Page 3 - Repair Manual
HP LaserJet Pro 400 M401 Printer Series Repair Manual
Page 5 - Conventions used in this guide
Conventions used in this guide TIP: Tips provide helpful hints or shortcuts. NOTE: Notes provide important information to explain a concept or to complete a task. CAUTION: Cautions indicate procedures that you should follow to avoid losing data or damaging the product. WARNING! Warnings alert you to...
Page 7 - Table of contents
Table of contents 1 Removal and replacement ................................................................................................ 1 Removal and replacement strategy ............................................................................................. 2 Electrostatic discharge .......
Page 11 - List of tables
List of tables Table 2-1 Order parts, accessories, and supplies .................................................................................... 60 Table 2-2 Related documentation and software ...................................................................................... 60 Table 2-3...
Page 13 - List of figures
List of figures Figure 1-1 Phillips and Pozidriv screwdriver comparison ............................................................................ 3 Figure 1-2 Parts-removal order ................................................................................................................ 5...
Page 17 - Removal and replacement
1 Removal and replacement ● Removal and replacement strategy ● Service approach ● Removal and replacement procedures ENWW 1
Page 18 - Electrostatic discharge
Removal and replacement strategy WARNING! Turn the product off, wait 5 seconds, and then remove the power cord before attempting to service the product. If this warning is not followed, severe injury can result, in addition to damage to the product. The power must be on for certain functional checks...
Page 19 - Service approach; Before performing service
Required tools ● #2 Phillips screwdriver with a magnetic tip and a 152 mm (6 in) shaft length ● Small flatblade screwdriver ● Needle-nose pliers ● ESD mat (if one is available) or ESD strap ● Penlight (optional) CAUTION: Always use a Phillips screwdriver (callout 1). Do not use a Pozidriv® screwdriv...
Page 20 - After performing service
● Remove the toner cartridge. ● Remove the Tray 2 cassette. After performing service ● Plug in the power cable. ● Reinstall the toner cartridge. ● Reinstall the Tray 2 cassette. ● Load paper in the product. Post-service test Perform the following test to verify that the repair or replacement was suc...
Page 21 - Parts removal order
Parts removal order Use the following diagram to determine which parts must be removed before removing other parts. Figure 1-2 Parts-removal order Component Remove Remove Remove Remove Remove Remove Toner car tr idge Tr ay 2 c as set te Tr ay 1 pic kup r oller Lef t co ver Tr ay 2 casse tte Right co...
Page 22 - Removal and replacement procedures; Rollers
Removal and replacement procedures Rollers Multipurpose (MP) tray pickup roller 1. Open the toner cartridge door, and then remove the toner cartridge. 2. Pull back and hold the pickup roller cover (callout 1), press the tabs (callout 2) on both ends of the pickup roller away from the roller — which ...
Page 23 - Reinstallation tip
3. On the left side of the product, release the innermost tab (callout 1) at the center of the gear, and then remove the gear (callout 2). NOTE: The gear is composed of two pieces. Releasing the outer tab does not remove the entire gear assembly and exposes an internal spring in the gear. Figure 1-4...
Page 25 - Tray 2 and optional Tray 3 pickup roller
6. Pull up on the top edge of the separation pad to release it from the product. Figure 1-8 Remove the MP tray separation pad (5 of 5) Reinstallation tip When reinstalling the pickup roller shaft assembly, make sure that the flat part of the pickup roller is directly over the separation pad. Tray 2 ...
Page 26 - Tray 2 and optional Tray 3 separation pad
3. Push the pickup roller to the left to release the right side roller, and then pull the roller out of the product. Figure 1-10 Remove the Tray 2 or Tray 3 pickup roller (2 of 2) 4. Tray 2 and optional Tray 3 separation pad 1. Remove the tray cassette from the product. 2. Locate the separation pad ...
Page 27 - Covers and control panel; Left cover
Covers and control panel Left cover NOTE: No tools are necessary to remove this cover. However, a small flat-blade screwdriver might be helpful in releasing some of the tabs that hold the cover to the product chassis. 1. Remove the Tray 2 cassette. 2. Open the toner cartridge door and the rear jam a...
Page 28 - Right cover
Right cover NOTE: No tools are necessary to remove this cover. However, a small flat-blade screwdriver might be helpful in releasing some of the tabs that hold the cover to the product chassis. 1. Remove the Tray 2 cassette. 2. Open the toner cartridge door and the rear jam access door. 3. Grasp the...
