Re: Microsoft Surface Pro 5 1796 - No Power
Great general advice, I'm still learning and I've learnt soo much about S0-5 states, power rails, logic etc.
I reckon a decent microscope, bench supply and thermal camera will go a long way in diagnosing shorts...
j64x86
Member
Last Activity: 12-28-2022, 04:41 AM
Joined: 12-16-2022
Location: Johannesburg
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Re: Microsoft Surface Pro 5 1796 - No Power
I took a chance and injected onto VSYS rail and this FET (CSD87334Q3D) heated up, after removal short to ground on VSYS is resolved.
Now VSYS powers the VCORE rail... not sure if the PCH is toast as a result of the failed FET or if it somehow was protected.
VCORE is open, probably because VSYS is awol...Leave a comment:
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Re: Microsoft Surface Pro 5 1796 - No Power
That did cross my mind... oh well it was fun investigating.
When I have more time I will see if I can figure out what shorted pch (besides the CPU)
Thanks for all the help, this forum has solid members!...Leave a comment:
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Re: Microsoft Surface Pro 5 1796 - No Power
Re-testing a bunch of things..
If I measure VSYS on R6319 I get 0.737 V is this a little low?...Leave a comment:
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Re: Microsoft Surface Pro 5 1796 - No Power
I tested this +1VSB to ground and it's 0 ohms...
The caps connected to this fuse U4703 are also shorting to ground, not sure if this is the behavior of the fuse or not (pn AP2553FDC).. U4703 seems to be related to the display port so might be OK to ignore,
I know the the 3.3v rail does have power as I get 3.3V from the SAM, not sure where it's shorting
In other news... I noticed a 2.2uH inductor gets hot....Leave a comment:
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Re: Microsoft Surface Pro 5 1796 - No Power
Interesting observation, when pressing the power button the smaller portion of the CPU instantly heats up for a moment....
Not sure what this means but it's a new data point.
...Leave a comment:
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Re: Microsoft Surface Pro 5 1796 - No Power
Good luck with the plumbing!
Had a go at testing voltage on the various component. Couldn't perform step 6 as the group of components is not present on my board, the other point is under the processor. Step 7&8 are both 0 volts, Step 7 has a # so assuming it should have positive voltage.
Now I'm not sure if the answer to the riddle is in Step 6?
Step 1: 3.299V
Step 2 3.3V
Step 3. 3.291 V
Step 4: 8.8v
Step 5: Skip
Step 6: PCH_DPWROK / Declare deep power...Leave a comment:
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Re: Microsoft Surface Pro 5 1796 - No Power
It's my first time attempting board level repair on something as advanced as this.
Good news, step 24 is reading 0 Volts, so I have the opportunity to troubleshoot Steps 1-23
...Leave a comment:
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Re: Microsoft Surface Pro 5 1796 - No Power
Thank you so much for the power rail info.
on IC U6302
pin #28 REGN = 5.98 V
pin #22 VSYS = 8.8 VLeave a comment:
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Re: Microsoft Surface Pro 5 1796 - No Power
Unfortunately I don't have schematics, really wish I did, couldn't find them without some sort of paywall.
I measured the voltage with the 15v DC connected with and without the battery, it appears that the battery does receive some voltage.
...Leave a comment:
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Microsoft Surface Pro 5 1796 - No Power
Hey There,
Trying to troubleshoot a SP 5 1796 (M1007506-015), most of the caps around the CPU area are shorted.
When tracing from the DC in the first shorts I could find is near the USB & DP connectors.
Tested with diode mode, red to ground.
Two bad caps, marked in red on the attached picture, I currently don't have a bench PSU to attempt power injection, any best guesses as to which of the two could be the culprit?
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Re: New Members - please post your introductions here
Hi there,
Mostly an electronics noob, I understand the basics and have repaired some things following the odd YouTube or guide, I think the most ambitious was a eGPU bypass on an old MBP.
Here to learn and help where I can.Leave a comment:
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