Shorted Cap Near m92 and MAX77620

Seems normal without emmc but CPU should not go hot in that case. Warm but def not hot

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No worries, that seems more like normal

It’s not your fault. I’ve seen quite a few people refering to this rail as the ā€œCPU railā€ and in turn that cap below M92 which resides on said rail as the ā€œCPU capā€ … not really sure where that all started but what you’ll find as you become more experienced is the repair community (particularly the youtube repair crowd) is it’s a vaccum and it only takes one person to get something wrong or to do something stupid and others who don’t know any better will copy and the cycle repeats… for example, one idiot starts using a rotary tool with a diamond bur to remove solder mask <0.1mm thick (the same bur I’d use to drill holes in masonary, tiles or glass) and then every man and his dog starts doing the same thing :roll_eyes: :smiley:

That all being said, the SoC is also connected to this rail but so is pretty much everything else - it’s produced by the PMIC which is why after you reballed it seemingly cleared the short here.

Yeah could be. It’s entirely possible now though, given that this IC produces some all important rails for the SoC and if things were touching which ought not to have that the SoC may have died, or the PMIC might be bad in and of itself.

Don’t be, this board looks like it’s been through the wars anyway… plus it’s alway nice to have a parts board :+1:

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These are my next actions.

imma re-ball the ram first and then the soc for fun and see what happens, also i already made the purchase for the SOC stencil so its to late now LOL, its good practice either way.

As for parts, Do you think the PMIC chips are still good in this case? I’ve read they don’t really go bad in other posts here.
im thinking when i reball i should inject voltage again at the coil and see if it still shorts as i take the ram and soc off

Just a word of warning if you don’t know already, you want to get the 80x80 or 90x90 stencil in combination with the jig and preformed balls for the SoC. A direct heat stencil and solder paste won’t work (or rather your setting yourself up for failure with this type) I’d start with Ram first and go from there.

Details regarding the jig here

don’t know if I covered the stencil to use along with it for the SoC in that topic but it will be there or somewhere else on the forum somewhere :slight_smile:

Under normal circumstances the PMIC is quite resiliant but in cases like this where somebody prior has purposely messed with it it’s hard to say, all depends on what was going on below it after he/she messed with it…

No, search the forum regarding checking your primary rails (resistance relative to ground) which I’ve covered a bunch here to get an idea of if anything is still shorted out and to get a map of the current state of things - if everything checks out then you atleast know what is good if/when you start reballing Ram, PMIC and later SoC (in the event your install goes bad or you damage the chip/s during reflow) all of which you’ll be able to test prior to ever connecteing power (far safer) and/or you find the short and in doing so you’ll be able to determine if pulling the IC’s we’ve discussed resolves the issue (whihc we can narrow down if you do find something) - what you were doing earlier was connecting power up to your SYS rail (which is basically the source voltage for most things and pretty well every other rail derives from it in some way shape or form), subsequent short on 1V8PDR (possibly dragging SYS down as a result) trouble is/was your putting other things in the line of fire doing this.

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