View Full Version : T20 RF processor problem. Very strange!
johny3310
06-22-2003, 01:12
I have T20 with good signal, but call cannot be connected,
onli silent "click" from speaker.
So, i put new RF processor - and now no signal at all!
So i tried another new RF proessor - again no signal.
I tried to change PA, Ant. switch, Multimode adapter - still no signal.
When i put original RF processor back, i have signal, but cannot connect a call.
I have tested these two new RF processors in good phone - they work OK.
I checked lines on PCB arround RF proc. on my bad phone with microscope - everithing looks fine.
Soldering isn't problem, i am 100% sure about this, i allready
changed more than 50 this chips without problems.
Any idea?
If you have "puk" in speaker, that could be PA, RF proc. , or RX/TX mixer problem.
Usualy, this is coused by bad soldering under PA, or bad RF processor. But in your case, i have no idea at all. . .
Or try to rehot 1011120/4CR1 sometime is problem in him,because he is multiprocesor for all(mic,speaker,network too),but before all check antena conector,maybe is problem in bad contact...
Last two days i have more two T20 with "click" in speaker and "searching network",first i rehot DSP and after that i pick up him and make new pins and Legija belive me-they stil work!!
Hm, of course, that can be reason, too.
But, for me, reballing DSP is needed only when you have no sound in speaker.
Shi.ty ericsson phones . . .
gsm-lord
06-29-2003, 20:47
Originally posted by legija
Hm, of course, that can be reason, too.
But, for me, reballing DSP is needed only when you have no sound in speaker.
Shi.ty ericsson phones . . .
for no sound u must reball multimode convertor not dsp
themobileking
07-02-2003, 21:44
I had many T28's and T20's with this problem ...and frankly ..i tried everything ..PA ...RF processor ....mixer ..antena switch ...antena connector ...software upgrade/flash..finally i gave up ....i could not solve the problem ....but some phones were easy ....i would just change the RF processor and it would work well.....i remember in 2 phones I changed the Power IC and the "click" problem was solved...I thought that i had solved the fault ...but when i tried other phones ...:(.....no it was no use ...I have never been able to solve this problem 100%
L_DIM2003
07-03-2003, 14:23
I had many T28's and T20's with this problem ...and frankly ..i tried everything ..PA ...RF processor ....mixer ..antena switch ...antena connector ...software upgrade/flash..finally i gave up ....i could not solve the problem ....but some phones were easy ....i would just change the RF processor and it would work well.....i remember in 2 phones I changed the Power IC and the "click" problem was solved...I thought that i had solved the fault ...but when i tried other phones ........no it was no use ...I have never been able to solve this problem 100%
yes, you write
this is problem very actually fo 2618/2628 too. very bad phone:)
sometime try to rehot flash on A2618 or 2628......look crazy.....but try,dont ask me how but some of them still working!
genocite
07-06-2003, 11:00
i think cpu also controls signaling and too bad the t2x phones almost had the cpu glued all
Maybe i`m wrong,but i know there are 2 different versions of boards on T20.
One of them have a type of PWR AMP and a ICRF 11033,like T28,and the other one have another type of PWR AMP,and onether ICRF 3004CR1C,like 1018.Maybe this is the reason for incompatibility.
L_DIM2003
03-04-2004, 08:04
yes, there is two different boards for T20/T28
yesterday i had new problem with this is phone (T20)
from this phone i can perfect make call with one operator (tele2), also this phone show perfect parametrs on both bands with gsm tester, but with other operator it can't find net - net on lcd full and drop down, and again... same time phone can find net, but without calling...
i think problem in frequency generator or in sintezator . i think that there is same frequency offset in phone and for different operator this is parameter may be very critical.... for one operator this is offset is wide and phone perfect synchronization with BS, for other operator this is offset little - and fail to connect...
ok, i try change RF, 13 MHz, PA, all cmd arround 13 MHz (varicaps, capacitors...), reflow AD/DA converter, rewrite eeprom (but i think that it not help :) ), also change sintezator D300...
not help :cool: