Credit Card Machine Not Working – Common Issues and Fixes

Updated October 2025

Quick Answers: Common Fixes for a Credit Card Machine That’s Not Working

• Machine not connecting? Restart your POS, router, and modem. Ensure Wi-Fi or Ethernet cables are secure, and update terminal firmware.

• Card not reading? Clean the chip reader with an approved card cleaner, check for worn chips or swipe damage, and retry using contactless or manual entry.

• Transaction declined? Confirm a strong connection, retry once, and have the customer call their issuer if the issue continues.

• Frozen or unresponsive screen? Power-cycle the terminal, disconnect from power for 30 seconds, then reconnect.

• Slow or offline payments? Check for software updates and weak network signals. Move the device closer to your router or remove interference.

Why Credit Card Readers Matter

Credit card readers—also called terminals or POS devices—are the backbone of modern commerce. Smooth and secure transactions keep sales flowing, build customer confidence, and encourage repeat business. When your credit card machine stops working, transactions stall, customers get frustrated, and revenue is lost.

This updated guide covers the most common reasons card machines fail and provides practical fixes to get your terminal back online. You’ll also find proactive maintenance tips and best practices for keeping downtime to a minimum.

How Your Credit Card Reader Works

A payment terminal reads the card’s chip or magnetic stripe, encrypts payment information, and securely transmits it over the network for authorization. Many modern terminals also accept NFC (contactless) and mobile wallet payments, such as Apple Pay and Google Pay. Knowing how your device connects, processes, and updates helps you troubleshoot faster and operate more efficiently.

Types of Credit Card Machines

Today’s businesses can choose from a range of reader types:

• Countertop machines offer the most stable connections and are ideal for fixed checkout counters.

• Portable readers connect via Wi-Fi or Bluetooth and work well for restaurants and service businesses.

• Mobile readers pair with smartphones or tablets, perfect for contractors, delivery services, and mobile vendors.

Many businesses combine device types for flexibility—such as a countertop terminal in-store and a mobile reader for off-site sales.

Common Issues and Quick Fixes

Card machines can develop glitches for several reasons—network interruptions, outdated firmware, power surges, or even environmental factors like dust.

The most frequent problems include:

• Connectivity issues

• Card declines or read errors

• Firmware or software glitches

• Printing errors and paper jams

• Power or overheating problems

Following the troubleshooting steps below can resolve most issues before you need to call support.

Connectivity Issues and Fixes

1. Check your network: Verify Wi-Fi or Ethernet connectivity. Switching to a backup hotspot or wired connection often restores service.

2. Restart and reset: Reboot your machine, router, and modem in that order. This clears temporary network errors.

3. Verify settings: Incorrect IP or DNS details can prevent authorization—ensure network configurations are current.

4. Update firmware: Many connectivity failures trace back to outdated software. Run updates via your admin portal or contact your provider for help.

5. Reduce interference: Nearby motors, LTE routers, or metal barriers can disrupt wireless signals. Relocate if necessary.

Declined Transactions and Error Messages

A “declined” message does not always mean customer funds are unavailable. Common causes include weak connectivity, outdated encryption keys, or issuer-level restrictions.

• Retry once only after verifying connectivity.

• Confirm with the cardholder’s issuer for regional or limit restrictions.

• Avoid multiple retries, which could lead to duplicate charges.

• For recurring declines, try another card or payment method, such as ACH or contactless.

Adding a short user-facing FAQ like “Why is my card declined?” can reduce staff frustration and improve customer understanding.

Resetting and Rebooting

A simple reboot can often solve lag, display errors, or unresponsiveness. Disconnect the power or battery, wait 30 seconds, and restart. If problems persist, perform a factory reset—but only after consulting your payment provider, as this will erase stored configurations.

Software and Firmware Updates

Regular system updates are essential for reliability and PCI DSS 4.0 compliance. Updates patch vulnerabilities, improves performance, and supports new payment methods. Many cloud-connected terminals now update automatically; others require manual action through your provider portal or connected POS system.

Cleaning, Maintenance, and Device Longevity

Dust, debris, or worn sensors can cause card and NFC read failures.

