I have just seen a picture of the Iriver PCB. As predicted, there are 6.3V Tantalum caps. Most black, but a few orange also. The voltage is printed on the caps. The other number specifies the capacitance. Example: 226. This means: 22 plus 6 zeros, 22.000.000pF = 22uF. The first two figures are text, the third number specifies the number of zeros, giving the cap value in pF. 1000.000 pF = 1 uF.
Or, on the picture: 107. That means 10 - 0000000 = 100.000.000pF = 100uF. Before removing caps, check with an Ohmmeter if they are shorted. Some of the caps are output/input coupling caps, they won't be damaged by too high a charger voltage, and therefor the Ohmmeter will not read 0.0. Replace only those caps that are shorted.
