Newbee mac mini 2010 820-2577-A - Repair Questions

RE: Newbee mac mini 2010 820-2577-A

Guest 9259 — Tue, 02 Aug 2022 18:12:50 +0000

Hi all,

I odered a power supply to do current injection.. But i have a question because the last time i tried to turn on the mac mini it's power supply broke ( with smoke and melted wires..).

So my question is if i power the motherboard with my lab power supply (max 0.8 volt and 1Amp ?) is there a risk that i'll burn out the power supply ?

Many thanks for any answer !

RE: Newbee mac mini 2010 820-2577-A

Guest 9259 — Sun, 31 Jul 2022 22:04:15 +0000

hi all,
the mosfet is out off the board but i still have a shortcircuit.
Nothing look burned visualy and without a power supply, a thermal camera and the schematic.. It's hard to figure out what the matter with this board.
If someone think to something..
thanks.

RE: Newbee mac mini 2010 820-2577-A

Guest 9259 — Sat, 30 Jul 2022 17:25:52 +0000

Hi all.
i come back with somes news..
I've found a mosfet that have drain connected to source ( beep on continuity mode).
if i've well understand it should not so i try to remove it to see if my shortcircuit it's still here but i can't remove it.. i've tried with my solder iron and also with the heat station but without success..
i'm afraid to make more mistakes..

what i'm doing wrong ?

thanks !

RE: Newbee mac mini 2010 820-2577-A

Guest 9259 — Sun, 24 Jul 2022 18:09:55 +0000

Hi other question..
Can i test the mother board supplying it with AA battery with 0.85 v ( i chose low voltage cause i read that if there is a short near from the cpu it could burn it.. thanks !

RE: Newbee mac mini 2010 820-2577-A

Guest 9259 — Sun, 24 Jul 2022 17:33:02 +0000

Hi all i tried to mesure the resistor between the ground and the cap's pads ( the one that i removeed ) on one side i've got 9 ohm and on the other side i've got 0,1 ohm is it normal ? ( sorry if there are basics questions ..).
I alos mesure the resistor between the ground and the big coil pads and there is no sign of short cut on them as i obtain some values and not 0 or near to 0.
i don't own a power supply to test so what can i test with my multimeter ?
thanks.

RE: Newbee mac mini 2010 820-2577-A

Guest 9259 — Fri, 22 Jul 2022 08:50:51 +0000

And the dead power supply…

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RE: Newbee mac mini 2010 820-2577-A

Guest 9259 — Fri, 22 Jul 2022 08:47:07 +0000

Here a picture of my hiroshima ^^

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Newbee mac mini 2010 820-2577-A

Guest 9259 — Fri, 22 Jul 2022 07:22:25 +0000

Hello all.
First of all many thanks for this place and the yt channel !
Looking at yours videos make me want to try to repair computers myself and so i'm here !

My first experience does not start very well ^^.
i've got a 2010 mac mini ( 820-2577-A) with ram issues.
the first time i tried to switch on it's worked , but only once tafter that it's start to beep on boot every time with or without ram sticks in ^^( only one beep every 5 sec meaning that the ram it's not found).
i can't find the schematics for this board but when looking on the inernet i find this page : https://logi.wiki/index.php/A1347_2010-2012_common_issues

so i tried to test the capacitors show on the logiwiki page and with my litle knowlege there seems to be all good. So i continue to test others caps ( those who look like the previous one) and find one that give me 0 ohms.. Yesterday i planed to replace the presume faulty cap and replace it by a new one.
i have to heated a lot to remove this one ^^ but i done it replace it and restart the mac mini without nothing just to see if it was still beeping and no more beep !( i was so proud ! only for few secs..) So i switched it off plug in a monitor and started again and bam or bang as you want ^^ the mac died .. The power suplly cable melted ...
I does have add a short on the motherboard.. and killed the power supply..
One cap near the one i removed beep in continuity mode but give a value so i don't thing it's in short circuit..
If some one had some track to follow i'll appreciate..
i'll post a picture to show my first hiroshima as it's said on vidéos ^^.
thanks for reading me and thanks again for the job donne ( videos , forum etc ).
Ps : sorry for my english i come from france) .