2100 no signal on suncellular

[ecko7i]

my 2100 have signal on both globe and smart sim networks. lately i tried suncellular sim but it doesnt have signal. i think theres no problem on the sim itself coz i inserted it to other phone and it read fullbar. tried manually locate networks in the 2100 with the suncellular sim in it but its results only found globe and smart. any advises or suggestions regarding this problem?

[sergo_zmeia]

This 3th card..which Ur 2100 have problems with..are U sure its a 900/1800MHz card...cause if its not U will never find network..
Regards!
sergo_zmeia