3-798-610-22 (1)

Portable MiniDisc Recorder

Operating instructions

1995 by Sony Corporation
SONY MZ-B3 (E) 3-798-610-22(1)

WARNING

To prevent fire or shock hazard, do not expose the unit to rain or moisture. To avoid electrical shock, do not open the cabinet. Refer servicing to qualified personnel only.

Caution

The use of optical instruments with this product will increase eye hazard.
Consult the dealer or an experienced radio/TV technician for help. You are cautioned that any changes or modifications not expressly approved in this manual could void your authority to operate this equipment.
IN NO EVENT SHALL SELLER BE LIABLE FOR ANY DIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY NATURE, OR LOSSES OR EXPENSES RESULTING FROM ANY DEFECTIVE PRODUCT OR THE USE OF ANY PRODUCT.

Owners Record

The serial number is located inside the battery compartment and the model number is located at the bottom. Record the serial number in the space provided below. Refer to them whenever you call upon your Sony dealer regarding this product. Model No. MZ-B3 Serial No.__________________________

Information

For Customers in the USA
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, used, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one more of the following measures: Reorient or relocate the receiving antenna. Increase the separation between the equipment and the receiver. Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.

Welcome!

Welcome to the world of the MiniDisc! Here are some of the capabilities and features you'll discover with the new MiniDisc (MD) Recorder. Long-time recording in monaural sound You can record for up to 148 minutes on a 74-minute MD by using monaural recording. You can record in stereo sound for up to 74 minutes. A microphone and a speaker built in the recorder You can record and play back an MD anywhere you go. Digital VOR (Voice Operated Recording) function The recorder starts and stops recording automatically in response to the sound. The recorder's memory makes precise starting of recording possible. With this function, you can dictate easily. Fast playback function You can reduce the listening time. You can play an MD either 1.6 or 2.2 times as fast as the normal playback speed. Two kinds of track marks You can record two different kinds of track marks: regular track marks and special track marks. You can locate the special track marks independently of the regular ones. Position indicator The display shows you the current location on the MD. Date and time stamp function The built-in clock allows you to record the date and time whenever you make a recording. Title function You can see disc and track titles in the display while you are playing an MD that has been electronically labeled.

Table of contents

Recording an MD right away!..6 Playing an MD right away!..8 Various ways of recording..10
Dictating (Digital VOR function).. 10 Recording in stereo with an external microphone.. 11 Recording from other equipment.. 12 Track marking while recording.. 13 Tips on recording... 15 To monitor the sound being recorded.. 15 To know the recording condition.. 15 To protect a recorded MD.. 15 To know the remaining time, etc.. 16 Setting the clock to stamp the recorded time.. 17

Various ways of playback..19
Listening at a fast speed.. 19 Playing tracks repeatedly... 19 Tips on playback... 20 To know the time and track name.. 20 To lock the controls (Hold function).. 21 Listening with other equipment... 22
Editing recorded tracks..23
Track marking a recording... 23 Erasing a track mark... 24 Erasing a track.... 25 Erasing a whole disc... 26

Power sources..27

Using on house current... 27 Using on a lithium ion rechargeable battery.. 27
Additional information..29
Precautions.... 29 Troubleshooting... 32 System limitations.... 34 Error messages... 35 Specifications... 37 What is the MD?... 38 Looking at the controls... 40
Recording an MD right away!
Record an MD through the built-in microphone. The recorded sound is monaural, and you can record for up to 148 minutes on a 74-minute MD or up to 120 minutes on a 60-minute MD.
1 Install three alkaline batteries.

(bottom)

Three size AA (LR6) alkaline batteries
2 Insert a recordable MD.
1 Slide OPEN and open the lid.
2 Insert a recordable MD with the label side facing up, and press the lid down to close.

3 Record an MD.

Sound source Microphone

Press rREC.

"REC" and "MONO" appear in the display, and recording starts from the beginning of the disc. The level of the recorded sound is adjusted automatically.
To stop recording, press p (stop).
"Toc Edit" flashes to store data of the recording (the tracks start and end points, etc.). Do not move or jog the recorder or disconnect the power source while the indication is flashing in the display. When the recorder completes storing the data, the r REC button will be released.

