Oh. Thanks a lot. I will take a look at it. I am just fighting with an another switch. Until now I could repair ca 15 out of 18 and now this is the 3rd in a row where I cannot repair them 
I would need some success already 
Somebody already tried to repair it. It is charging perfectly (15V 400mA). P13USB was exploded on the back. I replaced it, the filters are ok but still nothing on the screen. I tried to check AutoRCM mode and it shows that it is RCM OK even without the jig (in TegraGUI). Tried to inject Hekate. It uploads succesfully but still nothing on the screenā¦ I do not really know how to continueā¦
What code does TegraRCMGui give after injecting?
No RCM device detected
RCM Device detected
Invoking TegraRcmSmash.exe with args : āE:\Programok\TegraRcmGUI_v2.6_portable\favorites\hekate_ctcaer_5.0.0.binā
TegraRcmSmash (32bit) 1.2.1-3 by rajkosto
Opened USB device path \?\usb#vid_0955&pid_7321#6&3af0f9ce&0&7#{aa0dbd45-3117-f331-5c49-76bf65225042}
RCM Device with id XXXXXXXXXXXXXXXXXXXXXXX initialized successfully!
Uploading payload (mezzo size: 92, user size: 126207, total size: 192423, total padded size: 192512)ā¦
Smashing the stack!
Smashed the stack with a 0x0000 byte SETUP request!
Payload successfully injected
This is what it drops.
I just checked that maybe this is a patched switchā¦XAJ4005. This is in the mixed range.
If yes, did I kill it now?
Unit is patched unfortunately.
P13 wonāt have any negative consequences unless itā's bad and dragging a rail down, so donāt think thatās your issue
Check all your primary rails first (resistance to ground)
Just putting this out there, but Iāve had a few in the past that had mismatched EMMC modulesā¦ banged my head against a wall only to discover later with a modchipā¦ not saying thatās your issue as it could be a number of things but worth bearing in mind
No you didnāt kill it donāt worry. Itās the 0x0000 that lets us know itās patched
Before I replaced P13 the cap above it was on short. As soon as I replaced the short was gone. I was quite optimistic that it will work but notā¦
I can see that work has been done on the BQ and the M92 chip also beforeā¦ I was surprised why they did not replaced P13 USB.
Tomorrow I will start measuring the main rails.
Thanks a lot again. I owe you already with something because you always help me a lotā¦ 
Iām always suspicious in situations such as this, itās quite likely if they failed to spot the short around P13 that they didnāt properly install the M9 IC and in particular the BQ IC, both of which but more eyes on the BQ IC could prevent the system from booting. Iād start by replacing both of thiese chips with fresh ones just to rule them out before checking the primary rails
Might also be worth taking a closer look at the USB port too
I will do this. Altough I just today received a batch of new M92 IC and I think they are fake. I already tried To replace M92 on this one and in one direction it was not even showing up on my usb meter and on the other side it was showing 5V but no current drawā¦ I put back the one it was on it and immediately charging with 15V 400mA.
I am really pissed.
At least I have new good BQ chip so I will start with that.
Iām in two minds as to whether there are truly fakes being madeā¦ While itās true there are a lot of fakes for other mainstream ICās coming out of china itās typically only ever done on ICās of a particular age and/or ones that are hard to aquire as theyāre out of production. I think itās far more likely these are salvaged parts which have been ārecycledā Iāve seen this many, many times.
I seem to recall you can get these ICās from the legit distibutors, maybe stock up if you wind up getting the cleaning solution from farnell.
btw the fact that the board was showing up as an RCM device even without the jig might imply issues with the EMMC module or the rails which it utilizes, 1V8PDR and 3V3PDR.
They look pretty much new without any solder residue on the pads. I will maybe try a second oneā¦
If I remeber correcrly I already checked some of the distributor and I could not find them that time. Tough I will recheck them once again.
This does not sound promizingā¦ The 1,8 and the 3,3V lines are present because I measured those. Although I will today recheck all the rails also in resistance mode.
Sorry my bad, your quite right, I must of been thinking of another IC.
If the others from your batch donāt work, maybe pull the M9 IC of the donor you put in the ultrasonic earlier?
Yes, I have some donor boards. Now I reordered them from the same store like before. They all worked though 25% more expensiveā¦
I have replaced both M92 and BQ. Still the same. No shorts on any of the power rails. On the front non of the MAX ICs are turning on. On the back I have 3,3V, 1V, 1,1V, 1,4V, 1,8V. There is no 5 V, and no backlight.
I cannot find anything comparing to a good board. It is charging with 15V 730mA. Are there any way to check if the EMMC is corrupted?
Voltage measurments donāt really mean muchā¦ whats your resistance to ground on your primary rails, in particular 1V8PDR and 3V3PDR?
Yeah but itās complicated, there aere ways which weāll delve into afterwards
730mA is a strange measurment btw and implies some signs of lifeā¦ have you verified LCD connector?
1,8V PDR above the MAX iC 2,6kOhm. 3,3V rail et ENXX IC few hundred kOhm and jumping up and down.
The 1V rail on the left of the MAX IC is 36Ohm on a known good board 53Ohm
Maybe it is just my USB meter. I used to see ~700mA on 15V with it If I use a 5V charger that is either 450mA or 1,4A with the same meter.
ney good, try disconnecting the EMMC module and taking that reading again, you shuld be seeing approx 10k, failing that remove the M92 IC and retake the measurement your then looking for >10k after
Keep the EMMC disconnected going forward, such a low reading on the 1V8PDR will corrupt it.
Now I switched to my Fluke DMM now I measure 3,2kOhm with and without EMMC. But I measure the exact same on the known good board.
I measure on the top right inductor.
Itās no good good unfortunatley, should be approx 10k/13k depending on probe polarity, fluke or not, try letting the boards cool down prior to the reading, if you have a secondary meter to verify nows the time 