LG G4 Bootloop problem !

[svchost]

i try everything to solve with software , different boxes , flashing tools process completed sucessfully but phone not start, maybe have hardware problem please if know anyone any solution can share with me .

[jamesjerss]

Specify your model number of g4 device.

[svchost]

Dear cwcast solve my problem thank you again sir phone realive.

[jethzkie]

how you solve your problem, can you share here? thanks

[misulikkk]

Reheat 2-3 minutes ( 285 degrees) cpu, and the ram, tested on 3 devices, after that all ok. If you flashed the phone and don't have download mode : remove the battery, press volume up, insert usb cable, wait for the phone to give a battery error- question mark, keep pressing vol up, now insert battery, and way with the vol up until you see download mode. If no download mode, short the contact pins on the phone and retry the method

[kose2ik]

So as not make things worse initially, and would need to first make a copy of the data. Then use first this metode temporary (get data out off phone) is cool town moderboard with vacumcleaner or compressed air. This CPU take bootloop if outside/surface temperature is over 70* (the internal temperature is much higher than the surface) (air cool town, stable temperature ~30*C (CPU-Z all sensors show: 25*C)) (if temperature rise of metal / material expands (and may be lost tin contact)) (My device doing reboot/bootloop when CPU-Z sensors show: ~35*C)

Service manual LG-H815 page 96 ("9. PCB LAYOUT") is writed problem chip: U2100(MSM8992)(is layered beneath the RAM: U3100 (~3GB)) / U3200(eMMC)(NAND Flash (~32GB)) if device "No Booting/Crash"
So it may be a problem in the three chip (in one of them or in all). While there may be a problem, not a tin or soldering, but inside the the chip or motherboard (However, the heating can improve the contacts (deformed by the heat) (or make worse))

(My device: U3100 is chip: SKhynix LPDDR3 H9CKNNNDATMTDR-NUH FBGA(216ball), 12mm×12mm, 8Bank, 1.8V/1.2V/1.2V, 24Gb, 192Mx32, speed 1866) (My device: U3200is chip: 1516KAE THGBMFG8C4LBAIR VE9536 CHINA)

My chip picture bad work LG G4 H815 LG-H815 goo. gl/photos/HYHWGbS7NQit5Fnk6 and goo. gl/photos/Vt88Do4uxB7gR65X9

temporary (get data out off phone) is cool town moderboard with vacumcleaner or compressed air. This CPU take bootloop if outside/surface temperature is over 70* (the internal temperature is much higher than the surface) (air cool town, stable temperature ~30*C) (if temperature rise of metal / material expands (and may be lost tin contact))

reheat CPU(&MEM) solderballs or reball youtube. com/watch?v=F02SgZN4L1Y

FBGA 216ball package (Adhesive-bonded/poxy) Underfill CTE mismatch is a big problem for flip- chip assembly, the thermo-mechanical stress breaks solder bumps. The solution is to add some underfill between the die and the substrate. Underfill resins are loaded with silica and have CTE around 30ppm / K Technical aspects23
google. com/search?tbm=isch&q=Underfill+pop (without spaces mega . nz / #!SI10marY! C0wMUTDTDp8gNiGaoeRWQ5PvKpwna9okJpo - AS7OO28
ifixit. com/Teardown/LG+G4+Teardown/42705

(This device: U3100 is chip: SKhynix LPDDR3 H9CKNNNDATMTDR-NUH FBGA(216ball), 12mm×12mm, 8Bank, 1.8V/1.2V/1.2V, 24Gb, 192Mx32, speed 1866) (This device: U3200 is chip: 1516KAE THGBMFG8C4LBAIR VE9536 CHINA) ( This device: U2100 is Qualcomm Snapdragon 808 (s808 / MSM8992))

[djstasgits]

Just replace replace or reball cpu + ram and fix imei