To Pause

Press P* Press P again to resume recording. END SEARCH, then press rREC. (, + or = to find point to start recording, and press p to stop. Then press rREC. p and open the lid.*
If the recording does not start
Make sure the recorder is not locked (page 21). Make sure the MD is not recordprotected (page 15).
Record from the end of the previous recording Record over partway through the previous recording
The alkaline batteries' life
You can record an MD with new alkaline batteries for 3 hours.
Display window while recording
Elapsed time of the track being Track number recorded

Remove the MD

* Once you open the lid, the point to start recording will change to the beginning of the first track. When recording on a recorded MD, check the point to start recording on the display.
Position indicator (shows the current location on the MD)
Playing an MD right away!
Play an MD you recorded on or a premastered MD. You can hear the playback sound in monaural through the built-in speaker. For stereo sound, play an MD recorded in stereo, and use stereo headphones (not supplied).

2 Insert an MD.

2 Insert an MD with the label side facing up, and press the lid down to close.

3 Play an MD.

Speaker (monaural) 2 (headphones) VOL (volume) 2 Turn VOL to adjust the volume. To stop play, press p(stop).

( (play) 1 Press (.

The recorder starts to play the first track. The recorder automatically switches to play in stereo or monaural according to the recorded sound.
Press P Press P again to resume play. = once
To listen in stereo sound
Connect stereo headphones (not supplied) to the 2 jack.
If the play does not start
Make sure the recorder is not locked (page 21).
Find the beginning of the current track Find the beginning of the next track Go backwards while playing* Go forward while playing* Remove the MD

+ once

You can play an MD with new alkaline batteries for 6 hours.
keep pressing = keep pressing + p and open the lid**
Display window while playing back
Track number or track name* Elapsed time of the track being played
* To go backward or forward quickly
without listening, press P and keep pressing = or +. ** Once you open the lid, the point to start play will change to the beginning of the first track.
* Appears only with MDs that have been

electronically labeled.

zVarious ways of recording Dictating

(Digital VOR function)

You can dictate easily using the digital VOR (Voice Operated Recording) function. You do not have to press any buttons to suspend recording while dictating. Microphone VOR indicator VOR ON/OFF p (stop)

To stop dictating

Press p. The recorder will switch back to normal recording when you record next time.
You cannot record with the built-in microphone while an external microphone is connected to the MIC PLUG IN POWER jack. This recorder's VOR function is designed for dictation, not for recording interviews or conferences. As long as VOR is on, the batteries are used even while nothing is being recorded (the VOR indicator flashes).

Insert a recordable MD and start recording. To record, see "Recording an MD right away!" (page 6). Press VOR ON/OFF. The VOR indicator lights up. Speak into the microphone. Hold the recorder and keep it close to your mouth around 4 inches (10 cm) from your mouth. The VOR indicator lights up while your voice is recorded, and flashes while nothing is recorded.
To release the digital VOR function
Press VOR ON/OFF. The VOR indicator goes off, and the recorder switches to normal recording.
Recording in stereo with an external microphone
You can record in stereo sound using ECM-909A, ECM-727P, etc. (not supplied). You can record for up to 74 minutes on 74-minute MD or 60 minutes on 60minute MD. Stereo microphone
To record in monaural for double the normal recording time of an MD
Set MONO/STEREO to MONO. The recording time will be double the normal.
To record with an external monaural microphone
Use a monaural microphone ECM-T140, ECM-T110, etc. (not supplied), and set MONO/STEREO to MONO.
Various ways of recording
to MIC PLUG IN POWER MONO (monaural)/ STEREO
The MONO/STEREO switch functions only when an external microphone is connected to the MIC PLUG IN POWER jack. If you connect a stereo microphone and set MONO/STEREO to MONO, the mixed sound from both the right and left channels will be recorded. If you connect a monaural microphone and set MONO/STEREO to STEREO, only the left channel sound of the source will be recorded. The MDs recorded in monaural sound can be played back only with an MD player/recorder that has the monaural playing function.
Connect the microphone to the MIC PLUG IN POWER jack. Set MONO/STEREO to STEREO. Insert a recordable MD and start recording. To record, see "Recording an MD right away!" (page 6). While recording, "STEREO" appears in the display.

