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Guitar Pedal Not Working? Check These in Order (No Light, No Sound, Cuts Out)

I'm Andrew. A pedal that won't light up, or goes silent when you switch it on, is usually a power or cable problem, not a broken pedal. Work through the checks below in order. Most of them are free.

Which page do you need? Pedal works but hums or whines? Whole rig silent even without pedals? See guitar not making sound when plugged in.

Quick answer

Check that the adapter matches the voltage and polarity printed on the pedal (most are 9V DC, center negative), that the cables go into the right jacks (guitar into IN, OUT to the amp), and test the pedal alone with a known-good cable. If it still won't work alone with the right power, it's a repair job.

See all care & repair guides

Safety first

No light: power checks

  1. Voltage. Read the label near the power jack. Most pedals take 9V DC. Some take 12V or 18V, and some take 9V only. Never go higher than the label says.
  2. Polarity. Most pedals use a center-negative barrel plug, shown by a small symbol by the jack. A center-positive adapter can stop the pedal working or damage it.
  3. Current (mA). The adapter or supply output must give at least the current the pedal needs. Digital pedals often need far more than older analog ones. Too little current can cause odd behavior or no power at all (Roland support says under-powered pedals can malfunction).
  4. Daisy chains. If one adapter feeds several pedals through a chain cable, unplug the others and test this pedal alone.
  5. Battery. Many battery-powered pedals only turn on when a cable is plugged into the INPUT jack. Try a fresh 9V battery, or take the battery out while testing an adapter.
  6. Loose plug. If the light flickers when you move the power plug, the plug or jack is loose. Red Panda's support notes this as a common cause of power cutting out.

Light on, but no sound

  1. IN and OUT swapped. On most pedals the input is on the right and the output on the left, but check the labels.
  2. The pedal alone. Guitar into the pedal, pedal into the amp, with two cables you know work. If it works alone, the problem is elsewhere in the chain.
  3. Patch cables. Short patch cables fail too. Swap each one.
  4. Mono vs stereo cable. Most pedals need a plain mono (TS) instrument cable. A stereo (TRS) cable in the wrong jack can cause silence or odd results. Check the manual.
  5. Settings. A volume or level knob at zero, or a blend or mix knob set fully dry, can make the pedal seem dead.
  6. Sound only when the pedal is off? That points to a fault in the effect circuit or footswitch, after you've ruled out power. It's time for the maker's support or a repair tech.

When to stop

If the pedal is still dead alone, with the right adapter and good cables, stop there. Contact the maker if it's under warranty, or a repair tech if it isn't. Footswitch and jack replacements need soldering, and a bad repair can void the warranty.

Gear that helps you test

The free checks above fix most dead pedals. If you need a known-good adapter, a better supply for several pedals, or replacement cables, these match the problems above. Check your pedal's voltage, polarity and current before you buy any power supply.

Boss PSA-120S Power Adapter

Best for A known-good test adapter for a single standard 9V pedal: Red Panda names it as its go-to

9V DC, center negative, 500 mA (per Boss/Roland)Fits standard Boss-style barrel jacks

Specs: Boss product page and Roland support, checked 2026-11-02.

Check today's price on Amazon (Amazon affiliate link: as an Amazon Associate, FretCompare earns from qualifying purchases.)

Truetone 1 SPOT Pro CS7 Isolated Power Supply

Best for A board with several pedals, including digital ones that need more current

7 isolated outputs: 9V, 9V/12V, 18VCables included (per Truetone)

Specs: Truetone listing details, checked 2026-11-02.

Check today's price on Amazon (Amazon affiliate link: as an Amazon Associate, FretCompare earns from qualifying purchases.)

Ernie Ball Flat Ribbon Patch Cables, 6in, 3-pack (P06221)

Best for Replacing a suspect patch cable between pedals

6-inch, 1/4-inch TS plugsLimited lifetime warranty (per Ernie Ball)

Specs: Ernie Ball product page (P06221), checked 2026-11-02.

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Ernie Ball Flex Instrument Cable, 10ft

Best for A known-good guitar cable for the swap test

10 ft straight-to-straightFlexible jacket (per Ernie Ball)

Specs: Ernie Ball product page, checked 2026-11-02.

Check today's price on Amazon (Amazon affiliate link: as an Amazon Associate, FretCompare earns from qualifying purchases.)

Product links checked 2026-11-02 against each exact Amazon listing; Amazon shows the current price. See How we rate.

Sources checked Nov 2, 2026: Roland/Boss support (PSA adaptor specs, powering multiple pedals); Red Panda support (power supply and power cutting out); Ernie Ball and Truetone product pages.

FAQ

Why is my guitar pedal not turning on?

Usually it's the power: the wrong voltage or polarity, an adapter that can't supply enough current, a dead battery, or a loose plug. Many battery pedals also need a cable in the INPUT jack before they switch on.

Why does my pedal kill my signal when I turn it on?

Check the cables (IN and OUT, patch cables), the pedal's level knob and its power. If it still cuts out alone with the right power and good cables, the pedal needs repair.

Can the wrong power supply damage a pedal?

Yes. Too high a voltage or reversed polarity can damage a pedal. Always match the label on the pedal or its manual.

Is it safe to open my pedal's power adapter?

No. Never open a wall adapter or power supply: it connects to mains power. Replace a damaged adapter.

Why does my pedal work with a battery but not the adapter?

The adapter may have the wrong polarity or voltage, be too weak for the pedal, or be faulty. Test with a known-good adapter that matches the pedal's label.

Related: Pedal power supply noise - Guitar not making sound when plugged in - Crackling guitar jack - First guitar pedal - Pedals guide - Cables

How this page was made: Andrew wrote this guide from makers' manuals, support pages and product pages, listed above. Each button opens the exact Amazon listing (checked 2026-11-02), and Amazon shows the current price. How we rate

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