Is this CPU failure?

Hello everyone. I try to fix a console after water drop.

Console is no start up with charging current 0.4amp and I confirmed charging current was 0.040 amps with disconnected battery.

I already confirmed no visual damage on the board.

I found low voltage value points at capacitors which were installed back side of CPU. (see attached picture) I’m sorry to use this figure without permission.

First, I would like to confirm that the value written in this figure is measure by diode mode with red probe to ground and the value mean 0.090V if the value written “90”.

In this case, CPU had shorted damage?

Best regards.

Whats the resistance to ground here?

Thank you for your reply.

I added the values of the resistance to ground.

Minimum value is 13.3ohms. I feel like that if the short circuit is exist, the value getting almost 0 ohms.

As a result, this console does not have a short?

All values of the resistance to ground were measured while M92 IC was removed.

Hmm is this a Mariko/patched board?

Is “Mariko/patched” mean the new generation switch which is the serial “XKJ” series?

The board I repairing is XKJ series.

Yeah, think that’s Mariko.

From memory, I’m pretty sure a resistance of approx 13 ohms is normal on this rail, so don’t think that’s your issue.

I continued trouble shooting and I found this Mariko console was into the auto RCM mode.

I tried to connect PC and Tegra RCMgui showed the RCM OK.

Is there the way to disable the auto RCM mode on mariko console?

AutoRCM is not enabled on this console, it’s not possible to enable this on Mariko consoles, nor will it boot payloads.

The reason it’s being detected in RCM is because the SoC is in some sort of panic state. There is a whole host of things which can cause this, you might want to rule out the EMMC as the issue and see if your able to back up the EMMC and if yes that you can write this backup back to th EMMC without write errors.

I knew that for the first time.

I would like to know how to back up EMMC.

If I can not take a back up EMMC with some error, is EMMC dead?

You can use something like this on PC which will allow you to test read and write functionality, you won’t be able to access the hidden boot0/1 partitions but it will serve your purpose.

Or simpler yet, plug the EMMC module into an unpatched board. Though, make sure you boot straight into Hekate and don’t allow HOS to boot incase you inadvertently burn the update fuse if your unpatched board was on a lower FW version.

Then just do a full backup in Hekate, then write the backup back and if it’s successful and there is no errors then the EMMC is not your problem.


I tried to backup EMMC using hetake, but showed “failed int EMMC” error message.

Is there the way to repair this console?

I have some experienced the hardware repair, but, I have not experience the software repair.

Can I replace EMMC?

If I don’t have a backup EMMC data, Isn’t there the way to repair that?

Unfortunately no, as the EMMC (data) is tied to the SoC.

Not without the Biskeys which unfortunately you won’t have.

What was the original cause of the console failure, was it impact damage or liquid corrosion?

If it was impact damage then it’s possible a reball would fix the EMMC and if it was liquid can you take a photo front and back of the EMMC in question so I can see?

Failing that, there are more advanced ways to try recover the data from the EMMC but tbh it’s not worth the effort :frowning:

The cause of failure is water damage.

However, there is no big corrosion damage on this board.(there is evidence of water only.)

I have one with exactly the same issue, the console can be sent payloads, but won’t init the emmc. I also tried it on a PC with an SD adapter, and it doesn’t show the partitions (usually it does).

I have tried a reflow, but it didnt help. I am thinking of reballing it and putting it on a dead consoles board, is that the best option or are there better / easier ways of extracting the info so I can copy it onto a new emmc?

There are several Vias there which I can see which are gone, check continuity and compare to a known good from one side to another and ensure continuity.

After repairing ensure there is no corrosion below the EMMC less you permanently damage it when applying power, it’s possible it’s already dead.

Failing that, you can reball the EMMC IC and put it on another PCB but you will require reball experience.

Depends what the original fault condition was and what caused it. it’s possible the IC is just dead and cannot be recovered without serious data recovery tools.

You said check continuity and compare means check continuity and compare using each pins of EMMC connector?

Kindof, compare the vias (Vias are the gold plated through connects, compare to a good one to see what I mean) which have erroded away and ensure they have continuity from one side of the board to the otherside, then check and compare continuity and diode/resistance reading in both polarities both from the connector but also the various vias (which don’t go to the connector) and compare to a known good. If all tests well, or after repair everything tests well, flux boil the EMMC IC to try help shift any liquid corrosion below it, don’t reflow it.

These IC’s moreso than others are paricularly sensitive to liquid than others and it really takes very little to kill them, in cases like this when the vias have corroded away you stand very little chance of the IC having survived, I’ve had maybe 1/10 which has lived to tell the tale :slight_smile:

I will study a lot.

What is the flux boil?? same as reflow? or low temperature heating??

Right, your just looking to activate the flux but not bring the solder up to melting temp, depends on your flux but from memory, generally speaking, 180C to 220C is fine to pull any crap out from under the IC, might want to do a few passes,then after the same with alcohol to remove the tired flux.

Just ensure those Vias are good and failing that,you may have to switch the IC over to another PCB but as I said the chances of recovery are low as liquid typically causes the controllers within these IC’s to fail, afer which you left with raw nand recovery which isn’t easy and which I’m currently inviestigating but tbh it’s not worth the time or effort.