633 Instructions for Changing the RTC (Real-Time Clock) Battery

633 Disassembly

  • Observe standard practices and precautions when working with electronic assemblies.
  • Work in an ESD safe environment. Ground yourself, tools and equipment to prevent damage from static discharge.
  • Remove and/or disconnect power sources from equipment such as AC Adapters and batteries. Allow circuits time to drain any stored charges.
  • Disconnect inputs and outputs to prevent connector damage during disassembly and assembly.
  • Use proper, well-maintained tools.

NOTE: After servicing the unit, re-assembly should be aided by scrolling through these steps in reverse order to be certain that no small items are missed.

Removing the Top Panel.

1. Remove 7 screws from the top cover. Some 633s have an additional screw near the front edge of the top panel; remove this screw, if present, as well.

2. Lift the top cover off and set it carefully aside.

NOTE: Some 633s have an additional screw (P/N 1259) near the front edge. Remove this screw as well.

Removing Old Battery

The RTC battery is located in a holder just behind the digital module.

The RTC battery is in a holder and located close to other components, leaving no room for fingers to grasp it. Here are two methods that can make removal easier:

Method 1

1. Lay a wide rubber band over the coin cell and then grasp it with a long-nose plier. The rubber band improves the plier’s grip and prevents electrical contact with the battery.

2. Simply pull up to remove the battery.

Method 2

1. Attach a piece of tape to the exposed portion of the coin cell. Electrical tape or ‘duct tape’ works well.

2. Then pull up on the tape to remove the battery.

Install the new RTC Battery

The 633 uses a standard coin cell (P/N CR2032) commonly sold where batteries are found.

1. Set the coin cell into the top of the holder with the side marked with the ‘+’ sign facing toward the right (Output) end panel of the 633.

2. Press the coin cell down into the holder until it is fully in-place. Only about one third of the cell should extend above the holder.

Replace the Top Panel

1. Place the top panel into position; the top edges of the front, back and side panels must fit into recesses in the under-side of the top panel, so some small movement in each direction while pressing down may be necessary to line up the top with the sides. It may also be necessary to push in on the back (battery tray) panel. Also check that the pin on the top edge of the media door lines up with a hole in the top panel.

2. Replace all screws.

Set Time/Date

1. Power on the 633.

2. Press the MENU button.

3. Select System > Set Time/Date, and then use the HP encoder to enter current time and date.

4. Power the 633 OFF, disconnect all power sources and hold the MENU button until the blue LED stops blinking.

5. After a few seconds, power the 633 back on and check the time/date settings to be sure they are still accurate.