To stop recording

Press p.
Recording from other equipment
Use a line cable (RK-G134 or RK-G128, not supplied) to connect the recorder to the source equipment. Portable CD player, portable MD player, etc. to 2 or PHONES Stereo-mini plug RK-G134 (not supplied) to MIC PLUG IN POWER

Connect the MIC PLUG IN POWER jack of the recorder to the source equipment with a line cable. Set MONO/STEREO to STEREO. Insert a recordable MD and start recording. To record, see "Recording an MD right away!" (page 6). While recording, "STEREO" appears in the display. Play the sound source.
To record from a monaural player
Connect the RK-G135, RK-G64, etc. (not supplied) to the earphone jack of the source equipment, and set MONO/ STEREO to MONO.
MONO (monaural)/ STEREO Cassette-corder, CD player, MD player, etc. 2 phono plugs R (red) to LINE OUT or REC OUT L (white)
If you connect a monaural equipment and set MONO/STEREO to STEREO, only the left channel sound of the source will be recorded. The MDs recorded in monaural sound can be played back only with an MD player/recorder that has the monaural playing function.
RK-G128 (not supplied) to MIC PLUG IN POWER

MONO (monaural)/ STEREO

Track marking while recording
Track marking to divide a recording
Track marking essentially adds tracks while recording and enables you to quickly find and play from the marked position. The track marking feature is useful particularly when recording a discussion, an interview, etc. You can add track marks with the recorder or the remote controller. To use the remote controller, connect it to the TRACK MARK (REC)/PAUSE jack. Speaker A n B n A n C 4
While recording, press TRACK MARK on the recorder or the remote controller. A track mark is added and the track number will increase by one. The record indicator flashes and "MARK ON" appears in the display. Elapsed time of the track being played

Track number

To add track marks after recording
See Track marking a recording (page 23).
Add track marks when the speaker changes.

To erase track marks

See Erasing a track mark (page 24).

To find track marks

While playing, press = or + slightly.
TRACK MARK to TRACK MARK (REC)/PAUSE

Continue to next page m

TRACK MARK
Track marking important points
While you record a discussion or an interview, you can add not only regular track marks but special track marks. Special track marks can be found independently of the regular track marks during playback. You can add special track marks only with the remote controller while recording. 8

Special track marks cannot be added after recording
You can add special track marks only while recording.
To erase special track marks
See "Erasing a track mark" (page 24).
To find special track marks while playing
While pressing VOR ON/OFF, press = or + slightly. The special track mark indication "TT" appears following the track number. Each time you press =, you can find the previous special track mark. Each time you press +, you can find the succeeding track mark.
Regular Special track marks track marks While recording, press TRACK MARK on the remote controller twice. A special track mark is added and the track number will increase by one. The record indicator flashes and "!MARK ON!" appears in the display. Elapsed time of the track Track number being played

Tips on track marks

Total number of track marks
You can record up to 254 track marks in total of the two kinds regular track marks to divide a recording and special track marks on an MD.
Regular and special track marks are recorded in the same way as the track marks on music discs.
The two kinds of track marks recorded with this recorder can be used for playback operation in the same way as the track marks recorded on the beginning of each music track on a music disc.
To add a special track mark, press TRACK MARK twice within one second. If you press the button secondly after more than one second passes, two regular track marks will be recorded.

Tips on recording

To monitor the sound being recorded
Connect headphones (not supplied) to the 2 jack and adjust the volume by turning VOL. Sound levels are copied onto the MD automatically and independently of the volume for monitoring.

To protect a recorded MD

To record-protect an MD, slide open the tab at the side of the MD. In this position, the MD cannot be recorded. To record again, slide the tab back so the tab is visible. Rear of an MD
To know the recording condition
The record indicator flashes according to the recording condition. Record-protect

Recording condition

Record indicator
While recording Flashes according to the loudness of the source (voice mirror). Recording standby Recording with less than 3 minutes recording time available Flashes. Slowly flashes. Continue to next page m

To know the remaining time, etc.

