hello mr wazoo,try jiggling it about and maybe push the lead towards the plug, sometimes a bit of jiggery pokery can do the trick.if there is no problem with the headphones there shouldn't be one with the adaptor and they can be a tight fit,if that fails take it back to maplins,i know they are not dear but it's your money.sennheiser are good for adaptors.hope this helps,gregory.