Turntable Help.......I know nothing about this

I have an old Technics brand turnable and receiver I found in my basement, that I have had for years.
I took the turntable in to have it checked out, and it works fine, but needed a cartridge. The shop put one in, tested it in the store and it sounded great. He told me it was low output and I would have to play the turntable up loud.
When I got it home, it plays, but you have to turn the receiver up full to get any volume and the sound certainly is no where near what a cd will play. Years ago I used the same turntable and receiver with no problem.
Went back to the store, the guy will not take back or replace the cartridge, and says "it should work".
Anybody have any ideas how to make this thing work? Thanks.

Which cartridge did you get?
Shure, Grado, Sumiko?

There are 2 basic types: Moving Coil and Moving Magnet.
MC cartridges are usually lower output than the MM, and require a separate phono amp or boost circuitry in the pre-amp to handle the lower output.

You're missing the pre-amp. The turntable days involved either an pre-amp between the turntable and amplifier, or an amplifier with a stage of in-line additional amplification. Today's amplifiers aren't likely designed to work with the low level output of turntable cartridges. It will require a pre-amp.

There's nothing wrong with your cartridge. The low output signal is normal.

What input are you plugging it into? It needs to be plugged into a "phono" input, which is commonly NOT found on modern receivers and stereo systems. It is a low level input with special equalization -- not the same at all as tape, aux and other inputs, which are known as "line" inputs.

You may need a phono preamp, which should be available at Radio Shack and other electronic stores.

Tom

EDIT: I see that Empath got here before me. What he said ...

Thanks everyone, out to get a pre-amp!