I have disassembly and repaired the lenovo k900

Hi guys i bought this device a few days ago, fascinated by the design and performance, I wanted a phablet 5.5 and I could not resist at good price but when it arrived it had audio problems.
I thought the firmware could have problems, but it worked in bluetooth handsfree and then I did not understand why.
Having experience in microelectronics with my work repairs transceivers I could not resist and I opened it.
Well I managed transaction, it works fine now and the owners of this beautiful phablet who want to see what's inside you can watch the album that I uploaded in the profile.
Greetings to all. max

Pardon for the foto , update directly on post now .

1 back of K900 with 4 torx screw and his screwdriver T06x50
(turn the screws to the left and then take them off and put them in a glass so as not to lose them)

2 how to separe live parts from bottom with razor blade
(insert the blade in a very kind and gentle, making a small force to the outside of the body until they snap the little plastic teeth that hold the body of the display with the shell, there are 3 teeth on the short sides and 4 in those long)

3.1 internal of bottom
(the inner part of the shell contains the contacts for the antennas and for the metallic screen)

3.2 all in one after open
(around the block phablet, we can see the 2500ma battery, the motherboard with L-shape, a lower block with micro usb, speaker and microphone, and an upper block with cameras inside and outside, proximity sensor, LED flash and the small headset, the vibrator has a round shape)

3.3 allin1 without back
(view of the whole, is very compact and simple, and the distribution of the components makes it easy disassembly and reassembly)

4.1 remove battery
(the battery is simply attached to the body with a small layer of double-sided adhesive, easily removed by pulling the tab transparent and removing the connector with a toothpick, making a slight force to lever)

4.2 zone two camera , earpiece , vibrator and proximity sensor
(to remove the motherboard, unscrew the small black screws with a Phillips screwdriver, there are 7 screws, one is covered by a sticker type security seal around the LED flash, on the other hand to remove the upper frame of the camera there are 2 white screws, the I have not removed the bottom for comfort)

4.3 remove small motherboard
(pay attention to the layout of the connectors and remove them again using a toothpick to avoid damaging the delicate tracks of the circuit, remove the motherboard and place it in a safe place, preferably on a sheet of paper and not plastic electrostatic)

5 back display dissasembly back wiew
(after releasing the back of the display from the motherboard and the top frame I discovered that the small headset was placed upside down and the contacts did not touch on the slopes of the circuit itself, I measured with a multimeter and it was ok 31 ohms , helped by a lens I checked on the contacts of the circuit if this were the marks left from the headset but were not present, a clear reference to a wrong installation)

6 rear of earpiece with contacts and reference
(the offending piece, you can see the notch and the corresponding joint in the display, well, when I opened it was the opposite, in fact the phablet worked with Bluetooth and Handsfree)

7 reassembly and test before closed
(I reassembled everything by reversing the procedure, taking care to insert the camera frame by repositioning the headset correctly, the vibrator and by matching with a lot of patience and chassis backplane, repositioning and tightening the screws excessively , reconnecting the battery and inserting the sim I turned it on, I checked that it worked by calling the remaining credit service , then I turned it off and removed the sim to close permanently)

update

XtriFe said:

thanks, where do we find the pictures ?

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Sorry , i update the thread with all procedure directly on post

Please, if I can help with my experiments this beautiful community are more than happy to share them

Sent from my Nexus 4 using XDA Premium 4 mobile app

Replace for AleSSi0, for digitalizer you tell me the toucscreen?

Replace for kensami, the part in question is blocked by a circuit board in a a square side of front chassis

Ciao AleSSi0, io ho aperto il K900 pochi giorni dopo averlo acquistato perché non andava l'auricolare è pensando che fosse il firmware ho anche provato ad aggiornare alla 4.3 con una viberom_v1.0_1411_ST_K900 trovata in un forum Lenovo ma è solo inglese e cinese e fra l'altro ha anche qualche bug, ci sarebbe il lavoro di QuBeX da seguire ma adesso penso che sia impegnato con gli esami , per il toucscreen o display ti posso dire che quando l'ho aperto sembra tutto un pezzo con il telaio perché appunto il telaio è il retro del display dove ci sono le schede montate, mi dispiace ma non sarà facile trovare ricambi per questo device.

Lumimila said:

Visto che qua si parla anche in italiano, vorrei chiedere qualcosa: il mio Lenovo K900 ha un problema con la camera. cuando tento di usare dece: "impossible to connect to the camera". Lo apro il telefono senza problemi pero non posso riparare. Ho trovato su internet (Aliexpress) una nuova camera pero ho paura che non fozionera ancora. I miei dubbi mi vengono perche non funziona nemenno il flash. Ho provato di staccare la camera e tentare di usare il flash pero niente, non funziona. Che ne pensate? Il problema e di flash e poi viene implicato anche la camera? Grazie. scusa la lingua.

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Ok Lumimila , i reply in two language for respect the rules of xda forum

You should check the firmware version of your K900 because when I received it from tinydeal was not different applications, they got stuck in the launch and I had to reboot several times but the blocks were always frequent.
My rom was multilingual, but the translation into Italian was really painful, then the headset did not work and before I go crazy with the updated method SDFUSE with a rom found on a lenovo forum, only Chinese and English.
VIBEROM_V1.0_1411_STK900 version 4.3, after the flash and after reinstalling the various app despite the only two languages ​​should be much better.
So before you go and touch the particular hardware are difficult to find and replace, try a different rom, made ​​a backup of important data and evidence, waiting for a rom Multilingual valid and updated type V8 QuBex. Let us know the result, thanks.

Tu controlla la versione del firmware del tuo K900 perchè quando io l'ho ricevuto da tinydeal aveva diversi problemi con le applicazioni , si bloccavano al lancio e ho dovuto riavviare diverse volte ma i blocchi erano sempre frequenti.
La rom presente aveva italiano ma la traduzione era veramente penosa , poi dopo avere scoperto che l'auricolare non funzionava e prima di impazzire ho aggiornato con il metodo SDFUSE con una rom trovata su un forum lenovo , solo cinese e inglese , non ho trovato di meglio al momento .
Con la VIBEROM_V1.0_1411_STK900 versione 4.3 , dopo il flash ed dopo avere reinstallato le varie app nonostante le sole due lingue andava molto meglio ed aveva problemi solo con app facebook ma l'auricolare non andava ancora e dopo ho scoperto che era stato montato al contrario.
Quindi prima di andare a toccare particolari hardware difficili da reperire e sostituire , prova una rom diversa , fatti un backup dei dati importanti e prova , in attesa di una rom multilingua valida e aggiornata tipo V8 QuBex . Facci sapere il risultato grazie.

Hi svvv, I do not know if there is a larger battery to replace your smartphone because the battery capacity is determined by its size and the space available is just that. Another problem is the difficulty in obtaining spare parts from China. I thing a good rom can extended the battery life, my K900 now is on from 7.00 am to 8.00 pm with a moderate use. You must be in st-by for a new firmware!

Lumimila Hello, I understand your problem but do not know a lot about this device yet, for me it was a test buy this device, I had only Nexus so far. I do not think that a connector can be responsible for your problem, when it happened the defect you mentioned?

Ciao Lumimila, ho capito il tuo problema ma non conosco molto bene questo device ancora, per me è stata una prova acquistare questo device , ho avuto solamente Nexus fino ad adesso . Non credo che un connettore possa essere responsabile del tuo problema , quando è successo il difetto che hai menzionato?