Projection display Purchased two units,both had display segment problems.On one, all segments were lit all of the time-had a display with four 8's. On the second unit, only several of the segments in each number were active-no full number would light. The clock worked fine. I gave up. Back it goes-again!!! unhappy

there are four diodes for the display and the other lights on the face . take off the bottom cover ,look for the they should be together,replace all four. that should do it

STEP ONE (PRELIMINARY): With the key in the ignition, turn the ignition to ACC (accessory power) or this can be done while the vehicle is running. If unit remains off, proceed to the next step, but if unit is already powered on, power it down by pressing [Source] until it goes off. (Then, proceed to the next step.)

STEP TWO: Press MULT-CONTROL & hold until CLOCK SET displays. (To cancel at any time, press [Band/ESC]. Press [Back] to return to previous display.)

STEP THREE: Press MULTI-CONTROL to select the desired segment of the clock display to set. Each time MULTI-CONTROL is pressed, it selects (blinks) one clock display segment: Hour - Minute.

STEP FOUR: Turn (or push) MULTI-CONTROL (up/down) to change the clock display segment setting.

According to the manual for this specific unit, the steps to set the clock are as follows (with minor editing for clarity):

MULTI-CONTROL Being the round knob on the radio.

1 Press SOURCE and hold until the unit

turns off.

2 Press the MULTI-CONTROL and hold until

CLOCK SET appears in the display.

3 Use the MULTI-CONTROL to select

CLOCK SET in the initial setting menu.

4 Press MULTI-CONTROL to display the

setting mode.

5 Press MULTI-CONTROL to select the segment

of the clock display you wish to set.

Each time you press MULTI-CONTROL, one

segment of the clock display is selected.

As you select segments of the clock display,

the selected segment blinks.

6 Turn the MULTI-CONTROL to set the clock.

You can also perform the same operations by
pushing MULTI-CONTROL up or down.

Just went to their site and this is what it said:

This may simply be a matter of misinterpreting the low-battery indicator. We use two different types of battery indicators:

1. Battery Level Indicator: This battery indicator is always visible, and has several segments. When all the segments are lit, the batteries are full. When only the last segment is lit, the batteries are almost exhausted.
   
2. Low Battery Indicator: This type is usually NOT visible. It only appears when the batteries are low, at which time it flashes on the display to warn you of a low battery condition.

Please note that when you turn on your radio it first performs a display test. Everything on the display will light up for a few seconds, including the Low Battery Indicator. This does not mean that the batteries are low. After a few seconds the display test will end, at which time the Low Battery Indicator should go away.

If it is a later model with the black amplifier there is a red digit 8 lit up on the amp. When the amp is unmuted only the bottom segment is lit. If the top and bottom segment are lit the amp is not being unmuted.

Adjusting initial settings

1 Press SOURCE and hold until the unit turns off.

2 Press MULTI-CONTROL and hold until CLOCK SET appears in the display.

3 Turn MULTI-CONTROL to select CLOCK SET (clock)

Setting the clock
Use these instructions to set the clock.
1 Use MULTI-CONTROL to select CLOCK SET.

2 Press MULTI-CONTROL to display the setting mode.# Press BACK to return to the previous display.

3 Press MULTI-CONTROL to select the segment of the clock display you wish to set.
Each time you press MULTI-CONTROL, one segment of the clock display is selected.

As you select segments of the clock display, the selected segment blinks.

4 Turn MULTI-CONTROL to put a clock right.

# You can also perform the same operations by pushing MULTI-CONTROL up or down

Press SOURCE and hold until your head unit turns off. Press MULTI-CONTROL and hold until Clock Set appears in the display. Press MULTI-CONTROL to display the setting mode. Press MULTI-CONTROL to select the segment of the clock display you wish to set. Each time you press MULTI-CONTROL, one segment of the clock display is selected (Hour-Minute) As you select each segment of the clock display, the selected segment blinks. Turn MULTI-CONTROL knob to adjust blinking segment.
Reference page 29 in your instruction manual.

http://www.pioneerelectronics.com/pio/pe/images/portal/cit_11221/429287552DEHP7900BTOperationManual0328.pdf

Your Owners manual

Setting the date
The calender display adjusted in this mode appears
when the telephone source is selected
or sources and the feature demo are off.
1 Use MULTI-CONTROL to select
Calendar.
2 Push MULTI-CONTROL left or right to
select the segment of the calendar display
you wish to set.
Pushing MULTI-CONTROL left or right will select
one segment of the calendar display:
Day—Month—Year
As you select segments of the calendar display
the segment selected will blink.
3 Push MULTI-CONTROL up or down to
set the date.

Setting the clock
Use these instructions to set the clock.
1 Use MULTI-CONTROL to select Clock.
2 Push MULTI-CONTROL left or right to
select the segment of the clock display you
wish to set.
Pushing MULTI-CONTROL left or right will select
one segment of the clock display:
Hour—Minute
As you select segments of the clock display
the segment selected will blink.
3 Push MULTI-CONTROL up or down to
put a clock right.
Note
You can match the clock to a time signal by
pressing MULTI-CONTROL.
! If the minute is 00 to 29, the minutes are
rounded down. (e.g., 10:18 becomes 10:00.)
! If the minute is 30 to 59, the minutes are
rounded up. (e.g., 10:36 becomes 11:00.)