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Ericsson T28 FAQ


This FAQ list contains a collection of frequently asked questions and answers about the Ericsson T28 mobile phone. Details are sourced from newsgroups and Ericsson's web site. Please direct enquiries to me using this page, or e-mail Try out the Ericsson T28 poll here. If you would like me to add another choice in the poll, enter it as an opinion in that page.

Last update: 3 June 2007 1439hrs


Use any or all information in this page at your own risk. Do not try to disassemble or reprogram your phone unless you are sure of what you are doing. I do not work for Ericsson and any other company mentioned here unless expressed otherwise. Digest this page with a grain of salt, because nothing here is necessarily true.

More good stuff about news and views that matter to me, check out my blogs.


What is the T28?

It is a mobile phone from Ericsson which was released in October 1999. At that time, the T28 defined the latest mobile phone technology available from Ericsson.

What does it look like?

You can check that out by going to Ericsson's web site, mentioned above, or click on the following for photos taken badly by yours truly, using a Kodak DC240 digital camera. See more at the T28 Gallery.

[JPEG image, 30K], requires JavaScript] [JPEG image, 30KB, requires JavaScript]

Where can I find a demo on-line?


What are the different models of the T28?

T28s GSM900/1800
T28 World GSM900/1900
T28sc GSM900/1800 with Chinese language support

What are the dimensions and weight?

97mm x 50mm x 15mm. Without a battery, it weighs 60 grams. It weighs 83 grams with the ultra slim battery included.

What are the specs of the different batteries?

Item Type Capacity Weight Talk time (max) Standby time (max)
ultra slim battery lithium polymer 500mAh 23g 2 hours 50 hours
slim battery lithium ion 650mAh 29g 2 hours 45 minutes 70 hours
high capacity battery lithium ion 1400mAh 54g 6 hours 150 hours

What is a lithium polymer battery?

It is a battery technology which uses lithium as the energy conductor and a polymer substance as the electrolyte. Compared to nickel metal-hydride batteries, lithium polymer (LiPo) batteries are more efficient, weight can be 50% less, and volume reduced by 10% to 20%.

The polymer used is a moldable gel which can form irregular-shaped batteries. Thus, empty corners and gaps in the housing of a phone, for example, can be filled.

The LiPo battery used in the T28 has a lower voltage of 3V compared to many other phones' 4V or more. IMHO, it is the advance in lower power consumption of the latest semiconductor components, such as surface mount chips, that helps to increase operating times.

Can I use accessories from older Ericsson phones with the T28?

No. The accessories for T28 fit differently and contain intelligent circuitry which is used exclusively with the T28, and possibly future models in the T series.

What are the accessories to be released in the future for the T28?

Portable Handsfree with MP3 Player
Supplied with stereo earphones and a removeable memory card, playback is muted automatically before and after a call. Does not require extra batteries. Release date: mid 2000.
Bluetooth Headset
This headset uses Bluetooth technology to link with the phone using radio waves. A plug-in unit is to be connected to the phone though. It weighs about 20 grams. Release date: mid 2000.
Previously released for older phones, this device for efficient SMS and e-mail messaging will be available for the T28. Release date: mid 2000.

Can the antenna be replaced? [new]

The general idea is yes. Ericsson has something called a "high performance antenna IAT-10". Dr. A. Merrington has this to say about it:

"The details are for NPI (part of the Airstream network) in Michigan but I would guess its true for any service area and service provider.

If you are in an area with a reasonably good signal (a three or so on the T28 signal intensity meter), you will get a stronger signal. It will boost a 3 to a 5 (max). If you are in an area with a very weak signal (a one or so) you get a slightly better signal - a 1.5 (flashes between a 1 and a 2) to a 3. If you are in an area with no signal, it won't do a thing. I lived about half a mile beyong the signal limits from two towers and now, with the IAT-10, I get a weak signal in my yard. I still can't pull a signal into the buildings.

Is it worth buying? For me it was because, as a I said, I lived just outside the old service area, now I don't. The other thing I forgot to mention is that it seems to hold onto signals whilst driving in the car better with fewer dead spots. It offers an incremental improvement rather than a significant improvement but if that's all you need, then it'll work for you.

I used to run a 0.6Watt Motorolla Microtac with the 3Watt in-car booster. Now that set-up offered significant signal enhancement. The IAT-10 is not in the same league."

Here's a list of sites which sell this thing (some may be outdated):

How should the battery be charged initially?