Display window

While in stop mode Press DISPLAY while the recorder is in stop mode. Each time you press the button, the display changes as follows. Track number
DISPLAY While recording Press DISPLAY while recording. Each time you press the button, the display changes as follows. Track number
Elapsed time of the track being recorded. Track number

REC REMAIN

Remaining time after the current location. Remaining number of tracks*

REMAIN

Remaining time of the recording. Current date**
Remaining time for recording. Current date*

DATE AM

Current time**

Current time*

*Appears only when the clock is set.
* A disc name appears only with MDs that have been electronically labeled. ** Appears only when the clock is set.
Setting the clock to stamp the recorded time
To stamp the date and time on the MD when you record, you first need to set the clock. When you use the recorder for the first time or after a long period of disuse, charge the built-in battery for the clock after setting the clock (page 18). = +
Press (. The year is set and the digit of the month flashes.
Repeat steps 3 and 4 to enter the current month, date, hour, and minute. When you press ( to set the minute, the clock starts operating.
CLOCK SET ( (on the bottom)
Battery compartment (on the bottom)
If you make a mistake while setting the clock
Press p, and set the clock again from step 2. You can skip a step by pressing (.
Connect the power source. Install three size AA (LR6) batteries. Press CLOCK SET on the bottom of the recorder. Use a pointed object. The digits of the year flash. Year, month, and date

On the clock display

To display the current time When the recorder is not operating or while recording, press DISPLAY repeatedly until the current time appears in the display. The time indication disappears after 10 seconds. To display the time in the 24-hour system While setting the clock, press DISPLAY. To display the time in the 12-hour system, press DISPLAY again.

Current time

Enter the current year by pressing = or +. To change the digits rapidly, keep pressing = or +.
Charging the built-in battery for the clock
After setting the clock, leave the recorder with the dry batteries installed for about 2 hours to charge the built-in battery for the clock. You can use the recorder while charging. Once charged, the built-in battery should last about a month without connecting to any of the power sources. The recorder will automatically charge the built-in battery while connected to dry batteries, AC power, or a rechargeable battery.

zVarious ways of playback Listening at a fast speed
You can reduce the listening time by using the fast playback function. The playback speed can be set to 1.6 or 2.2 times as fast as the normal playback. FAST PLAY
Playing tracks repeatedly
You can play tracks repeatedly in three ways all repeat, single repeat, and shuffle repeat. PLAY MODE
Various ways of recording Various ways of playback
Press FAST PLAY. "FAST" appears in the display, and fast playback starts at a speed of 1.6 times normal. To change the speed to 2.2 times, press FAST PLAY again.
Press PLAY MODE while the recorder is playing an MD. Each time you press PLAY MODE, the play mode indication changes as shown in the next page.

Fast playback indication

To suspend fast playback

Press P.

Press = or + during fast playback.
To switch to normal playback
Press (. To return to fast playback, press FAST PLAY.

Play mode indication

Track number or track name*

Tips on playback

To know the time and track name
You can see in the display window the name, number, remaining time, and recorded time of the track being played. Display window

MONO SHUF

* Appears only with MDs that have been electronically labeled.

(none) (normal play)

A whole disc (all the tracks) is played once.

. f (all repeat)

A whole disc (all the tracks) is played repeatedly.

. f1 (single repeat)

A single track is played repeatedly.
DISPLAY Press DISPLAY while the recorder is playing an MD. Each time you press DISPLAY, the display changes as shown on the next page.

. fSHUF (shuffle repeat)

All the tracks are played repeatedly in random order.

Track number or name*

To lock the controls (Hold function)
To prevent the buttons from being accidentally operated while carrying the recorder, use this function.
Elapsed time of the track being played

Various ways of playback

Remaining time of the current track. Remaining number of tracks
Slide HOLD in the direction of the c. The controls on the recorder are locked.
Remaining time of the recording. Recorded date**

REC DATE AM

Recorded time**
* Appears only with MDs that have been electronically labeled. ** The indications show the date and time when you started recording or added the track mark. If you record without setting the clock or play an MD that has no recorded date, "- - y - - m - - d" and "- - : - -" appear.