• Clean using only approved cleaning cards or wipes designed for terminals.

• Never use general cleaners or alcohol-based products on contact surfaces.

• Replace printer rolls with manufacturer-approved thermal paper types.

• Review internal logs quarterly to track performance and identify irregularities.

Modern terminals typically last 5–7 years, depending on usage volume, software support, and evolving security standards—not the older 10-year assumption.

IntelliPay Supported Credit Card Terminals and Specific Guidance

Verifone V200 & V400 Series

These devices are among the most common and reliable payment terminals.
If your Verifone V200 or V400 terminal isn’t working properly, try the following quick fixes:

• Restart the device: Hold the green Enter button for 8 seconds, or unplug and reconnect power.

• Check all cable connections: Loose power or Ethernet cords often cause “No Connection” or “Tamper” errors.

• Run a network test: From Settings → Diagnostics → Network, verify IP and DNS configurations. If necessary, restart the network interface (LAN/Wi-Fi).

• Update software: Confirm the firmware is up to date to maintain PCI DSS 4.0 compliance and ensure support for contactless payments.

• Avoid disassembly: Verifone V200 and V400 terminals use tamper-evident housings—opening or modifying the device may void the warranty.

Common symptoms: blank screens, keypad not responding, failed transactions, or repeated “Declined” messages. If these persist after a reboot and software update, contact IntelliPay Technical Support for next-step verification or hardware swap recommendations.

Dejavoo P1 Android Terminal

The Dejavoo P1 is a high-performance, Android-based countertop terminal. While user-friendly, network and performance issues can arise occasionally.

Troubleshooting tips include:

• Network connection: Ensure a strong Wi-Fi or 4G signal. Re-enter the Wi-Fi password if connections fail.

• Slow performance or freeze: Perform a hard restart by holding the power button until the device turns off; then power back on.

• Payment issues: Make sure the P1’s payment app and firmware are updated to the latest version for smooth EMV and contactless processing.

• Unresponsive or frozen screen: Conduct a factory reset only if absolutely necessary, and back up your data first.

• Printer problems: Check for jammed or misaligned thermal rolls and refill as needed; restart the printer module afterward.

These fixes resolve nearly all standard issues with Dejavoo devices. Persistent problems may indicate a hardware fault or misconfiguration, in which case contacting IntelliPay’s support team will ensure rapid resolution.

Advanced Troubleshooting

• Power issues: Always use a surge protector; unstable current can cause failure or data loss.

• Overheating: Avoid storage in enclosed or hot environments; allow airflow around vents.

• Printer problems: Check paper alignment and clear jams before restarting.

• Chip reading errors: Clean readers monthly or recalibrate sensors if available.

• Manual entries: Use only as a last resort due to higher interchange fees and chargeback risk. Always confirm data before submission.

Compliance and Modern Payment Trends

With the implementation of PCI DSS 4.0, merchants must verify device tamper seals, maintain encryption key integrity, and restrict manual entry where possible. If your terminal doesn’t support EMV or NFC, consider upgrading to ensure compliance and enhance customer convenience.

Businesses also adopting dual pricing or surcharging programs should confirm that device configurations reflect compliant fee displays and accurate receipt presentation.

When to Contact Support

Call for professional help if:

• The device fails to connect after standard troubleshooting.

• Continuous declines or error codes persist.

• Water, heat, or surge damage is suspected.

• Buttons, chip slots, or keypads fail mechanically.

Regular Audits and Performance Checks

Perform regular audits every few months to test card acceptance, verify log reports, and confirm transaction speeds. Auditing helps catch slow degradation before it disrupts checkout experiences.

Life Expectancy and When to Upgrade

Replace your terminal if:

• It no longer supports contactless or EMV transactions.

• The manufacturer ends support or firmware updates.

• The device runs slowly or frequently freezes.

• Newer models offer better connectivity, payment types, or hardware durability.

About IntelliPay

At IntelliPay, we help businesses simplify payments with transparent pricing, modern technology, and expert customer support. Whether you need help troubleshooting a terminal or upgrading your payment systems, our specialists ensure fast, secure, and compliant payment processing that keeps your business moving.

Reviewed and updated October 2025