Page 29 - Top cover with LCD control-panel module
Top cover with LCD control-panel module 1. Remove the following components: ● Tray 2 cassette ● Right cover. See Right cover on page 12 . ● Left cover. See Left cover on page 11 . 2. Open the toner cartridge door and the rear jam access door. 3. On the left side of the product, disconnect one flat c...
Page 30 - LCD control panel
5. On the top of the top-cover assembly, remove two screws (callout 1). Figure 1-16 Remove the top-cover assembly and LCD control-panel module (3 of 3) 11 6. Lift the top-cover assembly off of the product to remove it. NOTE: You do not need to remove the control panel from the top cover assembly, un...
Page 32 - Top cover with touchscreen control-panel module
Top cover with touchscreen control-panel module 1. Remove the following components: ● Tray 2 cassette ● Right cover. See Right cover on page 12 . ● Left cover. See Left cover on page 11 . 2. Open the toner cartridge door and the rear jam access door. 3. On the left side of the product, disconnect on...
Page 34 - Touchscreen control panel
Touchscreen control panel 1. Remove the following components: ● Tray 2 cassette ● Right cover. See Right cover on page 12 . ● Left cover. See Left cover on page 11 . ● Top cover assembly. See Top cover with touchscreen control-panel module on page 16 . 2. On the underside of the top cover assembly, ...
Page 36 - Duplex models only
Rear cover, rear door, and feed assembly CAUTION: The fuser can be hot while the product is in use. Wait for the fuser to cool before working in that area. 1. Remove the following components: ● Tray 2 cassette ● Right cover. See Right cover on page 12 . ● Left cover. See Left cover on page 11 . 2. O...
Page 39 - Cartridge door and front cover assembly
Cartridge door and front cover assembly NOTE: The cartridge door assembly includes the cartridge door, Tray 1, and the front cover. 1. Remove the following components: ● Tray 2 cassette ● Right cover. See Right cover on page 12 . ● Left cover. See Left cover on page 11 . 2. Open the toner cartridge ...
Page 42 - Main assemblies; Laser scanner assembly
Main assemblies Laser scanner assembly WARNING! ESD sensitive component. CAUTION: Do not bend or fold the flat flexible cables (FFCs) during removal or installation. Also, do not straighten pre-folds in the FFCs. You must make sure that all FFCs are fully seated in their connectors. Failure to fully...
Page 43 - Registration roller assembly
4. Remove four screws (callout 1), and then remove the laser scanner assembly. Figure 1-33 Remove the laser scanner assembly (2 of 2) 1 Registration roller assembly 1. Remove the following components: ● Tray 2 cassette ● Right cover. See Right cover on page 12 . ● Left cover. See Left cover on page ...
Page 45 - Fuser assembly and paper feed guide
5. Remove four screws (callout 1), and then remove the gear cover (callout 2). Figure 1-36 Remove the registration assembly (3 of 3) 3 2 1 6. Slightly raise the right end of the assembly (callout 3), and then slide it to the right and lift it up to release it and remove it from the product. Reinstal...
Page 48 - Face down drive or duplex drive assembly
7. Disconnect three connectors (callout 1), remove two screws (callout 2), and then remove the fuser (callout 3). Figure 1-41 Remove the fuser (5 of 5) 2 3 1 Face down drive or duplex drive assembly Simplex products have a face-down-drive assembly installed. Duplex products have a duplexing-paper- f...
Page 50 - Solenoids; Tray 1 solenoid
Solenoids Tray 1 solenoid 1. Remove the following components: ● Tray 2 cassette ● Left cover. See Left cover on page 11 . 2. Open the toner cartridge door and the rear jam access door. 3. On the left side of the product, disconnect one connector (callout 1), and then release the wires from the wire ...
Page 51 - Duplex solenoid
4. Remove one screw (callout 1), and then remove the Tray 1 pickup solenoid. Figure 1-45 Remove the Tray 1 pickup solenoid (2 of 2) 1 Duplex solenoid NOTE: This section applies to duplex models only. 1. Remove the following components: ● Tray 2 cassette ● Right cover. See Right cover on page 12 . ● ...
Page 53 - Motors and fans; Main motor
Motors and fans Main motor 1. Remove the following components: ● Tray 2 cassette ● Right cover. See Right cover on page 12 . ● Left cover. See Left cover on page 11 . ● Top cover assembly. See Top cover with touchscreen control-panel module on page 16 or Top cover with LCD control-panel module on pa...
Page 55 - Fan
6. Remove three black-screws (callout 1) and one silver-screw (callout 2), release two tabs (callout 3), and then remove the main motor (callout 4) and the cable guide (callout 5) together. Figure 1-50 Remove the main motor (4 of 4) 1 4 5 3 2 Reinstallation tip Remember the location from where you r...
