[Gta04-owner] Earspeaker, Vibramotor

[Dr. H. Nikolaus Schaller]

Hi,

Am 03.03.2013 um 14:35 schrieb Hermann Schwärzler:

> Hello Everybody!
> 
> I am an owner of a gta04 (a4) but not of an GTA02 or similar so I am
> lacking some parts to have a fully working phone.
> 
> Some days ago I found an old non-working Sony Ericson T230 while
> rummaging in the "potential toys" drawer of my kids. I disassembled it
> and found two parts that might work with my gta04:
> 
> 1. An earspeaker labeled "LTR711B" (see attachment "ltr711b..."). It is
> rectangular in shape but seems to fit into the case (I am using a 3D
> printed one) if I take a sharp knife to square the circle that normally
> takes the earspeaker. I plan to solder/glue some kind of "adapter" to
> the speaker in order to put the contacts of the speaker to the right spot.
> But there are some questions I have w.r.t. this:
> * Impedance: I measured 30 Ohms with my multimeter which is
>   promising, as it should be 32 Ohms, shouldn't it?
>   But do multimeters measure restistance using AC?

There is also some tolerance but it appears to be ok. Maybe not
in optimal HiFi quality :)

For the Case Kit we will also have a rectangular earpiece but its
contact points are not compatible with the GTA04A4 board. The A5
board will have additional contact points.

> * If I put it into place it will cover two contact-points
>   (see attachment "covered_contacts"). These are labeled "RFID+" and
>   "RFID-" in the manual (last page).
>   Is this a problem? What are those used for?

They are connected to the RFID-EEPROM and you could connect an
antenna to it to receive energy and signals. So they are input-only.
Shorting them should not really be a problem. But as was alredy
commented, you could isolate the pads.

> 
> 2. A vibra-motor (see attachment "shicoh...") labeled "SHICOH B7R2A". It
> fits almost perfectly into its place in the case, but the contacts are
> not at the right spot.
> I guess the original vibra-motor has its contacts at the very edge of
> one side, doesn't it? I am thinking about bending the contacts such that

Yes. Please see: http://www.handheld-linux.com/wiki.php?page=Neo%20Freerunner%3ASpare%20Parts

> they are at the right place...
> Do you think I can use this motor?
> What are the exact (mechanical or electral) specifications of a usable
> motor?

Unfortunately there aren't many specs.

I think there is an Asus spare parts shop in sweden still selling the
original replacement parts (they had been used in some Asus phone
as well).

And I remember that someone told me that the speaker of a Nokia 6610
is mechanically compatible (round shape + spring contacts). But its
Vibra motor is 1mm too long.

-- hns