Listening with other equipment
Connect the 2 jack of the recorder to a tape player or an amplifier with a line cable (RK-G134, or RK-G129, not supplied). You can listen to an MD with your stereo system or record on a cassette tape, etc. Stereo tape recorder, portable MD recorder, etc. to MIC Stereomini plug RK-G134 (not supplied)
Stereo system, cassette-corder, etc. to LINE IN 2 phono plugs R (red) L (white)

RK-G129 (not supplied)

to 2 (headphones)
Adjust the volume around "6". to 2 (headphones) To listen with a monaural player
Connect the RK-G135 line cable (not supplied) to the MIC jack of the source equipment.
Adjust the volume around "6".

zEditing recorded tracks

You can edit your recordings by adding or erasing track marks, or erasing tracks. Premastered MDs cannot be edited.
While the recorder is playing an MD, press TRACK MARK on the recorder at the point you want to mark. A track mark is added and the track number will increase by one. Elapsed time of the track Track number being played
Track marking a recording
You can add track marks so that you can quickly find and play from the marked position. The track numbers will increase as follows. 1. Track marking Note 5
Various ways of playback Editing recorded tracks
TRACK MARK on the remote controller does not function during playback.
Track numbers increase To add track marks while recording
See "Track marking while recording" (page 13).

Notes TRACK MARK

When you press p after adding track marks, "Toc Edit" flashes and the recorder starts writing the new data to the MD. Do not move or jog the recorder while "Toc Edit" is flashing in the display. You cannot add track marks on an MD that is record-protected. Before adding track marks, close the tab on the side of the MD.
SONY MZ-B3 (E) 3-798-373-22(1)

Erasing a track mark

You can erase a track mark to combine the tracks before and after the track mark. You can erase regular track marks and special track marks in the same way. The track numbers will change as follows. 1. 3 4
Press TRACK MARK on the recorder to erase the mark. The track mark is erased and the two tracks are combined.
4 Erase a track mark To erase other track marks 2 3

Repeat steps 2 and 3.

Track numbers decrease TRACK MARK

Battery lifea)

Batteries

RecordPlaybackc) ingb)

Size AA (LR6) Approx. Approx. alkaline 3 hours 6 hours batteries Lithium ion rechargeable battery (LIP-12) Approx. Approx. 2 hours 3 hours
Size AA (LR6) Approx. Approx. 6 hours 10 hours alkaline batteries and a lithium ion rechargeable battery (LIP-12)
The battery life may be shorter due to operating conditions and the temperature of the location. When you record, use new dry batteries or a fully charged rechargeable battery. When played using the built-in speaker
zAdditional information Precautions

On safety

Do not put any foreign objects in the DC IN 4.5 V jack. While carrying the recorder Keep personal credit cards using magnetic coding or spring-wound watches, etc., away from the recorder to prevent possible damage from the magnet used for the speaker.

On power sources

Use three size AA (LR6) batteries, the house current, or a lithium ion rechargeable battery. For use in your house: Use the ACE45HG AC power adaptor (not supplied). Do not use any other AC power adaptor since it may cause the recorder to malfunction. Polarity of the plug The recorder is not disconnected from the AC power source (mains) as long as it is connected to the wall outlet, even if the recorder itself has been turned off. If you are not going to use this recorder for a long time, be sure to disconnect the power supply (dry batteries, AC power adaptor, or a rechargeable battery). To remove the AC power adaptor from the wall outlet, grasp the adaptor plug itself; never pull the cord.

On the headphones

Road safety Do not use headphones while driving, cycling, or operating any motorized vehicle. It may create a traffic hazard and is illegal in many areas. It can also be potentially dangerous to play your recorder at high volume while walking, especially at pedestrian crossings. You should exercise extreme caution or discontinue use in potentially hazardous situations. Preventing hearing damage Avoid using headphones at high volume. Hearing experts advise against continuous, loud and extended play. If you experience a ringing in your ears, reduce the volume or discontinue use. Caring for others Keep the volume at a moderate level. This will allow you to hear outside sounds and to be considerate of the people around you.
Power sources Additional information

On heat build-up

Heat may build up in the recorder if it is used for an extended period of time. In this case, leave the recorder to cool down.
On the MiniDisc cartridge
Do not break open the shutter. Do not place the cartridge where it will be subject to light, temperature, moisture or dust.

On installation

Never use the recorder where it will be subjected to extremes of light, temperature, moisture or vibration. Never wrap the recorder in anything when it is being used with the AC power adaptor. Heat buildup in the recorder may cause malfunction or injury.

