The True Value Of Hutch Prepaid

[netfreak]

QUOTE(vebmetal @ Jun 3 2006, 12:58 PM) [snapback]53103[/snapback]
Someone was telling me that in places like Palika they can convert a CDMA phone to GSM. I have no idea whether this is technically possible and whether they just misunderstood it or something - but does this really happen? If so, can you convert a GSM phoen to CDMA too?
[/b]

Yes it is possible.

chip that handels wireless GSM / CDMA / TDMA /PDc /PHS is just a "module" on a phone.

You can swap a GSM "module" for CDMA and vice versa.

It would not make sense for Nokia / Samsung etc to build two saperate production lines for CDMA and GSM. So they build just one model and install one of the wireless modules. Commercially it might be sold as two models though.

 

[aniketvb]

Well thats what I am saying precisely. The chip used for network access is different for CDMA and GSM . , and there is very small chnace of them being pin-for pin compatible. Moreover.. ..If you know well, mobile phone PCB's are made using Surface mount Technology which needs very sophisticated fabs and machinery, so you cant just change the chips as in ordinary electronic gadgets. Its not possible to change it at your local repair shop.

 

[netfreak]

QUOTE(aniketvb @ Jun 4 2006, 06:03 PM) [snapback]53235[/snapback]
Well thats what I am saying precisely. The chip used for network access is different for CDMA and GSM . , and there is very small chnace of them being pin-for pin compatible.
[/b]


These modules are normally available from TI. And used by a large number of handsets (e.g. Nokia, Samsung). some baseband chips even have both CDMA/GSM built in (e.g. DragonBall™). And eprom controles which ones are allowed.

In fact, baseband chips used in low priced handsets boards (e.g. Used by Reliancd for 500 Rs cellphone thing) are completely replacable by GSM ones.

QUOTE(aniketvb @ Jun 4 2006, 06:03 PM) [snapback]53235[/snapback]
Moreover.. ..If you know well, mobile phone PCB's are made using Surface mount Technology which needs very sophisticated fabs and machinery..........
[/b]

No, SMP can very well be handeled with "Hand soldering". These tutorials show us how:



1. http://www.speleogroup.org/files/SMT-boards-sg.pdf
2. http://www.twyman.org.uk/PCB-Techniques/index-frame.htm
3. http://www.smta.org/ (Look for Hand soldering safety instructions and lots of useful info)
4. http://www.seattlerobotics.org/encoder/200006/oven_art.htm
5. http://www.robotroom.com/PCB3.html


You can compare that with OMAP1510G (TI) chip used by Nokia and Kyocera. This one has pins large enough to be hand soldered.

 

[smartbuddy_82]

^^^ Wow thats too technical man!

 

[jayesh]

quite an informative post .. not for the faint of heart. though with the rates of cellphones being as low as they are and second hand handsets to be had even cheaper .. no real point

 

[aniketvb]

Great info man Netfreak!! Truly awesome.I had said what I said coz my NGage QD was spoilt in the 26/7 floods last year and the Nokia Care guy said that he cannot swap individual chips due to the SMP fabrication used and I will have to replace the entire PCB for 7K Rs!! That was idiotic considering a new one was available for 7.5K at that time!!!!So does anyone know any place in Mumbai where such jobs are done so that I can get my N-Gagae fixed. I still have it

 

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[max]

whoa thats great info netfreak aniket, yes, Hutch was the first one to die in the 26/7 rains. My mum's reliance worked throughout and it died finally after 1 day. But it came back pretty quickly!