HP LaserJet pro 400 series; solenoid won't energize.
 

Hello!
Solenoid is fine; not sticking and energizes with external source. Needless to say MP feed won't pickup paper. Also the printer spits out a single blank paper from Tray 2 whenever powered. Any ideas?

HP LaserJet pro 400 series; solenoid won't energize.
 

On 26.02.2020 09:11, wrote:
Hello!
Solenoid is fine; not sticking and energizes with external source. Needless to say MP feed won't pickup paper. Also the printer spits out a single blank paper from Tray 2 whenever powered. Any ideas?

Looks like it's confused about the paper sheet location, so to speak.

Check all limit switches and endstops (optical and mechanical)

HP LaserJet pro 400 series; solenoid won't energize.
 

Thank you for replying. Sensors seem to be okay. Also blank paper spitting is only at the time of powering on the printer, as if that makes any sense.

HP LaserJet pro 400 series; solenoid won't energize.
 

I will guess that there is a sensor jammed/clogged such that it believes there is something in the pathway that it tries to reject - spits out a piece of paper. When that sensor does not clear, it shuts down. Have you cleaned the optical sensors? Either 91% Isopropyl alcohol and a very soft cloth, or distilled water and that same cloth.

Paper dust is is a very real issue, especially on heavily used copiers. Best of luck with it.

Peter Wieck
Melrose Park, PA

HP LaserJet pro 400 series; solenoid won't energize.
 

Thanks Wieck, for your insight. Optical sensors are clean, and no error code reported. Though MP feed solenoid won't energize thus no paper pickup from MP tray with error Tray 2 Jam error when print attempted with paper in Tray 1.

HP LaserJet pro 400 series; solenoid won't energize.
 

On 26.02.2020 17:24, wrote:
Thanks Wieck, for your insight. Optical sensors are clean, and no error code reported. Though MP feed solenoid won't energize thus no paper pickup from MP tray with error Tray 2 Jam error when print attempted with paper in Tray 1.

If you get a Tray 2 jam error, and theres no paper jam, then the paper
jam sensors are faulty. Check these again with a multimeter if they are
mechanical, and clean the optical ones out throughly as Peter Wieck said

--
Nife Sima - the lower earth crust

HP LaserJet pro 400 series; solenoid won't energize.
 

On Wednesday, February 26, 2020 at 11:24:09 AM UTC-5, wrote:
Thanks Wieck, for your insight. Optical sensors are clean, and no error code reported. Though MP feed solenoid won't energize thus no paper pickup from MP tray with error Tray 2 Jam error when print attempted with paper in Tray 1.

not sure how to parse the last sentence. Is there a period missing?
Though MP feed solenoid won't energize thus no paper pickup from MP tray with error. Tray 2 Jam error when print attempted with paper in Tray 1.

If parsed this way, seems that cpu is confused about status/state of paper trays.....so check the tray sensors.
A HP service manual would be very helpful....do you have one?

HP LaserJet pro 400 series; solenoid won't energize.
 

On Wednesday, February 26, 2020 at 11:54:07 AM UTC-5, three_jeeps wrote:
On Wednesday, February 26, 2020 at 11:24:09 AM UTC-5, wrote:
Thanks Wieck, for your insight. Optical sensors are clean, and no error code reported. Though MP feed solenoid won't energize thus no paper pickup from MP tray with error Tray 2 Jam error when print attempted with paper in Tray 1.

not sure how to parse the last sentence. Is there a period missing?
Though MP feed solenoid won't energize thus no paper pickup from MP tray with error. Tray 2 Jam error when print attempted with paper in Tray 1.

If parsed this way, seems that cpu is confused about status/state of paper trays.....so check the tray sensors.
A HP service manual would be very helpful....do you have one?


forgot to add: you say solenoid checks fine on external source...did you check the solenoid signal path?..Signal present but not getting through?

HP LaserJet pro 400 series; solenoid won't energize.
 

Yeah! Well. Do have the service manual. As for the signal path, any detailed advice on howto?

HP LaserJet pro 400 series; solenoid won't energize.
 

I do have the service manual. As for the signal path, any detailed advice on howto? Thank you for your kind help.

HP LaserJet pro 400 series; solenoid won't energize.
 

Do have the service manual. As for the signal path, any detailed advice on howto? And thank you for your kind help.