News Forum Phone database

> New Topic
> Reply
< Esato Forum Index > Sony Ericsson / Sony > General > ///Ericsson Forum - Infos and support - For help contact your local eriman! Details in the 1. post! Bookmark topic

Quote:
On 2007-01-01 22:52:00, EMS06 wrote:
Any other advice on what not to do or avoid? I've opened all my Ericsson phones except this one and it does look tricky.


have you removed all parts of the old catch? then you don't need to open the phone, the catch can be put in place without opening the phone

removing the catch from the T28 phone can be done without opening it as well, holding a finger on the catch (so it don't fly all over the room when you remove it..) while you gently use a flat screwdriver to remove it from the phone. If you want to be more sure not to break it, you can open the phone, follow the guide on http://uselessinfo.pwp.blueyonder.co.uk/dismantlet28.htm (you can use a small screwdriver instead of the original opening tools)

[ This Message was edited by: Cytech on 2007-01-01 23:15 ]
--
Posted: 2007-01-01 23:53:26
Edit : Quote


I have done it before and found the hardest part was getting the good one out without breaking it. Putting it in was really easy. They push in and that is it really.
--
Posted: 2007-01-02 00:06:30
Edit : Quote


The most important apart is where the batt is hooked in

This message was posted from a 6233
--
Posted: 2007-01-02 00:16:51
Edit : Quote


I hadn't opened the phone yet, thank goodness! Cytech and jcwhite_uk- you guys were very helpful. I've got my r320s in working order again. Thanks.
@Boba- thanks and appreciate the support.


--
Posted: 2007-01-02 00:44:00
Edit : Quote


@Boba:
Most of all defects at ///-phones can be found in the radio area, usually it is the transmitting part. Every sender/receiver has two things in common: the length and resistance of the antenna is specified by the frequency and bandwith the sender/receiver is working in. Maybe you tried once to use a long cable as antenna for your radio and realized, that the signal is poorer than with the original short antenna. This is due to a wrong length and resistance. Mobile phones work the same.

Wrong parameters for a receiver will only result in a poor signal. But a transmitter like our phones can be killed because the PA gets overpowered. Unfortunately Ericsson had a lot of problems with bad contact between the PCB and the antenna. Each series has their sympomatic problems:
- Series 2xx, 3xx or 6xx usually only die because of pulled off antennas by stupid users.
- Series 7xx, 8xx and T1x are quite resistant because the antennas are screwed and the connection is quite strong.
- Series Txx and Rxx have a very bad problem with the antenna: Did you ever open one of them? Remove the cap and you will find a thin plastic foil with some printed lines of copper. this is the aerial. Now look at the connection between the foil and the metal pin which comes out at the bottom: The pin has only been pushed trough the foil. No wrapping, no soldering, nothing else. This is a real poor connection. Now remember how quickly the surface of copper corrodes and you can imagine how long these antennas will provide a good signal.

The second big problem is that older PAs have no good power calibration. The Conexant RM009 (built in R320, T20, T28 and T29) for example gets very hot and therefor can die very easily. The Ericsson 403 xxxx PA (built in R310, S868, SH888, T28w, R250s) is another problem case since it has no big grounding pad to lead off the heat.

The only two models which differ from all others are the T39 and the T66/T600: If they can't find network it is usually only a problem with broken soldering balls underneath the BGAs. All you have to do is resoldering the processor and the phones works again. A small amount of T39 is unrepairable since some of them have their rf-processor glued to the board with epoxy glue. These processors can't be soldered.

r0sewhite
--
Posted: 2007-01-02 01:41:21
Edit : Quote


@rose thx for the great comment. as i rcall, in t39 /// used some experiences from the mi,itary area, afaik in case of the transmitter. seems that problem was solved later, cos for example with r520 i never had such problems
--
Posted: 2007-01-02 11:28:30
Edit : Quote


@Boba:
The T39 and R520 have the same rf-area. All components are the same. Both models have real good components. The no-network-problem at T39 is a mechanical problem, not an electronical problem: The rf-processor is placed at the point where the YES-key is on the other side of the board. The board itself is quite flexible and bends a little when you push the keys. The rf-processor has no legs as contacts like older chips but it has a bga (ball-grid-array). It looks like a matrix of small soldering balls between the board and the chip. If you bend the board too strong these balls break off someday and so you get a contact problem.

If you have a working T39 there is a very simple solution so you never will get any problems: Just put something between the rf-processor and the magnesia back so the board can not bend at this point anymore. Some people cut out a 7mm x 7mm piece from an old sim card. It has the right size (about 1mm thick). I prefer to put a little sticker on the chip and then put one drop of epoxy glue on the sticker. Ericsson solved this problem by sticking a small rubber pad on the processor on later models. Any solution will work. You just have to put something between the rf-processor and the magnesia back to prevent the board from being bent by pressing the YES-key.

The R520 only differs in one thing: Ericsson already knew about the problem and designed the contact surface between board and magnesia back so that all relevant points are strong enough.

If you speak german you can find a complete repair instruction for the T39-problem on my website at www.e-zones.net.

r0sewhite
--
Posted: 2007-01-02 12:04:53
Edit : Quote


@ r0sewhite,
Your knowledge regarding these issues and your informative posts in general are indeed a great help around here. It is appreciated.
--
Posted: 2007-01-02 12:13:53
Edit : Quote


thx for the link. did u noticed, that there are differences between malaysian and swedish fones? i do understand, the the malaysian ones got pinted keypad for example to reduce costs, bus why is the light so dimmed on those compared to the swedish ones?
--
Posted: 2007-01-02 12:15:23
Edit : Quote


@all r520 proto owners:
what firmware do your phones have? my is R4A008, but it was updated by it's first owner because the bluetooth did not work, but it didn't help.
do the proto phones have different startup animation, or some other changes?
--
Posted: 2007-01-02 13:17:27
Edit : Quote

---

New Topic   Reply

Forum Index