Small philips head screwdriver, knife and tweezers. Magnifying
glass. You need to have good soldering tools. I use these two bits
on my 25W soldering iron:
The normal bit is used for desoldering, and the fine bit
(actually a length of copper wire wound around a normal bit) is
used for soldering fine pitch components. If you need to desolder
quad ics (those with pins on all four sides) you might find a
heavier iron, of 50W, useful. A desoldering pump would be handy,
too, but see below:
Head over to the music shop, and buy some rosin. That's the
stuff violinists use to rub their bows with so that it makes
squeaky sounds when rubbed across stretched wires over a wooden
box. That is also the stuff inside rosin cored solder - what
looks like wire is actually hollow, with rosin inside it. This is
the best material I have found for fluxing electronic solder
joints, and you can reuse solder if you have it. Otherwise you
will have to melt yards of solder wire just for the effect of the
rosin inside, and wipe away the resulting pools of solder. It is
a solid, and will have to be melted for application. My favourite
method is to heat the wire to be soldered and dip it into the
rosin for a thin coating (Pull it out fast before the rosin
The best method of clearing away excess solder is to absorb it
inside a desoldering wick. This is a length of copper braid
saturated with flux. You can make it by taking a length of fine
braid from a shielded cable and melting some rosin into it.
This is the capacity of my mp3 player before upgrading - 119
Mbytes. The replacement chip is a 4 Gbit Samsung Nand Flash chip,
supplied to me by a member of this forum.
The two chips are shown, side by side, below. The original is
by Hynix, and the replacement is by Samsung. They both are
compatible with the s1 mp3 player.
The first step is to get two lengths of straight copper wire,
just long enough to cover the side of the chip with pins. The cut
off leads from components will do. The cut off lead from a 1N4007
or similiar 1 amp diode is ideal. If the wire is not truly
straight, you can make it so by rolling it on the flat table top
between another flat surface, like a ruler.
Tin the wire by applying rosin and solder to it, and place
against the side of the chip and solder into place as shown
below. This is to enable us to heat all the pins on that side, at
the same time, equally.
Inspect your work and ensure that each pin makes secure
contact with the wire, and has a soldered connection to it. This
is important because you will be applying force to the chip to
remove it and a cold pin will remain stuck to the board, causing
the track to peel away from the board. When you are sure all
twentyfour pins are solidly soldered to your wire take another
one and solder to the other side, as in the photo above.
Then you take a flat, thin, springy piece of metal (I used a
piece of razor blade) to lever away the chip from the board, and
apply the hot iron to the wire at roughly the middle of the leads
of the chip. The chip will snap away from the board as all pins
reach the melting pint of solder. Now take the detached side of
the chip, and, pulling lightly, apply the iron to the other side.
The chip will come away in your hand, and if you have done it
correctly the two wires will be still attached to it. Leave them
in place, if you are not using the chip immediately, they will
help the chip survive damage from static electricity.
With the NAND flash off the board, I plugged the player into
the computer. I was rewarded with it being recognized as an ADFU
device. I tried to load a firmware file, and the computer
informed me that the flash was not responding, which was normal,
since the flash chips were now lying on the table.
I then positioned the replacement chip, aligning the dot on
the pcb with the circle on the package top left corner. One
corner pin was first soldered into position, using the tiny bit
on the soldering iron. No excess solder needed to be added for
this, since the board already had some tin on it and the chip's
leads also were tinned. The diagonally opposite lead was then
carefully positioned and soldered, so that the rest of the leads
lined up with their pads. Then it was just a case of pressing the
chip down and touching each lead in turn with the hot tip of the
soldering iron in order to make the joints fast.
The result will look like this: but with the chips
After the chip was soldered in, it was time for a quick check.
It was plugged into the computer, which recognized it as a
removable disk drive. Putting a battery into it resulted in a
green backlight, but with no functions. Loading the original dump
file and formatting it resulted in a fully functional device with
an available capacity of 497 Megabytes.
As the photo above shows, my player has been upgraded to half
gig capacity. I loaded it full with mp3 files and played random
selections. All the files I tried played back with no errors.
And this is the capacity of my player after upgrading and
formatting the memory. It is 99% full because I loaded it with
all the files it could take in order to test the integrity of the
memory. I read back some tracks at random and they all played