8850 Does not keep signal

[jagajutt]

Dear All,

I have an 8850 that when initially switched on gets signal and then after a few seconds loses it. I have:
1. Checked IMEI - def not the prob
2. Flashed v5.31 and Fatihorhans flash file (http://nokiafree.org/forums/showthread.php?threadid=6702&highlight=8850+flash)
3. Used Eeprom Tools 3 +4 to do the tests and it passes them all !!

What could the problem be ????

Regards

Jag

[riko_bananas]

is it your antenna switcher??

try reheating the thing or it could be CCOBA (dont have a monkeys what that is either)


this is just a guess from other posts i have read in the past i have never done this myself

Sorry Rich

[jagajutt]

@Rich cheers

I have also come to the conclusion that it is a hrdware fault. So to all the experienced (or not so experienced) hardware people out there ideas please.... I have used the Eeprom Tools "Test" option, but i assume this is mainly a 'superficial' test

Links to websites appreciated - as i cannot find any comprehensive hardware fault finding sites.

Best Regards

Jag

[chunkhead]

Have you updated FAID? Use the Knok95 Unlocking guide in the Forum FAQ! This may sort your problem! If not then you have a faulty antenna switch! You need to re-flow it or replace it! It's the small silver box on the top right of the pcb! If you place a sticky foam pad over it and re-assemble the phone, it may produce enough pressure for it to work!;)

[riko_bananas]

thats interesting to know chunkhead.. say if the switcher was broken would the only place to get another one would be from a doner phone or do people aucally sell such small components?

[chunkhead]

Donor phones are a good source, but you can buy them! Search on Google!;)

[Gurj]

I have an 8850 too, I get no signal neither. I tried puttin a sticky pad on the switcher, but it only worked for a few seconds and im back to square 1. Can't the old switcher be repaired or re-soldered? So where can we buy a switcher from ???

A friend indeed is a backstabber indeed.

[riko_bananas]

yeah you just need to get a repair shop to reheat the switcher if you have the sudden signal drop problem or do it your self with a heat gun, the component is silver i think according to the posts above, ive never done this myself im only going on what otheres have posted in other forums

Rich

[Gurj]

Ok, so I could just stick a soldering iron to the switcher for a while.
Is it recommended that I resolder the points on the switcher?

Where can I buy a replacement Antenna Switcher ?

[Gurj]

You guys will love me if I told you of a site that gives out FREE NOKIA SERVICE MANUALS. Just click on the manual u want and unzip it.

Check it out geezer's.

http://www.desatech.de/desaflash/nokia/

[Gurj]

Ok guys, I tried heating the switcher, I stuck a soldering iron to it for a good few seconds, but i still have no reception.

Where can i buy a new switcher from ?

[riko_bananas]

try searching on google.. please dont take my words for gospel i think your better waiting for someone more experienced to reply to your post.. i dont know that much, i dont want you to bugger up your phone becuase of what i have said

i asked this questions about getting nokia PCB components and apperntly if you search in google you can find them

using a soldering iron is really clumsy i think you need a heat gun really, and were not talking a heat gun that you would use to shrink heat shrink or melt glue, were talking a special small nozzled PCB one i think...

please wait for someone else to back me up i dont have a very big knowledge

SOrry Rich

[Gurj]

So how is a heat gun meant to solve the problem ? If the part is dead, then its dead. Hows the heat gonna fix the part ?

[Gurj]

So how is a heat gun meant to solve the problem ? If the part is dead, then its dead. Hows the heat gonna fix the part ?

[Gurj]

Earlier on in this thread, some1 mentioned a CCOBA, not knowing what it is or what it does...1stly its not CCOBA, its COBBA, and it only controls the Audio, Serial and Parallel data within the fone.

So the lost signal / no reception has nothing to do with COBBA. The wonders that a Service manual can do.

[riko_bananas]

well it iwll just make sure the connections to the board are good, one of them maybe dogey

i dont know i only know what ive been told sorry ! ask someone else !!!

[riko_bananas]

that was me who made the mistake with the cobba, sorry only trying to help.

[sergo_zmeia]

Mr. Gurj COBBA has relation with the signal....COBBA is mixed signal baseband IC for DCT3 phones...so to be sure it is not broken run a test with Eeprom tools...for You network problem...if there is two networks /900 and 1800MHz/ in Your country You can easy find out if antenna switch is broken..if there isnt two networks thinks are bad...
Two points: antenna switch or PA....try to reheat the PA if You lost all the network /I mean it dont appears any more ever for a few seconds/ it the PA If there is not change may be it is the antenna switch.
Hope thats help....
Regards!
Sergo_Zmeia