On cleaning

Clean the recorder casing with a soft cloth slightly moistened with water or a mild detergent solution. Do not use any type of abrasive pad, scouring powder or solvent such as alcohol or benzene as it may mar the finish of the casing. Wipe the disc cartridge with a dry cloth to remove dirt.
Dust on the lens may prevent the unit from operating properly. Be sure to close the disc compartment lid after inserting and ejecting an MD.
DISPOSAL OF MANGANESE DIOXIDE LITHIUM BATTERY AND LITHIUM ION BATTERY. MANGANESE DIOXIDE LITHIUM BATTERY AND LITHIUM ION BATTERY. DISPOSE OF PROPERLY. You can return your unwanted manganese dioxide lithium batteries and lithium ion batteries to your nearest Sony Service Center. Note: In some areas the disposal of lithium ion batteries and manganese dioxide lithium batteries in household or business trash may be prohibited. For the Sony Service Center nearest you call 1-800-222-SONY (United States only) Caution: Do not handle damaged or leaking lithium ion battery and manganese dioxide lithium battery.

Note on mechanical noise

The recorder gives out mechanical noise while operating, which is caused by the power-saving system of the recorder and it is not a trouble.

Notes on recording

Mechanical shock or vibration Do not subject the recorder to strong mechanical shock or continuous vibration while recording. The sound may be skipped or recording may stop. After you stop recording, "Toc Edit" flashes while the data of the recording is being stored. Do not move or jog the recorder while the indication is flashing in the display. Noise while recording When you record with the built-in microphone or an external microphone, the sound is sent as an analog signal, converted to a digital signal, and recorded on an MD. During these processes, noise may be recorded. And when you record with the built-in microphone in a quiet place, mechanical noise of the recorder may be recorded. These are not problems. You cannot record using a timer. If you press the rREC button with the power off or not connected, the button will stay pressed down. But as soon as the power is turned on, the button will be released automatically. For this reason, you cannot record using a timer.

To remove the manganese dioxide lithium battery
On disposal of this product, remove the manganese dioxide lithium battery in the battery compartment and treat it as mentioned above.
Remove the black sheet with a pointed object.

Remove the battery.

Do not remove the black sheet unless you are disposing of this product, or it may not work properly.
If you have any questions or problems concerning your recorder, please consult your nearest Sony dealer.

Additional information

Troubleshooting
Should any problem persist after you have made these checks, consult your nearest Sony dealer.
Symptom The recorder does not work or works poorly.
Cause/Solution Moisture has condensed inside the recorder. b Take the MD out and leave the recorder in a warm place for several hours until the moisture evaporates. The dry batteries or rechargeble battery are weak (b "LOW BATT" flashes). b Replace the dry batteries or recharge the battery (page 6 or 27). The dry batteries have been installed incorrectly. b Install the batteries correctly (page 6). You pressed a button while the disc indication was rotating quickly. b Wait until the indication rotates slowly. The AC adaptor was unplugged during recording or a power outage occurred. Audio sources may not be securely connected. b Disconnect the audio sources once and connect them again (pages 12, 22). While operating, the recorder received a mechanical shock, too much static, abnormal power voltage caused by lightning, etc. b Restart the operation as follows: 1 Disconnect all the power sources. 2 Leave the recorder for about 30 seconds. 3 Connect the power source.
No sound comes through the speaker. An MD is not played from the first track.
Volume is too low. b Adjust the volume by turning VOL. Disc playing stopped before it came to the last track. b Press = repeatedly or open and close the lid once to go back to the beginning of the disc, and restart playing after checking the track number in the display. The recorder is placed where it receives continuous vibration. b Put the recorder on stable place. A very short track may cause sound to skip.

Playback sound skips.

Symptom Sound has a lot of static. The REC button stays pressed down.
Cause/Solution Strong magnetism from a television or such device is interfering with operation. b Move away from the source of strong magnetism. You pressed the REC button while the recorder was not connected to the power source. b Install dry batteries or a rechargeable battery. Or connect to house current with the AC power adaptor (page 6 or 27). You tried to erase the track marks after pressing = or + and pressing P. b Press P before pressing = or +, then erase the track marks. The built-in battery for a clock is weak. b Connect the power source to charge the built-in battery. After charging, set the clock again. Note that the clock normally loses about 2 minutes per month (page 18).