2009 HP Designjet T770 & T1200 Large-Format Printer Service Manual

The HP Designjet T770 & T1200 printer series service manual, version 3 dated October 21, 2009, covers fault isolation, component replacement, and service calibration. It distinguishes model-specific hardware and includes separate guidance for the T770 Hard Disk Version and supported accessories.

• Fault diagnosis: System error descriptions, corrective-action tables, initialization self-tests, front-panel service menus, and diagnostic boot mode.

• Print quality and ink delivery: Printhead reliability and alignment tests, advanced diagnostic plots, ink-supply troubleshooting, IDS tests, and tube-purging procedures.

• Mechanical repair: Illustrated removal and installation of the belt, carriage assembly, scan-axis motor, media advance drive, cutter, and paper-handling components.

• Electronics and sensors: Formatter, hard disk drive, main PCA, power supply, trailing cable, drop detector, and line sensor replacement, with component-specific diagnostic tests.

• Service calibration: Paper advance, drop detector, line sensor, and sheet sensor calibration, plus a replacement-to-calibration reference table.

• Parts and maintenance: Exploded assembly drawings, model-specific parts tables, cleaning and lubrication guidance, life counters, and preventive maintenance kits.

This manual is suited to printer service technicians familiar with electronic assemblies and ESD precautions; internal repairs call for service tools and engineering-menu diagnostics.

Fault Isolation and Diagnostic Prints

The error-code section distinguishes continuable faults from conditions requiring service intervention. A separate LED interpretation table supports diagnosis when the front panel is blank, linking formatter and power-supply indications to the affected assemblies.

Firmware and disk faults: The SE 79:04 appendix separates recurring job-related failures from random firmware exceptions, including memory leaks and hardware-related causes. Firmware updating in diagnostic boot mode, printer-log collection, and obtaining the diagnostics package are also covered.

Hard Disk Recovery and File System Check are separate utilities. Recovery erases the hard disk and restores firmware, an important distinction when choosing between the documented recovery options.

Print-quality diagnosis: The Image Quality Service Best Plot separates printhead reliability, printhead alignment, and printhead/paper-advance checks. Advanced Diagnostic Prints provide further detail for interpreting defects. These tests help distinguish printhead problems from media-advance or configuration issues before selecting replacement parts.

The 86:01 entry identifies a possible paper jam and points to scan-axis testing. It should not be treated as a diagnosis of a failed media advance drive.

Component Replacement and Model Differences

Illustrated procedures cover the formatter, hard disk drive, carriage PCA, encoder components, ink supply station, service station, and paper-path hardware. The T1200-specific sections include bi-stable springs, the lower roll cover, and lower roll supports.

Post-repair checks: The Service Calibration Guide links removed components to the required diagnostic tests and calibrations. It also applies when a component was removed only to reach another assembly, helping technicians identify the checks needed after reassembly.

Handling cautions: The trailing-cable installation section addresses cable routing and crease damage. The spindle procedure identifies an end-specific removal hazard that can damage the spindle’s black end.

Service Tools, Parts Drawings, and Maintenance

The required-tools section identifies Toolkit P/N Q6683-67001. It lists the media driver adjustment tool, manual pinch arm alignment tool, and spring insertion tool. Service paper-advance calibration requires Paper Advance Calibration Kit Q6687-60093.

Illustrated references include Center Covers (Front), Carriage Assembly, Scan-Axis Assemblies, and Paper Path Assemblies (Front/Rear). Their numbered callouts connect to parts tables and replacement procedures.

Preventive Maintenance Kit #1, CH538-67024, groups carriage, scan-axis motor, tube-system/trailing-cable, and belt components. Kit #2, CH538-67040, covers the service station. The lubrication kit is separate from Kit #1.

A Preview of Calibration Media Requirements

These examples show a small selection of the manual’s calibration and diagnostic requirements.

The full line-sensor calibration uses glossy roll paper at least 24 inches wide. The manual distinguishes this from the manual-loading process, which performs only a partial calibration.

The Image Quality Diagnostic Print requires A3 or B-size media or larger. Its instructions also explain why the paper type matters when comparing diagnostic output with the reported print defect.

Searchable PDF with Chapter Bookmarks

Text search and illustrated references: The PDF contains embedded searchable text and bookmarks covering troubleshooting, error codes, diagnostics, service utilities, parts, replacement procedures, and maintenance. Small front-panel screenshots benefit from zooming; the illustrated parts callouts support cross-reference to the accompanying tables.

One printable English PDF download contains 383 pages in total, including the cover, copyright page, contents, and preliminary pages. These pages are already included in the total.