Page 57 - Engine controller assembly (DC controller) PCA
Printed circuit-board assemblies (PCAs) Engine controller assembly (DC controller) PCA WARNING! ESD sensitive component. CAUTION: When removing the engine controller assembly (callout 1) from the rear of the product, the portion (callout 2) on the left side of the assembly might be hot. Allow enough...
Page 64 - Formatter PCA; Wireless models only:; Wireless PCA
Formatter PCA WARNING! ESD sensitive component. 1. Remove the following components: ● Tray 2 cassette ● Left cover. See Left cover on page 11 . ● Wireless PCA (wireless models only). See Wireless PCA on page 48 . 2. On the left side of the product, disconnect any connectors and flat cables (callout ...
Page 65 - Power switch PCA
2. On the left side of the product, release two tabs (callout 1), pull the lower left-hand corner of the PCA to disconnect the connector on the back of the PCA, and then pull the PCA away from the product. Figure 1-66 Remove the wireless PCA 1 Power switch PCA The power switch PCA is located in the ...
Page 67 - Connecting PCA
4. Release one tab (callout 1), and then pull the PCA out of the front cover. Figure 1-69 Remove the power-switch PCA (3 of 3) 1 Connecting PCA The connecting PCA is located on the product right side, below the control panel. 1. Remove the following components: ● Tray 2 cassette ● Right cover. See R...
Page 68 - Miscellaneous parts; Transfer roller
Miscellaneous parts Transfer roller CAUTION: Do not touch the sponge surface of the roller unless you are replacing the roller. Skin oils on the roller can cause print-quality problems. Always wear latex gloves when handling a transfer roller for reinstallation or replacement. 1. Open the toner cart...
Page 71 - Optional paper feeder paper sensor PCA
3. Disconnect three connectors (callout 1), and then remove one screw (callout 2) to remove the driver PCA. Figure 1-75 Remove the optional paper feeder driver PCA (2 of 2) 2 1 Optional paper feeder paper sensor PCA 1. Remove the right cover. 2. On the right side of the unit, remove one screw (callo...
Page 75 - Parts and diagrams
2 Parts and diagrams NOTE: In this chapter, part numbers are listed only for available replaceable parts. ● Order parts by authorized service providers ● How to use the parts lists and diagrams ● Assembly locations ● Covers, panels, and doors ● Internal assemblies ● Input devices ● Alphabetical part...
Page 76 - Order parts by authorized service providers; Order replacement parts; Whole-unit replacement part numbers
Order parts by authorized service providers Order replacement parts Table 2-1 Order parts, accessories, and supplies Order supplies and paper www.hp.com/go/suresupply Order genuine HP parts or accessories www.hp.com/buy/parts Order through service or support providers Contact an HP-authorized servic...
Page 78 - How to use the parts lists and diagrams
How to use the parts lists and diagrams The figures in this chapter show the major subassemblies in the product and their component parts. A parts list table follows each exploded view assembly diagram. Each table lists the item number, the associated part number, and the description of each part. I...
Page 79 - Assembly locations
Assembly locations HP LaserJet M401a, M401n, M401d models Figure 2-1 Assembly locations: HP LaserJet M401a, M401n, M401d models 1 2 3 4 5 6 7 8 9 10 11 Table 2-5 Assembly locations: HP LaserJet M401a, M401n, M401d models Item Description Item Description 1 Cartridge door 7 Rear cover (HP LaserJet M4...
Page 81 - Optional paper feeder
Optional paper feeder Figure 2-3 Assembly locations: optional paper feeder 1 2 3 Table 2-7 Assembly locations: optional paper feeder Item Description Item Description 1 Positioning pins 3 Tray 3 cassette 2 Option interface connector ENWW Assembly locations 65
Page 86 - Internal assemblies
Internal assemblies Figure 2-6 Internal components (1 of 5) A A A03 A07 A06 A05 A02 A04 A16 A17 A15 A12 A13 A14 A14 A03 A09 A01 A03 A10 A11 A18 A08 1 70 Chapter 2 Parts and diagrams ENWW
Page 98 - Input devices; 00-sheet paper feeder
Input devices 500-sheet paper feeder Paper feeder covers Figure 2-12 Paper feeder covers 1 3 2 82 Chapter 2 Parts and diagrams ENWW
Page 115 - Index
Index A accessories ordering 60 after-service checklist 4 C cartridge ordering 60 part number 60 cautions iii checklists after-service 4 preservice 3 conventions, document iii covers left, removing 11 locations 66 parts list 66 right, removing 12 top, removing 13, 16 covers, removing rear 20 D diagr...
