Re: A2159 dead, no known damage
After installing the board back into the chassis (incl. connected battery) the input goes from 5V to 20V 0.4A to 20V 1.2A to 20V 2.2A to 20V 0A.
The moment it hits ~40W, U3200 gets very hot.
With thermal paper, i can determine that the upper left side of the chip is where it is hot. This is where all of the connections to PPDCIN_XB_G3H_F are.
Same situation on the second USB port, but I do not know if the second chip gets hot as well, as it is currently on the underside.
What do these chips have in common that...
Fyod
Member
Last Activity: 01-19-2023, 08:37 AM
Joined: 06-26-2020
Location: Prague
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Re: A2159 Macbook Pro 820-01598 stuck on 5V
No shorts on coils, LDO rails are okay.Leave a comment:
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Re: A2159 Macbook Pro 820-01598 stuck on 5V
Anyone made any progress? I seem to have the same problem.
A2159 with small traces of water inside. Would not go to 20V, ultrasonic cleaning lead to the 20V working again, both TB ports are okay.
[B]When on charger, 5V lines are power cycling.[/B]
Input showing 20V, current cycling from about 350mA to 800mA.
PPBUS_G3H 12.36V (slight dip to 12.26V every 3s)
PPDCIN_G3H 20.30V
PP20V_USBC_XA_VBUS 20.30V (depending on which is connected)
PP20V_USBC_XB_VBUS 20.30V ^
PP3V3_G3H_RTC...Last edited by Fyod; 03-18-2022, 01:41 AM.Leave a comment:
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Re: A2159 dead, no known damage
I have noticed that PPBUS_G3H dips from 12.36V to about 12.24V, PP3V3_G3H dips from 3.3V to 2.6V at about the same interval as PP5V_G3S jumps to 5V.
There has got to be a short somewhere when PP5V_G3S is supposed to turn on, just can't find it.Leave a comment:
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Re: A2159 dead, no known damage
I'm still looking around the board for a short (so far unsuccessfully) before I replace the resistors.
Is 3.4Ohm to ground normal for CPU rails?Leave a comment:
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Re: A2159 dead, no known damage
R7672 0.945k
P5VG3S_CSP1 (pin 7) pulsing 5V, pin 8 same
No corrosion, both look ok.
Edit: R7673 is 0.945k as well,Last edited by Fyod; 02-28-2022, 05:43 PM.Leave a comment:
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Re: A2159 dead, no known damage
So I got the laptop. Seller either didn't know or lied, either way there was corrosion from liquid on about 5 spots. Seems like water as there was no gunk or sugar.
On first try, the input (original 96W charger) read 5V, 0.4A.
After a thorough ultrasonic clean and dry, I get 20V and jumping current between 0.04-0.09A. So at least I got PD negotiation back.
I have gone over the board under the microscope and I do not see any obviously damaged/burned parts.
There was only a smoke trail on the thunderbolt connector itself,...Last edited by SMDFlea; 02-28-2022, 05:15 PM.Leave a comment:
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Re: A2159 dead, no known damage
Yes, I have all the tools needed and have done laptop repair in the past.
I have found the BV and schematics for the model as well.
My question is mainly in regards to the CPU, because I know that models like the 12" Retina just suddenly die irreparably.
Guess I'll try.Leave a comment:
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A2159 dead, no known damage
Hi all,
I'm looking at buying and fixing an A2159 for myself.
Seller says his son brought him the laptop saying it just suddenly turned off. Pretty sure they tried charging/booting.
No mention/sign of liquid damage or drop.
Are there any known issues on these models like sudden CPU death?
I know it's just wild guessing, but I would like to have some idea of what to expect before diving in.
Cheers! -
Apple TV3 A1427, A1469 or TV2 A1378
Looking for brd files for any of these Apple TV models.
Cheers! -
Re: A1708 No boot, liquid damaged
BumpLeave a comment:
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Re: A1708 No boot, liquid damaged
Any ideas?Leave a comment:
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Re: A1708 No boot, liquid damaged
So I lifted one side of L7210 and L7220 to isolate the problem. Now the short is only on PPVCCCPU_S0G. SW1/2 are now in the kOhm range and I get 0.42A stable input, fan spin, CPU heats up. No display though.
I injected 0.5V 2A into PPVCCCPU_S0G to see if anything gets hot, but I can't find anything even warm. Checked the CPU of course, not warm either.
Is there anything else I can try?Last edited by Fyod; 04-15-2021, 01:22 PM.Leave a comment:
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Re: A1708 No boot, liquid damaged
Thank you.
So obviously no normal. I'll check the 7220/7210 chips.Leave a comment:
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Re: A1708 No boot, liquid damaged
I read somewhere that low resistance is common on CPU lines.
Are the above values in the norm?Leave a comment:
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A1708 No boot, liquid damaged
How bad is it if I'm getting
[CODE]CPUVR_SW2 0.25Ω
CPUVR_SW1 0.33Ω
PPVCCCPU_S0G_PH1 0.30Ω
PPVCCCPU_S0G_PH2 0.35Ω
PPVCCCPU_S0G 0.30Ω
PPBUS_G3H_CPU 1.1mΩ (stable 13.1V)[/CODE]
to ground?
Could there be a common cause? Blown U7220/7210?How bad is it if I'm gettingCode:How bad is it if I'm getting [CODE]CPUVR_SW2 0.25Ω CPUVR_SW1 0.33Ω PPVCCCPU_S0G_PH1 0.30Ω PPVCCCPU_S0G_PH2 0.35Ω PPVCCCPU_S0G 0.30Ω PPBUS_G3H_CPU 1.1mΩ (stable 13.1V)[/CODE] to ground? Could there be a common cause? Blown U7220/7210?
Last edited by Fyod; 04-09-2021, 03:01 PM. -
Re: Lenovo laptop burned/shorted power rail repair
Sounds like the mosfets are shorting to ground giving you 5x20V in series.
I would remove all mosfets and take measurement, then replace the mosfets and make measurements after every replacement. They have to be gone after such a blast, imo.
You could theoretically find the mosfets' datasheet and check them after removal based on the pinout. It is always more reliable to measure parts off the board.
30K to ground seems reasonable.Leave a comment:
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Re: Lenovo laptop burned/shorted power rail repair
Yes, the vias go straight through.
The problem is that there could be traces in the 4 or so layers between the top and bottom that run close to the vias.
If such traces were affected then repair is almost impossible.Leave a comment:
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Re: Lenovo laptop burned/shorted power rail repair
Also check/replace that diode PD403 and the transistor next to it.Leave a comment:
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Re: Lenovo laptop burned/shorted power rail repair
Geez.
Luckily it's a large ground, so you might get away with digging down into the board to remove any burned material/copper. Keep checking continuity until there's no short.
You'll also likely have to replace the FETs because I doubt the cap caused this, more likely one (and consequently more) of them failed. Remove them until there's reasonable resistance to ground all around that area.Leave a comment:
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