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Re: [help] a1708 820-00840 dead
From where is the background noise coming from ? Is it from the speakers of this laptop ?
What is the history of this unit ?
Does the cap-lock key LED turn ON / OFF ?
Is this unit power cycling or will remain to consume the same current after turn on ? -
Re: [help] a1708 820-00840 dead
background noise....is outside...
hystory is increasly "random reboots" in the course of last months. now completely dead
caps doens't turn on
about power cycling...look at this video...
https://vimeo.com/717602413
i can say that if i disconnect the battery and reconnect it, and try to power on, i can feel that cpu become a little bit warm...
If i disconnect battery keep pushing power button and reconnect the battery, fans will go to full speed
macbook comes with an hub usb/hdmi/lan adapter. if i connect this adapter, it seems that mac go in bootloop (display of power metere go on and off)
with my adapter no problem at all
ps i don't know if it is a coincidence, but after i have done check you have ask for, cpu is ultra hot!!Comment
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Re: [help] a1708 820-00840 dead
Disconnect this adapter - most of them are crap designs.macbook comes with an hub usb/hdmi/lan adapter. if i connect this adapter, it seems that mac go in bootloop (display of power metere go on and off)
Try again to see if the unit boots or still boot looping. CPU hot may be a hint that the processor is toast.Comment
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Re: [help] a1708 820-00840 dead
like i said, with my adaptor or without any adaptor , it doesn't bootloop
the video i've posted show how it work with my adapter or without any adapterLast edited by phantomEVO; 06-06-2022, 02:35 PM.Comment
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Re: [help] a1708 820-00840 dead
If fans are running full blast, you have performed a SMC bypass.
https://discussions.apple.com/thread/8050875Comment
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Re: [help] a1708 820-00840 dead
i've discovered something...it is not totally dead.
when i power it on, i have backlight with no image. no CAPS LOCK, but i can click on trackpad. no fan spin. and after some minutes, cpu become hot (i think because fans don't spins)
if i disconnect the battery, reconnect and connect power supply, fan start spinning some minutesLast edited by phantomEVO; 06-06-2022, 04:01 PM.Comment
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Re: [help] a1708 820-00840 dead
solved booting from usb...Comment
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Re: [help] a1708 820-00840 dead
Can you post the resolution?Comment
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Re: [help] a1708 820-00840 dead
yes
i've booted from usb, fixed the ssd via recovery and reinstalled the Operating systemComment
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I am new to mac repair, trying to drive right into some of my dead macs laying around.
I have a a1708/820-00840 board that pulled 20v/.02amps. Had a short to ground on PPBUS_G3H. Removed F7000 to confirm it was PBUS_G3H, which it was. Nothing looked bad so injected 12 volts into F7000 PBUS_G3H pad, which lit up Q7680. Pads P3V3S5_VSW were all short to ground so I removed L7690 which cleared those shorts but I am still short to ground on L7690 on pin 1. I am scared to inject this line with dcps beacuse it has lines to the U0500.
Thanks. -
Hi all,
As the title suggests, how can I be sure that my EC chip is really dead?
I've recently gotten into this hobby of laptop repairs, and have successfully brought back to life a couple with some easy fixes, mostly shorted caps.
Now I'm working on HP Probook 455 G8, that had some "devil" run around on 3V line, burning a bunch of stuff. Luckily I have a dead 455G7 (for spare parts) so I managed to fix it (swapped burned parts) to a point that it will charge (both on barrel jack and usb-c), but it doesn't want to turn on. There is a 3V3 on a keyboard... -
Hi,
I have a strange issue with a macbook pro.It works fine for 1-2h and after that is dead unles i leave it to rest for a long period of time.This could be concludent with a heat related issue...but the only thing heating up is the CPU.I use "hwsensors" for temperatures display and "macs fan control" for turning the fan up to keep the device cooler.I have tried to turn the fan all the way up but to no avail,as the issue persists.
So,when the strange occurs,the screen goes blank and stops responding to any command.I can still see the backlight... -
hello guys,
i need help to repair a edm-033 ps2
history : as always hdmi port and usb ports destroyed after unplugged
after change them, ps5 dead too : 1 beep, no blue light. after inspection 1.8v power was shorted, and because of dead panasonic chip. after remove it : no short anymore
so i changed it
now i have got 5v stby,, 3.3v stby, 3.3v power, 1.8v power and no short on them
but the ps5 is dead again : 1 beep, near 10 seconds with power lines and then off, no blue light ...
i don't see any projection of liquid metal on pcb.
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Hello everyone hope all doing well!
I have this PSU (GPS450-AA delta oem) around for like 4-5 years and I had it recapped early 2020 or 2021 with mostly UCC KY and Nichicon PW's. The bulk was and still is fine, the original Ltec's were bloated and empty. The previous issue was some major coil whine noise and at times random shutdowns when going idle. Today it started tripping the mains breaker and I think I have dead APFC mosfets (20N60C3). Right now upon checking I have the Q1 and Q3 FETs dead so far and I guess those are responsible for the PFC circuit. The only thing I care is If there...
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