KONICA MINOLTA bizhub C360i junk prints

[~ITdude~]

I have a KONICA MINOLTA bizhub C360i and when a user prints to this printer it will print 400+ pages of junk. Doesn't matter what PC. Each PC is set up to printer direct to the printer over a network. Any recommendations on what I can do?

 

[PeterBJ]

Something similar has happened to me with an HP laser printer. When a print job was sent to it, it would print one line of random characters on a sheet of paper, then another line on a new sheet of paper and so on until the printer was turned off.

The cause of the problem was a corrupted printer driver. Uninstalling and reinstalling the printer solved the problem.

 

[~ITdude~]

I uninstalled the driver and reinstalled the latest driver and this didn't fix the problem. Anything else recommended?

 

[thebestcpu]

Hi @~ITdude~

In debugging, my usual first step is to determine what changed when the problem started. Usually a good indication. I am not experienced with your printer yet a lot of information online.

I think online information needs to be taken with a big grain of salt yet the results I found seem like it listed reasonable suspects. This list may give you some ideas to consider yet I can not vouch for the information. I hope it sparks some ideas for yor to pursue yet you could always wait for a better expert to respond with knowledge of that printer.

John Wheeler

Most Likely Causes (Ranked)​

1) Wrong / Corrupted Print Driver (very common)​

If even one machine sends malformed data (wrong PDL like PCL vs PS), the printer may interpret it as raw data → prints hundreds of pages of symbols.


Typical triggers:

• Mixing PCL and PostScript (PS) drivers
• Using a generic Windows driver
• Old / mismatched driver version

What to do

• Standardize on ONE driver type:
  • Prefer: Konica Minolta PCL6 (latest)
• Remove all existing drivers from PCs
• Reinstall fresh from Konica Minolta support site
• Make sure ALL users use the same driver

---

2) RAW Port Printing (Port 9100) sending bad data​

You said users print direct over network—likely using:

• Standard TCP/IP port (RAW 9100)

If bad data hits port 9100, the printer will happily print garbage.


Fix / Test

• Change printing to:
  • LPR protocol instead of RAW
  • Queue name: lp
• Or route through a print server (recommended)

---

3) Stuck / Corrupt Job in Printer Memory​

Sometimes one bad job gets stuck and keeps reprinting.


Fix

• On printer panel:
  • Cancel all jobs
• Then:
  • Power OFF
  • Wait 30–60 seconds
  • Power ON

If needed:

• Clear spool / job history from admin menu

---

4) Firmware Bug or Corruption​

These bizhub models can misbehave if firmware is outdated.


Fix

• Check firmware version
• Update to latest from Konica Minolta

---

5) One Device Sending Garbage (even if it seems random)​

Even though it “doesn’t matter what PC,” sometimes:

• One device sends a malformed job
• Printer keeps printing it repeatedly

How to confirm

• Check job log on printer:
  • Look for:
    • Same username?
    • Unknown job type?
• Temporarily:
  • Disconnect network cable
  • Reconnect and monitor

---

6) Wrong Print Language Setting on Printer​

Mismatch between printer setting and driver:

• Printer set to PS, driver sends PCL → garbage

Fix
On printer:

• Set Auto Detect or match driver exactly

---

7) Network Noise / Port Scan Garbage (less common)​

Rare, but:

• Network scanners or security tools hit port 9100
• Printer interprets it as print data

Fix

• Disable RAW 9100 printing
• Use:
  • LPR
  • or IPP
• Restrict printer via firewall if possible

---

Recommended “Clean Reset” Approach (Best Practice)​

If you want to fix this cleanly and permanently:

Step 1 — Reset Printer State​

• Cancel all jobs
• Power cycle

Step 2 — Standardize Driver​

• Pick ONE:
  • Konica Minolta PCL6 driver
• Remove all others from every PC

Step 3 — Change Protocol​

• Switch from:
  • RAW (9100)
    to:
  • LPR (queue: lp)

Step 4 — Optional but Ideal​

• Set up a Windows print server
  • All PCs print through it
  • Prevents rogue jobs

---

Quick Diagnostic Shortcut​

If you want to isolate the issue fast:

1. Turn printer OFF
2. Disconnect network
3. Turn printer ON
   • If it still prints junk → internal issue
4. Reconnect network
   • If junk starts → network/driver issue

---

Key Insight​

Since:

“Doesn’t matter what PC”

The problem is almost certainly one of these:

• Driver mismatch across machines
• RAW port (9100) accepting bad data
• Printer interpreting wrong print language