Top 10 POS Machine Problems and How to Fix Them

Last Updated: October 2025
Disclaimer: nigeriaussdcodes.com is an independent information website. We are not affiliated with any POS company or bank. This article is for educational purposes only. Always confirm official troubleshooting steps from your provider.

When Your POS Stops Working

In 2025, millions of Nigerians depend on POS terminals daily. Whether you are a roadside vendor, small-shop owner, or registered Moniepoint or Opay agent, your POS is your mini-bank.

However, nothing frustrates an agent like a failed transaction, network error, or “declined but debited” alert. These problems cost money, time, and customer trust.

This detailed guide explains the 10 most common POS problems in Nigeria and how to fix them quickly — no panic, no loss.

10 Most Common POS Problems in Nigeria and How To Fix Them

Network Connection Error (No Service or Transaction Timeout)

Cause:

• Weak 3G/4G coverage.

• Wrong APN configuration.

• SIM card not properly inserted.

Fix:

1. Restart the POS.

2. Check signal strength — switch location or provider SIM.

3. Re-insert SIM and confirm data plan.

4. If Android POS → open “Settings → Network → APN” and set to correct provider (e.g., mtnng, gloflat).

5. Retry after 2–5 minutes.

Prevention Tip:
Keep a dual-SIM device with at least two networks. Many successful agents use MTN + Airtel combo to stay online during outages.

Transaction Declined — Issuer or Switch Inoperative”

Meaning: the transaction reached the bank but the inter-switch network failed midway.

Fix:

• Wait 10–15 minutes and check the customer’s bank app.

• If debited, do not re-attempt.

• Take the transaction reference ID and contact your aggregator (Opay, Moniepoint, PalmPay).

• Provide screenshot and card last 4 digits.

Most Reversals: occur automatically within 24 hours on working days.

POS Printer Not Working or Faint Receipts

Cause:

• Paper roll inserted wrongly.

• Expired or damp thermal paper.

• Printer head dirty.

Fix:

1. Open printer cover → remove roll.

2. Re-insert paper with shiny side facing print head.

3. Clean head gently using dry cotton.

4. Replace roll if paper looks brownish.

Pro-Tip: Always store paper in a cool dry place; humidity ruins thermal quality.

POS Battery Not Charging

Possible Reasons:

• Damaged adapter.

• Loose charging port.

• Software glitch from continuous use.

Fix:

1. Try another charger (same voltage).

2. Clean port gently with dry brush.

3. Power off fully before charging.

4. If still dead, long-press power + volume-up for 20 seconds (for Android POS reset).

Maintenance Tip: Avoid charging with generator surge; use surge protector.

“Invalid Card / Unsupported Card” Error

Why It Happens:

• Card type not supported by POS (e.g., foreign Visa).

• Card chip worn out.

• Magnetic reader dirty.

Solution:

• Ask customer to try another card or use transfer.

• Clean card slot with microfiber cloth.

• Update POS software (Settings → Device Update).

Failed but Debited Transactions (Customer Money Missing)

This is every agent’s nightmare.

Steps to Resolve:

1. Write down RRN (Reference Number) on receipt.

2. Confirm transaction time and card digits.

3. Call your aggregator support or send email with RRN.

4. Tell customer reversal may take 24–72 hours.

5. Record details in your transaction log.

If no reversal after 3 days:
Customer should visit their bank with the RRN for manual reversal through NIBSS Dispute Portal.

Pro-Tip: Always print failed-transaction receipt for proof.

POS Terminal Freezes or Reboots Mid-Transaction

Cause: memory overload or outdated software.

Fix:

1. Close all apps → clear cache.

2. Restart device.

3. Check for system update.

4. Avoid multiple pending prints; clear history weekly.

Preventive Step: Do not run social media apps on POS — they slow performance.

“Invalid Merchant ID / TID” Error

Meaning: your terminal has not been activated or your settlement account is suspended.

Fix:

• Contact provider’s support (send your TID + serial number).

• Ensure KYC documents are complete.

• Avoid changing SIM without notifying provider.

Reversal Not Settling to Merchant Account

Cause: aggregator network delay or wrong settlement account.

Fix:

• Log in to dashboard → confirm account details.

• Send unresolved RRN to support.

• Reversal usually reflects within 48 hours once logged.

“POS Not Dispensing / Cannot Connect to Host”

Common with ATM-linked terminals.

Fix:

1. Restart device.

2. Check SIM data.

3. If multiple attempts fail → perform host reset:

   • Settings → System → Host → Reinitialize.

4. Contact network admin if persisted.

Extra Troubles You May Encounter

Daily Maintenance Checklist

Wipe device with dry cloth.
Avoid dropping or bending card slot.
Keep SIM data active.
Backup transactions every evening.
Turn off POS when not in use.
Update firmware weekly.

Real-Life Case Studies

Case 1 – Lagos Agent: Device kept freezing. Solution — cleared cache and updated firmware; worked perfectly.
Case 2 – Abuja Trader: Customer debited ₦15 000 twice. Merchant provided RRN; refund processed within 48 hours.
Case 3 – Ibadan Shop: “No service” daily 2–4 pm; discovered wall interference. Moved POS 3 meters — problem solved.

How to Contact POS Support

Always provide:

• Date & time of transaction

• Amount & card digits (last 4 only)

• RRN/reference number

• Your merchant name/TID

Preventive Habits for Long-Term Success

1. Network Discipline — monitor SIM balance daily.

2. Power Discipline — use small UPS to prevent data corruption.

3. Record Keeping — maintain a notebook for failed transactions.

4. Customer Transparency — always reassure clients politely.

5. Training — attend periodic fintech agent workshops.

Frequently Asked Questions (FAQs)

Q1: What is RRN?
The Retrieval Reference Number used by banks to trace a POS transaction.

Q2: Can failed transactions be reversed on weekends?
Yes, if the bank’s NIBSS portal is active; otherwise by next working day.

Q3: My printer stopped mid-receipt — should I redo the transaction?
No. Wait to confirm debit status first.

Q4: How do I avoid fake reversal claims?
Verify reversal SMS with your dashboard balance before refunding.

Q5: Is it safe to use public Wi-Fi for POS?
No. Use only private mobile data connections.

Summary Table — Top 10 Problems & Quick Fixes

Conclusion

POS work demands patience. Most issues are temporary and fixable with simple steps — restart, verify network, reinsert paper, or report RRN.

Your professionalism during a fault can determine whether customers stay loyal or leave. Keep your device updated, maintain steady power, and never rush to repeat failed transactions.

A reliable agent doesn’t avoid problems — they know how to fix them fast.