HP Envy 4500 print cartridge error

The office next door to my former office went through 3 or 4 of those printers. They all died with a similar problem that was probably caused by replacing the print cartridge while the printer power was turned on. Notice how close the contact pads are on the cartridge: It doesn't take much to short the contacts. I couldn't determine if it was the printer, the cartridge, or both that died. Anyway, wipe the cartridge and the matching contacts on the carriage with a wet cloth until all the ink splotches have been cleaned and try again. If that doesn't work, give up. If that fixes it, read the entire article and then decide if you want to continue dealing with this abomination.

Yeah I think it's hopeless. I'll grab a laser all-in-one ideally something with a phone jack for faxing, look to be a couple gently-used candidates on CL around here.

I went to the laser type all in one a while back as all I do is in black ink. They are relative inexpensive . I hope to never buy the HP brand printers again. They do crazey things with the ink cartrages and some good ones may show up as bad if they are very old. The laser toner does not dry out like the ink ones if you go a long time between printing like I do.

I love my Panasonic Penwriter, from 1986, my parents had one and a lot of grade-school reports were made on an electronic typewriter like this one:

Got one new-old-stock a while back and the original pens sealed in their packaging still work fine. I think they're still made by one company in Germany, they're basically the same pens for the Atari 800 pen plotter...it works OK as a (slow) serial port printer for text, also.

In theory it should be able to draw vector graphics also but I'd have to write a conversion software from the vector format to the bespoke set of commands the machine takes for drawing graphics. I bet schematics would look very nice plotted out by it.

The cartridge is supposed to be changed with the printer on, otherwise it is parked. Output connections are supposed to be properly current limited and if this is really what happens maybe a diode or fuse resistor went open, may be repairable.

True. Opening the lid will move the cartridge carrier to roughly mid travel so that the cartridges are accessible: I don't do it that way. What I've done to reduce failures is follow the instructions to the point where cartridges are accessible. Then, pull the power plug from the AC wall receptacle, or unplug the power cord at the printer. The cartridge carrier will remain accessible and not retract. Don't leave it like this for very long as the cartridge tend to drip ink in this position. When the internal power supply capacitors have discharged (about 15 seconds), I replace the cartridges and re-apply power. Once I convinced users to use this procedure, the number of printer failures were drastically reduced. However, failures didn't go to zero. My guess(tm) is that someone didn't follow my procedure and swapped cartridges with the power applied and then lied that they did it correctly.

I've tried to troubleshoot to the component level on only one such printer and failed. The lack of a schematic, difficulty identifying some parts, and the need to build extension cables so the PCB is accessible were the major problems. I suspect that access to the factory diagnostic software would have helped, but I suspect it would simply say "replace the PCB". When I can buy a used and working replacement printer on eBay for about $50 total, there's not much incentive to repair the broken printer. At my previous shop rate of $75/hr, break even with a replacement used printer is 40 minutes of labor (excluding parts cost). I could not do the repair in 40 minutes.

I don't know what killed 3 or 4 of these printers, but it keeps happening. I might have some luck identifying the culprit if I had a working printer next to the broken printer to use for comparison. That's a major project which will likely cost more than it's worth.

For what it's worth, my guess(tm) is that the outputs driving the piezoelectric heads is not properly protected. Something might be shoving power back into the driver IC, possibly when a cartridge is inserted at a slight angle causing the pads on the cartridge to short two adjacent pins together. I haven't spent any time investigating this theory beyond a quick inspection which showed that it was almost possible to short adjacent contacts. Measure the pad diameter on the cartridge. Measure the gap between adjacent pins on the carrier. In theory, there is sufficient clearance, but it's VERY close.