I am waiting...
    03-13-2025, 11:31 AM
  • mon2
    In search of T2 rom dump for iMAC 2017 A1862
    by mon2
    Hello all. Have an imac that is not able to create PP1v8_S5 and there are no shorts on the rail. Unable to DFU due to USB not working. Suspecting corruption of the T2 firmware.

    Welcome all suggestions. Thanks.
    08-13-2024, 08:13 PM
  • Crystaleyes
    Can an iMac chime if the logic board is bad?
    by Crystaleyes
    Hi all.

    A friend has a 2011 iMac which chimes (and apparently plays music) but was told by a technician that the logic board needs replacing.

    The screen stays black, but music apparently plays when the keyboard 'play' button is selected.
    A bit beyond my experience...??!!??

    I was under the impression that bad logic boards don't give the Apple chime.

    Anyway, they are bringing it over tomorrow where I'll check the diagnostic LED's to get a better idea. Seems more like a PSU, GPU or inverter problem to me.

    A bad...
    04-02-2022, 04:28 PM
  • iZakre
    HP Pavilion 15 bc400ns - Complete Black Screen - Only video on live usb
    by iZakre
    Hello everybody!

    To put you in context I recently replaced the battery from my HP Pavilion 15 bc400ns with a used one, everything was going good. The same day, I decided to update the BIOS, everything went good. The thing occurred after I let the battery drain iddling on Windows 11 for the second time to calibrate it that the screen did not turn on again, the computer was on but the screen did not turn, like it would not wake from hibernation. I decided to restart the computer but got no video.

    The thing is that I had installed TeamViewer and could log into the computer...
    02-19-2023, 02:27 PM
  • Loading...
  • No more items.
Working...