LaserJet Problem

Shpyda

Printing Apprentice
Joined
May 6, 2019
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Location
Grand Rapids, MI
Printer Model
HP LaserJet Pro M402n
Hoping someone can diagnose my problem.

Just bought a "new" used HP laserjet pro m402n. Everything setup perfectly and it is on the most current firmware. It is configured to print through a network connection and I've purchased two refurbished toner cartridges.

When I print a document it seems to do a fairly good job as far as a nice and clear print. The problem comes in to play when the printer goes into a sleep mode. If it sleeps for any amount of time and I send a document to print, it will wake up and print an all black page. If I print again moments later it will print a page with lots of horizontal black lines. If I continue to send it gets more and more clear until it finally spits out a good looking copy.

I'm thinking it has something to do with the time it takes the printer to warm up after coming out of the sleep mode, but I'm not sure exactly what that would be attributed to. I get the exact same results with both of the refurbished toner cartridges.

Can someone please offer insight as to what would cause this issue and what I can do to resolve it?

Thanks,
Ryan
 

Shpyda

Printing Apprentice
Joined
May 6, 2019
Messages
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Reaction score
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Points
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Location
Grand Rapids, MI
Printer Model
HP LaserJet Pro M402n
I don't know the printer, but here is the troubleshooting manual and the repair manual, in case you didn't have them already.

I appreciate the manuals very much. I ruled out bad toner cartridges so I’m thinking it’s either going to be the fuser or the high voltage power supply. I ordered the power supply as it was the cheapest option and will use the repair guide to walk me through the install.

I realize that these machines are relatively complex, but considering how tried and true they are, it seems like I’d be able to find more absolute answers to these types of questions. I’ll definitely post my results so the next guy knows exactly what to do.

Thanks again for the resources PeterBJ
 

Shpyda

Printing Apprentice
Joined
May 6, 2019
Messages
3
Reaction score
4
Points
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Location
Grand Rapids, MI
Printer Model
HP LaserJet Pro M402n
My problem is solved!!

The problem once again:

I picked up a used HP LaserJet M420n(I think this diagnosis would apply to any laser printer though). I put in an recycled toner cartridge and right off the get go I was hearing a steady high pitched sound(almost like my ears were ringing) that was continuing as long as the printer was awake. It sucked, but I pushed on.

When I went to print there were specks on the page and some darker areas as well, but the text was clear. I ran a few cleaning cycles and it actually seemed to help, but I wasn't thrilled with the quality still. The printer went into a sleep mode and sat for a few, and when I sent a document it woke to print and produced an entirely black page. Subsequent prints got progressively better until there were just light specks(it was almost like something was taking a while to heat up or something). Every time I let the printer go to sleep it would again print a black page upon waking.

Frustrating!!!

I searched and couldn't find an absolute diagnosis for such an issue, but I was able to find hints here and there and it was starting to sound like a High Voltage Power Supply(HVPS). My other option was to try a new fuser, but the power supply was only $28 so I figured that I'd start there.

Fast forward a few days, power supply arrived and I followed the guide provided by PeterBJ to open the printer and install it.

Very happy to say that upon completion(about 30 minutes, be careful people) the printer fired up and everything is in working order. No more high pitched sound. No more specks on page. No more black page upon waking from sleep state. Just crisp and clear prints and working like a champ.

I'm writing so if anyone in the future is searching for similar issues, they might stumble across this post and come to a quicker diagnosis than I was able to.

Thanks again for the help PeterBJ, the repair guide you provided was a lifesaver!
 
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