asked Mar 3, 2018 at 1:55pm
Hp HP LaserJet 4

questions about toner cart, blades, sources

My trusty HP4 started making random vertical streaking today. I can see matching streaks on the drum, indicating a worn wiper blade, right? The cart still has enough toner for a few more thousand pages, so I'd prefer to clean the drum and replace the blade, apparently an easy job as noted by others here.

I found a dealer (Partsmart) that sells individual blades, but I saw a report elsewhere in this forum (see last post in this thread: that their blades are sometimes hard. I print less than 1k pgs/yr so I can't justify buying a 10-pak.

Can someone recommend a source for fresh individual blades?

Otherwise, I'll need to buy another toner cartridge. As I understand it, HP no longer manufactures this cart, so any 'new' OEM carts sold online are actually old stock with blades that are well past their prime. I avoid 'compatible' or remanufactured carts, since these tend to be a crapshoot.

As I recall, this site used to sell new old-stock OEM carts with fresh wiper blades. That's a great idea. Does anyone in the US still sell these?

It is hard to find single blades. Most everyone sells 10 packs. Hard to find people who still sell hp4 cartridges since there is so little demand for them.

by moe on Mar 3, 2018 at 11:49pm Add comment

Thanks for prompt reply, Moe.

Since posting my question, I did a google search and LD Products remanufactured carts for hp4 seem to get uniformly high reviews. Any experience or feedback on that brand?

by ginahoy on Mar 4, 2018 at 12:08am Add comment

For those who are interested, thought I would report that I was able to disassemble the cartridge and clean the wiper blade. It's working again like new! No more streaks, at least for now.

This is an OEM cartridge that I purchased last year, so it's probably several years old. Even still, the wiper blade was only slightly yellowed and there was no sign of cracking or pitting. It only has about 1k pages, so using this technique, it should last several more years.

I cleaned the blade with a damp paper towel. I also used wetted paper towels to clean the PCR (roller). And I cleaned the visibly streaked drum with isoprophyl alcohol and a cotton swap. Q-tips and compressed air are helpful when cleaning the shell that holds the above components. But be aware that this assembly also contained a fair amount of waste toner in the chamber beneath the wiper blade. You can either carefully empty that or take care not to turn the assembly upside down or blow compressed air in the vicinity of the slot (as I learned the hard way). Yeah, this job is a bit messy but it was actually pretty easy, and I didn't have any problem cleaning the toner off my hands afterward.

BTW, I didn't touch the toner hopper assembly. I followed the instructions here, through step 10:

by ginahoy on Mar 9, 2018 at 5:32am Add comment