If replacing the toner cartridge doesn’t resolve light print problems, check the rollers.


On a recent service call, my customer complained to me that their HP LaserJet P4014 was having some print quality issues. When I printed a test page I noticed that there were several areas down the left side of the page that had light print. My first thought was to replace the toner cartridge but the customer informed me that they had already done so but the problem had been on-going.

Since the light print was not consistent down the page, but happened at intervals, I knew right away I could rule out the laser scanner assembly as the problem. After running a half test and confirming that the defect was on the page before the image was fused, I knew it was either the transfer roller or toner cartridge. Continue reading

Leaking Cartridge Causing Black Prints


More often than not, toner leaks aren’t a serious problem—you simply remove the toner cartridge that is leaking, carefully clean out the print cavity, and the machine is back in business. In a worse-case scenario you may need to vacuum out the print cavity. Sometimes, however, it’s not this simple.

Case in point
On a recent service call regarding a leaking toner, the leak actually led to paper jamming under the toner cartridge. The customer had already replaced the toner cartridge but, unfortunately, the machine was now printing all black pages. I immediately put the old cartridge (that was leaking) back into the printer but continued to get black pages. With both the old, leaking cartridge and the new replacement cartridge, I could faintly see that a print image was on the page. And an engine test produced the same result―black page with faint horizontal lines. Continue reading

Troubleshooting “black pages” caused by a toner leak


More often than not, toner leaks aren’t a serious problem.  When you simply remove the toner cartridge that is leaking and carefully clean out the print cavity, the machine is back in business. In a worse case scenario, you may need to vacuum out the print cavity to clean up larger messes.

Sometimes, however, it’s not this simple.

Case in point
On a recent service call for a leaking toner, the leak actually led to paper jamming under the toner cartridge. Continue reading

HP LaserJet 10.00.00 Supply Error


This error happens most often when a customer installs a new toner cartridge (the error suddenly appears on the display), but can also occur after the cartridge has been in the machine for a while or when the wrong cartridge is installed in the printer.

This 10.00.00 supply error is more often than not related to the chip on the toner cartridge but can also be caused by the reader inside the machine. Personally, I’ve never seen this error occur when using an HP OEM cartridge, I have only seen it when a customer is using a rebuilt or third-party cartridge.

In the HP 4200 and 4250 series the 38 and 42 cartridges can go into either machine. While they are hard to get in and out if interchanged, it can be done. When customers have multiple units of each printer in their business, they occasionally install the wrong cartridge, Continue reading

Loss of power in an HP M4555 MFP


A few days ago I was called out to work on a HP M4555 MFP machine that didn’t have any power—no lights on the control panel or formatter board, no fans, no anything. The call was through a National Service Provider (NSP) so a customer service technician had diagnosed the machine over the phone and a low voltage power supply (LVPS) was sent to the customer’s office to be replaced.

When I arrived onsite I tried a few quick troubleshooting steps and decided to go ahead and take a look at the LVPS and noticed that one of the two fuses on it had blown. Since the NSP had sent out a replacement power supply, and I already had this one out, I decided to install the new LVPS.

Typically, when you have a blown fuse, simply replacing the fuse or the board fixes the problem. Unfortunately, once I replaced the LVPS, put the machine back together, and turned it on I heard a loud popping noise and the nice smell of electrical components burning.   Continue reading

Firmware Update Issues? Check the Formatter Port


A few months ago I went out to a customer site to update firmware on five HP P4015 machines. They had been having unexpected print problems after upgrading their computer systems to Windows 8. Unfortunately this seemingly simple job went south quickly. Let me explain.

I downloaded the firmware on the first machine and it crashed half-way through the update. I rebooted the machine and was confronted with a SEND RFU UPDATE message. I was able to get the machine to a ready state and print some test pages but the network port was no longer working so I had to go to the USB update. Again, the firmware update crashed half-way through. Continue reading

Toner Specks Running Down the Page Vertically


Toner-Speck-on-paperA common problem that I run into with HP Color LaserJet 3500, 3550, 3700 printers is toner specks running down the paper vertically. This problem is different than periodic dots that show up on the page at defined intervals, otherwise known as repetitive defects. With a repetitive defect, note the color of the dot and measure the distance between the dots. The service manual describes what internal roller is causing the problem and you can simply replace the appropriate part.

Random toner specks can be a little more difficult to diagnose. Continue reading