Flash 100% ok in dead 3310 but still no power

[Burnt Cobba]

this one still has life in it ... seems no software problem but still no pwoer

what component if any is bad pls?

thanks all
alv

[ceedee]

if you will try few times mobile give you Contact Service. Generally it's faulty COBBA.
Regards

[Burnt Cobba]

so in other words Cobba has to be replaced

well from my experience even if Cobba is removed the phoen will power up anyway with Contact Service showing up



:confused:

definetely it wont become worth it to fix it then

thanks anyway mate
alv

[vule]

Hiya

Cobba does not do anything with power on ( except if it has short circiuts in it so ccont prevents phone to switch on )

First, if flashing ok but no powering on check eeprom...U might erase it accidentaly. So flash in new eeprom and check ( eeprom start adress is 003D0000)...

If still dead even with new eeprom try to read out flash and compare it with file u flashed in....It could be that some location in flash is faulty....

Try to resolder hagar ( do not reflow it ! ), 'cause hagar can also prevent phone from power on...

Next thing to check is ram...It can be half way faulty so it boots cpu normally ( that's why u can flash it ) but when power on needed it stop responding...

I assume that ccont is ok ( because u said u can flash it normally )

Check also L 513 ( under metal cover n middle - consult service manual ) and L201....If broken or bad soldered phone can't power on....

Check power consumption of phone ( off 2-6 mA )



Br

Vule

P.S. If no succes mail me private

[Inhuman]

Originally posted by ceedee
if you will try few times mobile give you Contact Service. Generally it's faulty COBBA.
Regards

Sorry...but what is cobba?? i need to know

[Burnt Cobba]

Vule i have a problem in all this. What is the easiest way to reball? and position the BGA chip properly without any risk.

Also what tools will i need to definetly make my homework ok? Asking you this just to know if i have the right tools. BGA resoldering is very hard indeed.

The idea of not gettign the phoen to pwoer back again ok lets me down :(

thanks Vule for your valuable help and support mate
alv

[vule]

Hiya


U need hot air station ( i use some home made but chinese quick850 will be good enough ), bga rework kit ( tin mask with holes ), some sparkle paste ( i use hisatomi electric paste ), some flux, soldering iron and magnifying glasses ( microscope if u can effort it ).

There is one rule for good bga rework - everything must be VERY clean !!!

Take off bga chip, put it in slot of bga kit, apply some flux and clean rest of old balls with soldering iron. Then use hot air to remove rest of flux together with dirt ( use high air flow ).
Put bga kit mask on chip, apply sparkle paste and fill all holes of mask ( do not use rubber which is supplied with most of bga kits, use knife or something similar ).
Keep mask steady and apply hot air ( play with temp and air for best results - for quick AIR - 3 and temp 5 ) untill u see balls forming in holes. then remove hot air and let balls cool down.
Put something under mask ( chip is now attached to mast ) to keep chip 3-4mm above working surface and apply hot air again untill chip fall out of mask. Then check balls ( if all of them are there and all have almost same size ).
Use flux and soldering iron to clean board from old balls and dirt, apply some flux again and then center bga chip in it's original position and apply hot air untill u see that chip slightly moving ( if u don't center it exactly on place it will flow on balls to it's perfect position ). Then remove hot air and let board cools down...

That's it, just keep bga slot and mask very clean....

Not so hard, aint' is ????


BR

Vule

[Burnt Cobba]

mate does heating the chip together with teh massk on it damage the mask?

usually i try to remove mask so as to leave the paste on it and then heat... i fidn it difficult to kee pthe paste onto the chip.. that is where is my problem... i did not know that the mask shoudl e left onto the chip and heated together.

am i correct or not pls?

thanks Vule
alv

[vule]

Do not remove mask, heat it together with chip....I use same mask for a year approx and still is ok...And i make more than 10 bga chips in one day so it's pretty tough use of it...

As i said: when balls are formed, let it cool down and then lift mask and chip for 3-4mm and heat it again untill chip falls out from mask on bench.....


BR

Vule

[Burnt Cobba]

ok then i ll try that

hope mask wont get deformed then

wil ltry asap

thanks mate
alv

[Burnt Cobba]

Hope this topic is not outdated now but from last time i managed to get hold of resoldering back BGA chips. But not reballing the chips. I am luckily enough to kepp the existing balls without destoryign them thanks to the flux.

however i still am having the same problems as regasrds with 33X0 and 82X0 where there is the RF problem... either full for 10-15 seconds then none or no RF at all.

resoldered back Cobba, HAGAR and a dozen other components as expalined in the service manual. Yet still no RF activity at all. Manual search takes a lot of time till it "times out" and says no network found.

What else can i do or change? :eek:

thanks 2 all of u for the help , patience and time
br
alv

Ps. Is ther someone who sells HAGARs and COBBAs? maybe already reballed :)

[vule]

Hiya


U need to make new balls....Old balls are not good anymore ...Maybe they are all there but their electrical characteristics are changed due to heating and moving.

Did u changed PA???



BR


Vule

[Burnt Cobba]

yes i changed Pa but it is Cobba most probably then :eek: Sometimes i meet aslso MS_ID error. It is cobba realted i think too... even after resoldred it back it wotn work.. seems due to the old balls

i thought by leaving the old balls there they could be reused

Resoldeing teh BGAs is not a difficult task .. infact the BGA chip itself indicates you whether it is ok or not by aligning itself automaticlly after heating for some time.

The problem that i am facing is then the reball part :(

That i am making a mess.

I tried on a hagar and cobba size chips... place the paste, smooth it out over the area to fil lthe holes.. then i try to heat with stencil over it... the balls form .. i let it cool but still they wont stick to the chip :( after i let it cool down.

if anyone maybe Vule has some video clip or something to give me an idea how to do the reballing it would definetely kick the problem out.

thanks a lot
alv

[cmk]

your phone may be 3330 32M flash so can flash but cannot on

[cmk]

all nokia phone power up no need cobba
i meaning is take out cobba the phone still can power on but it can get C/S

[.::AkhavanGSM::.]

resolder hagger ,ccnont and cobba .
If neccesary change them.
I had same problem with some phones.and changing this 3 ic's solved problem.

[biberuli]

u need change or resold the ccont

work 100%

[.::AkhavanGSM::.]

I had same problem.
resolder all bga's (ccont and hagar specially)

[JONREB]

this the solution to you 3310 dead phone, just re-flow the hagar ic after that u try to on the power and smile(",)
have anice day my friend.........