How to buy used DJ equipment: what to check before you buy

Buying used DJ equipment can be a great way to get professional gear for considerably less than buying new.

But there is an important difference between checking that a unit switches on and checking that it actually works correctly.

At Sounds Market, we buy and inspect used DJ equipment all the time. As we explain in our guide to whether it is safe to buy used DJ equipment, more than 50% of the equipment we buy needs some form of work.

Often, these are small adjustments or repairs and, in many cases, the seller does not even know there is a problem.

That is why we have put together this guide based on our experience: what we would check before buying used DJ equipment.

Before you start: do not settle for a five-minute test

If you can test the equipment in person, take your time.

Switching it on, playing a track and checking that sound comes out is not enough. A CDJ, mixer or controller has dozens of different controls, connections and functions.

We also recommend always checking that the equipment still has its serial number, and asking the owner where it came from, how it has been used and whether it has been repaired before.

Then comes the most important part: testing the unit.

What you need to check varies considerably with the type of equipment.

How to check a used Pioneer CDJ-2000NXS2

We will use the Pioneer CDJ-2000NXS2 as an example, because it is one of the professional players we know and inspect most often.

Jog wheel

Turn the jog wheel and check that its movement is smooth and consistent.

Set the jog tension to LIGHT and give it a firm spin. Listen to the noise it makes as it turns.

Excessive noise may indicate that the bearings need maintenance or lubrication.

PLAY and CUE

Do not test these buttons just once.

Press PLAY and CUE repeatedly, trying different areas of each button.

We come across units where they appear to work but stop responding depending on exactly where you press.

Hot Cues and Loop

Check each of the four physical Hot Cue buttons individually.

Do the same with the loop controls.

Just because the previous owner did not use a particular function does not necessarily mean it works correctly.

Pitch

Move the pitch fader to the centre and check that it correctly registers 0.

Then slowly move the fader all the way up and down.

The value on the screen should change progressively. If you see unusual jumps in the value while moving the fader smoothly, there may be a problem with the control.

Buttons and encoder

Check every button individually.

Pay particular attention to frequently used controls such as TRACK SEARCH, SEARCH, SYNC and MASTER.

Also check the selection encoder: it should scroll correctly in both directions and respond when pressed.

Touchscreen

Do not test only the centre of the screen.

Touch different areas, particularly the edges and corners, to check that the entire touch surface responds correctly.

USB

Insert a USB drive, play some music and gently move the connected drive.

A connection that appears to work can lose contact with a slight movement.

LINK port

Connect an Ethernet cable to the LINK port and check both the connection and the socket itself.

The cable should lock securely into place when inserted.

RCA output

Connect the player via RCA and play audio.

While it is running, gently move the connectors to check for dropouts, noise or interference.

CD drive

Although many people no longer use CDs, the CDJ-2000NXS2 has a CD drive and it is part of the unit.

To check the whole player, insert a CD and confirm that it reads and plays correctly.

Quick CDJ-2000NXS2 checklist: jog wheel, PLAY/CUE, Hot Cues, loops, pitch, buttons, encoder, touchscreen, USB, LINK, RCA and CD drive.

How to check a used Technics SL-1200 / SL-1210

A Technics may seem much simpler than a CDJ, but it has its own critical areas.

Many units currently available have also been running for decades.

Pitch

This is one of the first things we would check.

The pitch fader should move correctly and the speed should respond consistently throughout its travel.

A platter turning is one thing; a correctly calibrated pitch control is another.

Tonearm

Inspect the tonearm carefully.

It should be straight, with no cracks or visible damage.

Also check for excessive mechanical play in its joints.

RCA

Connect the RCA cables and play audio through both channels.

Then gently move the cables near their connections.

We quite often see Technics turntables whose RCA connection seems fine in one position but produces noise, loses a channel or becomes intermittent when moved.

Ground wire

Also check the ground wire's condition and that it connects correctly.

Starting and stopping

Test START/STOP several times and check how the motor behaves when starting and stopping.

33 and 45 RPM

Check both buttons and make sure the turntable switches correctly between the two speeds.

These buttons can also suffer wear or damage after many years of use.

Quick Technics checklist: pitch and calibration, tonearm, RCA, ground wire, motor, START/STOP and 33/45 RPM buttons.

How to check a used Pioneer DJM-900NXS2

With a mixer, the number of things to check increases considerably.

