Motorola DP3400 not recognised

HELP
Recently purchased a handful of DP3400 radios - 2 are recognised by CPS2 and my programming cable and the other 2 simply say they arent recognised by CPS. SO i reverted back to CPSv15 and still no joy. So i presume these are such old FIRMWARE than even cps15 wont recognise.
Any ideas team ?