Sure sounds like the accumulator is not working. This means it is full of water or the membrane is punctured. If your accumulator has a Schrader valve, then try this: switch off the power to the pump and open any faucet. Allow water to stop flowing and leave faucet open. Connect a 12 volt air pump with pressure gauge to the valve and switch it on. Some water will flow from faucet. If reading on pressure gauge increases and HOLDS when air pump is turned off then you have recharged the accumulator. If it drops down to zero, the diaphragm is toast.
BTW: in my experience the little black plastic accumulators DO have a diaphragm inside. The above procedure works with them too.
If all else fails, read the instructions
If it ain't broke, don't fix it