Quote:
Originally Posted by Dave.W  These photos show exactly that. Oscilloscope makes you "look" proffesional, and means you can charge more money to run a repair course.
But really, it is useful?
Personally, I dont think so.
I use oscilloscope in other areas, when designing circuits or creating test procedures.
Also I have repaired many many phones since < 2001.
Guess how many times I used oscilloscope on GSM board? none.
Your phone is dead? -> connnect on flasher and see error messages.
Your phone has no signal? -> do manual network search, is problem Tx or Rx?
Of course, we know the charge ways, signal ways, keypad ways from simply looking at the circuit board and using 10 years built knowledge working with these devices!
This method is fully tested in a repair centre, there is NO REAL NEED for 'scope! |
sorry sir,,,
im really like this thread cause we can talk each other and hope can be good study about what we discuss here....
I use osciloscope not only to make me look profesional.... but I use it cause i need it....
i have 2 osciloscope and i use it every day specially for Signal and Dead phone.....
Why i use it????
cause we know that all of voltage and data at a phone can be measured....
so if we wanna know an IC is bad or good we have to know that the out put of the IC is correct....
for example,
For Dead Phone in WD2 like 6600, with 1st boot error message at Flasher Box Like UFS, we must measure some indicator that can make our Phone to be 1st boot OK
What is that????
The conditions to make 1st ok when flashing is :
Vio = 1,8 Volt
Vcorea = 1,5 volt
Vana = 2,8 Volt
Vr3 = 2,8 Volt
PURX = 1,8Volt
Sleepx = 1,8 Volt
Sleep Clock = 32,768 Mhz
Rf Clock = 26 Mhz
If all condition above normal our phone must be 1st ok, if still error the problm must be at CPU
In Signal Problem, Im very depended with oscilocope....
Why???
cause in signal problem many indicator that cant measured with Multi tester, but must with osciloscope like :
Rx i / q from Rf Ic to UEM
RF Bus data from CPU to RF ic
Control VCO from Rf Ic to VCO, etc
if one of this not normal, our phone must be NO RX....
How we can see that indicator with multi tester???
how we can analysis a damaged without this measurement????
thats why i use osciloscope... cause its very important to make me sure about a fungtion of some ic... to know its damaged or not...
Not For High Cost, Not For Look Profesional... but to make me easy in working....
Sorry... just for share... and i hope we can support each other...
regards