We will use the Pioneer DJM-900NXS2 as our example.

Test every input

Do not connect a source to just one channel and consider the mixer checked.

Test the different channels and their LINE and PHONO inputs.

One input may have a problem while the rest of the mixer works perfectly.

Test every output

Do the same with the outputs.

Check MASTER via both XLR and RCA, and test the BOOTH output too.

Channel faders

Move each fader through its full travel several times.

The movement should be smooth, without sticking at any point.

Also check that the audio level responds correctly throughout its travel.

Crossfader

Move it fully in both directions and check that it cuts the audio correctly.

CUE

Check each channel's CUE button individually.

Do not press it only in the centre. Press it several times in different areas to detect possible contact problems.

Also check both the full-size and mini-jack headphone outputs, gently moving the connector as you listen for intermittent contact or interference.

EQ and Filter

Check LOW, MID and HIGH on every channel.

The rotary controls should move correctly, with an identifiable centre position.

Check that the EQ affects the signal correctly too.

Do the same with the filters.

Sound Color FX

Activate each Sound Color FX individually and check its buttons and operation.

Beat FX and LEVEL/DEPTH

Test the effects, paying particular attention to the LEVEL/DEPTH control.

Turn the knob while the effect is active and check that the signal remains stable, without dropouts when you touch or move it.

This is one of the controls that can see heavy use.

Quick DJM-900NXS2 checklist: LINE/PHONO, MASTER, BOOTH, faders, crossfader, CUE, headphones, EQ, filters, Sound Color FX, Beat FX and LEVEL/DEPTH.

How to check a used controller or all-in-one

Controllers and all-in-one systems combine many of the elements above.

We can use the Pioneer XDJ-RX2 as an example.

Jog wheels

Check both jog wheels individually.

They should turn correctly and behave similarly on both decks.

PLAY, CUE and playback controls

Test PLAY and CUE repeatedly on both sides, and check the loop and navigation controls too.

Performance Pads

The XDJ-RX2 has eight pads per deck.

Check all 16 individually.

It is easy to test two or three, see that they work and assume the rest are fine.

Pitch

Check both pitch faders from the centre position, slowly moving them through their full range.

The value should change progressively as you move the fader.

Touchscreen

Test the entire screen surface, not just the centre.

Mixer section

Many of the checks for a standalone mixer apply here too.

Check the channel faders, crossfader, CUE, EQ, filters and Sound Color FX.

Inputs and outputs

Check the available connections and the different audio outputs.

Also test both the full-size and mini-jack headphone connections, listening for dropouts or interference as you gently move the connector.

Quick XDJ-RX2 checklist: jog wheels, PLAY/CUE, pads, pitch, touchscreen, faders, crossfader, CUE, EQ, Sound Color FX, inputs, outputs and headphones.

What if you are buying online and cannot test the equipment?

The risk is greater here because you depend on the information the seller provides.

Ask for genuine, detailed photographs of the unit and make sure you can identify the model and serial number.

Ask specifically whether any button, input, output or function does not work correctly, and whether the unit has been repaired before.

You can also ask for videos demonstrating particular functions.

Do not just ask:

“Does everything work?”

It is much more useful to ask about specific parts.

“Do all the Hot Cues work?”

“Have you tested all the inputs and outputs?”

“Does the RCA connection make noise when you move the cable?”

“Do both headphone sockets work properly?”

The more specific the question, the more useful the answer.

What if you find a small fault?

Finding a problem does not necessarily mean you should rule out the purchase.

Professional DJ equipment may need maintenance or a relatively small repair and still have many years of life ahead of it.

What matters is knowing about the problem before buying and assessing how much it could cost to fix.

The trouble comes when you pay the price for a supposedly perfect unit and later discover that it needs a repair you had not budgeted for.

If you are unsure about a unit's condition, an inspection by a specialist repair service can help establish its true condition before you take on a major repair.

A quick test never replaces a full inspection

Everything covered in this guide consists of checks a buyer can carry out before purchasing used equipment.

In our workshop, we can go further.

When equipment goes through the Sounds Market refurbishment process, we use its Service Mode or diagnostic mode, where the model supports it, to check individual controls. We then carry out a real-world operational test, including inputs, outputs and extended running.

See the process in more detail in our guide to what refurbished DJ equipment means.