HP LaserJet 5SI
Who can help resolve toner failure shown in this picture:

Experienced technical support provide their insights in answering this question :
Why not just replace the toner cartridge?

How to Identify and Fix Common printer Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced technical support :

Most printers will stop working when they`re out of paper, ink or toner, or if the unit detects an issue with the ink or toner cartridge. When this occurs, you might receive an error message or notice blinking green or amber lights on your printer.
A Cartridge is Low or Cartridge is Very Low message displays when the amount of toner in the cartridge is below a certain percentage. This message is a reminder to have a replacement toner cartridge available. You do not need to replace the toner cartridge until print quality becomes unacceptable.
The printer is either low in toner, the density is set too low, or the Economode may be turned on. Remove the toner cartridge and shake it. This will redistribute the toner and often will temporarily solve the problem. However, this usually indicates it is time to install a new cartridge.
There`s a chance that the printhead hasn`t been installed properly or has been clogged with dried ink or debris. If this is the case, then cleaning your printhead may resolve the HP ink system error.
Many printer models won`t print if there`s a loose USB connection or if they`re out of ink or paper. Verify your printer`s ink levels, clean the printhead, fill the paper tray, and avoid using substandard paper.
“Toner Error” will appear on your machine`s display if one or more toner cartridges are not installed or not installed correctly.
As a general rule, when a printer runs out of ink or toner, it stops printing legibly. Depending on the printer model, the unit may look to replace one colour with another. For example, if you run out of black ink, your printer could replace it with blue, in order to still print the document you need.
“Toner Low” indicates that the toner cartridge is approaching the end of its expected life, but the cartridge has not yet reached its end of life. It`s recommended that the toner cartridge continue to be used if the print quality is still good.
A typical toner cartridge will produce anywhere between 2,500 and 4,000 pages, based on a coverage of 5% (roughly third of a page of double-spaced text). Dense pages filled with small font text or graphics will dramatically reduce this output and you may only get up to 1,000 pages per cartridge.
1. Paper Jams. Paper jams are perhaps the most loathsome of all printer problems. While your knee-jerk reaction may be to rip the paper out in both frustration and an attempt to clear the block, we recommend some patience.
Empty ink or toner cartridges that need replacing. Ink or toner cartridges that have become dislodged from their proper place. The wrong paper size loaded in the input tray. Clogged printer head nozzles causing a build-up of blocked ink or toner.
A mistake in anything that`s printed is a misprint. You might also call it a typographical error or typo.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Expired Toner and Suggestions for Source of Toner
ANSWER : Hi Frank, I had a very similar question two weeks ago, but my “old beloved workhorse” is an HP Laserjet 4L. From the good old days! I too had made bad investments in “new but old truly HP” toner cartridges, hoping to coax more life from my printer. I ended up choosing to try a remanufactured cartridge from www.4inkjets.com. It was a gamble, but the website said they had a 100% satisfaction guarantee. And I can tell you they have lighting fast service. I’ve now printed 50 pages without a flaw. JOY! While the cartridges and technology are different, I suggest you try the same place. And good luck!

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HP LaserJet 5SI

Toner failure
ANSWER : Why not just replace the toner cartridge?

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HP LaserJet 5SI

Brother toner cartridge low toner override
ANSWER : Thank you. You are a genius. Of course this is not a substitute for cartridge replacement but it is great for extending the life of the color cartridges and allowing you to continue to print until you can get new cartridges.

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HP LaserJet 5SI

Brother toner cartridge low toner override
ANSWER : follow these steps:

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HP LaserJet 5SI

toner cartrigdes and drums
ANSWER : You can, but there are good knock-offs and bad ones. I’ve run into ones that come totally empty. Ones that don’t have the chips installed that identify themselves to the printer. Ones that have sat on a shelf for years and fail on installation. I could go on, but I’m sure you get the idea. I use http://directpreciseimaging.com/ Mostly because I set him up in business and he’s local to me. I have very few problems with his products.

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HP LaserJet 5SI

Toner chip resetter or cheap replacement source
ANSWER : There is a chip resetter if you can find someone who sells it. http://apexmic.info/how-to-reset-chip-dell-1250c.h…Otherwise, do a google search on dell 1250c reset chips. There are lots of suppliers.

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HP LaserJet 5SI

toner loose
ANSWER : That would indicate the fuser is not getting hot. Of course, that should cause an error and shut down the printer. Could be a piece of paper wrapped around the heat roller preventing the transfer of heat to the printed sheet.

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HP LaserJet 5SI

Toner cartridge full, printer displays: "empty needs replacing"
ANSWER : I once went to a customer who had a similar issue. They had installed new cartridges and judging from the box, they looked OEM. Strange thing was they felt empty when lifted and they were missing the chip on the outside that tells the printer it is installed and keeps track of how many copies were printed with that cartridge. The printer has no other way of knowing if the cartridge is full or empty.

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HP LaserJet 5SI