Power Block Troubleshooting - Sony Mavica MVC-FD85 Training Manual

Power Block Troubleshooting

No Power ON
1. No response to the power ON switch with any power source.
An open fuse, bad power switch or a defect on the FU board can
cause the problem. Before opening the unit, connect the AC adapter
and power up the unit using the RM-95 Remote Commander. You
can use the RM-95 to force the Mavica ON in the Play, Still or Movie
Modes. See "Using the RM-95..." (table of contents) for the proce-
dure. If you can power the Mavica ON with the RM-95, the normal
power ON button input signal is not reaching IC404/pin 14 on the FC
board.
If the Mavica does not power ON with the RM-95, open the rear panel
and check the fuses by looking for input voltage on the top right con-
nector CN001/pins 1-8 of the FC-72 board (service manual - frame
diagram section 4-1). Pin 1 is on the right.
2. Mavica only works with the AC adapter - not with a good InfoLithium
battery.
Either fuse F004 is open, Q001 / Q004 are bad or the Fast Charge
ON signal from the FC-72 board is missing. Check F004 by looking
for battery voltage at the top of the FC-72 board at CN001/pin 8. Next
slide the power ON switch and look for 3.2Vdc at the Fast Charge ON
signal output CN002/pin 3. If this voltage is missing, the problem is
on the FC-72 board. If this voltage is present, replace Q001 and
Q004 on the FU board.
3. Camera Shuts Down after Powering On.
The main microprocessor HI Control IC404 needs to be reset or the
battery down information in one of the EEPROMs is corrupt, causing
premature shutdown.
Reset the microprocessor by removing the back panel and releasing
its flex cable from the main FC-72 board. Reconnect the flex cable
after four seconds. Unplugging the cable disconnects the recharge-
able coin battery on the rear panel from the micro on the main board
so the micro can fully reset when full power is next applied.
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Perform the battery down adjustment as outlined in both this training
manual and the service manual. The camera does not have to be
taken apart, but a power supply, DVM, the RM-95 adjustment tool,
and a special power cord are needed.
NO Battery Charging.
1. AC adapter and Battery are plugged in but the amber charge light
does not come on.
One of the power sources is missing or is not detected by IC404 on
the FC-72 board. First make sure the camera operates with AC and
battery power individually. That checks the fuses at the hard to get to
FU140/146 board. If one of these power sources does not work, you
can measure the AC and battery sensing voltage input to IC404 at the
top of the FC-72 board, CN001 connector, pins 1 (AC) and 8 (battery).
If the main board input voltages at CN001/pins 1 and 8 are present,
unplug the battery and look for a 1-second pulse output from the FC-
72 main board at CN002/pin 4. This pulse is amplified by Q003 on the
FU board and should appear at its collector as an 8Vp-p signal unless
Q003 or charge inhibit Q005 is shorted.
This signal is amplified again and can be seen at the battery jack
J901/pin 1 where 8.4Vdc is used to test charge the battery (when
inserted). From this point it is up to the micro in the battery to send
charge needed or no charge needed data to IC404. If no charge is
needed or the battery voltage is too low (defective), IC404 will not turn
on the charge light.
No battery charging could theoretically occur if the battery jack J901
switch is open. The additional symptom is no battery time display.
2. The amber charge light comes ON but the battery does not charge.
Just because the amber charge light comes ON does not mean the
charge signal from IC404 is going to completion. The charge light
signal and charge signal come from different IC404 ports.
Check the charge signal (3.2Vdc) from the top of the FC-72 board at
CN002/pin 3. If this charge signal is present, the main board is OK.
Suspect Q004, Q001 or the battery itself.