Out of the box, the battery may have a little capacity, so you can play with the phone immediately after you exit the shop :-). You should charge the battery fully, which may take longer than subsequent charges. Some say that the first charge should be done for 16 hours. The important thing to note is that after the first charge, the performance of the battery is not indicative of its normal operation. Subsequent charges will bring the battery to its real performance.

How should voice dialling be configured?

After you have selected a number to add voice to, the screen will display the message to prompt you to speak after hearing the tone. By the time you selected the number, you should hold the phone in the position you would hold it when you voice dial in the future. Most likely this position is by holding the phone to your ear and mouth. It is best to record the voice in a quiet place.

What does the display of a triangle with an exclamation mark in it mean?

It means the network has turned off encryption for your calls.

My T28 fails to turn on no matter what I try. What should I do?

This is a common serious problem. Several possible causes are: faulty motherboard, faulty battery connector (the 5 gold pins). So far, anybody would tell you to go visit your service centre.

My own T28s was sent in for replacement because of this problem (Feb 28 2000). Customer service said that for new phones such as this, manufacturers tend to readily replace the unit. I'd suppose this is more economical and allows customers to have a better version of the unit. I was told not to overcharge the battery by disconnecting the charger immediately after charging is complete, but I'm not sure how that can help. I've got a Jan 2000 version of the firmware, which I'll put up some news when I find any differences.

My active flip opens by itself involuntarily, or is loose. How do I fix this?

This problem typically occurs after one or several months' of usage. Bring the phone to an Ericsson warranty service centre. If you want to fix it yourself, take a pair of long nose pliers, grip the round little stub on the right side of the flip and bend it upwards slightly (with the screen facing upright to you). You may want to hold the flip firmly to support the bending. Some folks say that this is what the service people do at Ericsson.

Paolo suggested a quick and cheap fix that uses plastic/super glue. With the flip open, put a drop of glue on the stub. Wait for the glue to cure completely; you may use a sheet of paper to check. Now, the flip should click when closed. My concern is whether the glue's chemical reaction with the plastic stub is a bad thing.

One point to note is that you must use only the flip release button on the right side to access the keypad. Do not use your fingers or thumb to pry open the phone as you would with the previous Ericsson phones with flips (e.g. GF788).

How many voice labels can there be in the T28?


Where can I find melodies to try out?

Check out It has a decent collection of melodies for Ericsson phones and a program that can play them on your computer before you enter it into your phone.

Ericsson has a ShockWave applet on their site. Look for "Tune Your Phone".

How do I check the firmware version of the phone, or how do I access the "Service" menu?

In standby mode, press >*<<*<* (< means left arrow, > means right arrow). From here, you can select the following:

  1. Service Info
    1. SW Information
    2. SIMlock
    3. Configuration
  2. Service Tests
    1. Display
    2. LED/Illumination
    3. Keyboard
    4. Buzzer
    5. Vibrator
    6. Earphone
    7. Microphone
    8. Real Time Clock
  3. Text Labels
  4. Flip opened

What are the possible firmware versions that users have found?

  • 000823
  • 000809
  • 000515
  • 000113
  • 991022
  • 990831

What is the pin-out of the phone?

Try this URL: <URL:>

Where can I find the manual on-line?

Please download directly from this FAQ site. There are two choices:

What are the limitations and peeves of the T28?

This is going to be the longest section...

  1. No predictive text input.
  2. Only tone and click SMS alerts available.
  3. Light does not turn on when left slide button is activated.
  4. Ring volume is still not significantly louder than previous models, such as 7xx series. However, someone told me that Ericsson is adhering to a safety standard of not having the ring volume of their phones to be higher than a certain decibel level.
  5. Number and size of templates are limited to less than 10 templates and not more than 30 characters respectively.
  6. Not able to choose different ring signals for each profile.
  7. Clock time will be lost sometimes when battery goes flat.
  8. No caller groups, which can be used to assign different ring tones for different groups of people/numbers.

What is BlueTooth?

It is a wireless communication specification set by several bodies, such as Ericsson and IBM. It features low power, short distance, and intelligent communication between devices, such as phones and palmtop computers, via radio (2.4GHz). For more information, see and

What are the best Tetris scores?

Yes, some of you may say that it's a waste of your lifetime, but there are people who get really bored on the train or bus...

  1. 1000026 (10) by Kim-Serebriakov Y. Yuri
  2. 477825 (09) by Jan
  3. 148372 (07) Cero
  4. 118988 (09) by Anže Stankovič

You can find more incredible scores at this site.

What are the relevant newsgroups that I can go to?

Try and alt.cellular.gsm.

end of FAQ

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