26
HP Printer
Severity: ModerateWhat Does This Error Mean?
Error 26 on an HP printer means the printer cannot read a memory cartridge or DIMM module. This memory is used to store fonts, print job data, and printer settings. The fix usually involves reseating or replacing the memory module.
Affected Models
- HP LaserJet 4
- HP LaserJet 4 Plus
- HP LaserJet 5
- HP LaserJet 4000 Series
- HP LaserJet 4050 Series
Common Causes
- The DIMM memory module is not fully seated in its slot
- Dust or debris on the DIMM module's gold contacts is blocking the connection
- The memory module is defective or has failed
- An incompatible memory module was installed (wrong speed or capacity)
- Static electricity damaged the memory module during installation
How to Fix It
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Turn off the printer and unplug it from power. Wait 30 seconds before opening any panels.
Always discharge static electricity by touching a metal surface before handling memory modules.
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Open the printer's side or rear access panel to locate the DIMM memory slots.
Your printer manual will show the exact location — it is usually a small green circuit board in a long slot.
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Press the locking clips on both ends of the DIMM slot outward to release the module. Remove it carefully.
Hold the DIMM by its edges only. Do not touch the gold contact strips along the bottom edge.
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Inspect the gold contacts on the module for dirt or corrosion. Gently clean with a dry eraser if needed, then reinsert firmly.
The DIMM clicks into place when fully seated — you will feel and hear both clips snap back.
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Plug in and power on the printer. If error 26 persists, try removing the DIMM entirely to see if the printer works with base memory.
If the printer works without the DIMM, the module itself is faulty and needs replacement.
When to Call a Professional
If reseating or replacing the DIMM module does not resolve error 26, the memory slot on the printer's formatter board may be damaged. This typically requires a full formatter board replacement. A repair technician can test and quote the cost — usually $100 to $200 for the part and labor.
Frequently Asked Questions
Do I need the DIMM module for my printer to work?
It depends on your printer model and how much memory it has built in. Many older HP LaserJets come with base memory soldered to the board. The DIMM is typically an upgrade — removing it may reduce the printer's ability to handle complex or large print jobs.
How do I know if my DIMM module is compatible with my HP printer?
HP's support website lists approved memory upgrades for each printer model. Using incompatible memory — wrong speed, wrong capacity, or wrong form factor — will cause errors like error 26. Always match the specifications exactly.
Can error 26 cause data loss?
Not typically. Error 26 prevents the printer from operating, but it does not delete files from your computer. Any print jobs waiting to be sent will still be on your computer's print queue. Once the memory issue is fixed, you can resend them normally.