Panasonic EB-X700, Service Manual

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FAULT FINDING
Provisional Issue Section 8 PMCE041201C8
Revision 1 – 6 – Service Manual
8.2.2 Partial Power-on Fault Analysis
On the X700 handset, a partial power-on fault is defined as the major hardware components or main software code
functioning correctly with no failures on Fault Codes A to E. However, the handset fails to power up completely because of
some other hardware or software failure.
The possible partial power on fault can be divided to two categories as follows:
• S-GOLD controlled hardware circuits failed to completely power up or run up from initialization.
• OMAP controlled hardware circuits failed to completely power up or run up from initialization.
Use the two Fault Code tables below.are recommended to follow through for possible Fault Finding. The Fault Codes should
be debugged sequentially.
8.2.3 GOLD Controlled Hardware Fault from Initialization
Fault
Code
Symptoms Root Cause Debugging Action
A No 26MHz at C504 Bad Y500 or no VRF1
voltage Check pin3 of Y500, replace Y500 if there is
no 26MHz clock.
Check VRF1/TP335 with Ohm meter, if
<100 Ohm, debug the RF section; Otherwise,
replace U304, S/M power.
B No related default voltage
supply to S-GOLD. Battery input circuitry to
the phone is broken, or
Bad S/M power IC. Check VDBB/TP324 (1.8V), VINT/TP328
(2.7V), VLBB2/TP326 (1.5V); Check VBATT
input paths to the S/M power. If OK, replace
S/M power IC U304.
C RESET-N/TP323 is not
logic high Bad S/M power IC or
soldering problem. Check TP323 and R350, replace U304 if logic
low at both end of R350.
D S-GOLD is not working. Bad S-GOLD IC or
soldering problem. Replace S-GOLD IC U100.
E Failed to re-load the
software to S-GOLD from
either inner boot loader or
flash boot loader. Corrupted boot loader
inside S-GOLD IC. Replace S-GOLD IC U100 and reload the S-
GOLD software.
Fault
Code
Symptoms Root Cause Debugging Action
F S-GOLD does not supply
13 MHz / TP219 to
OMAP or / and release
AP-RST/TP109 Corrupted S-GOLD code;
or unstable VRF1 supply
causes 26MHz clock
unstable. Re-load the latest S-GOLD code;
Check VRF1 / TP335 with Ohm
meter. If < 100
Ω
, debug the RF
section. Check pin 2 of U204 for
13MHz clock;
If problem persists, replace S/M
power IC U304
G Keypad backlighting is
not turned on, or turns on
much later than normal. Corrupted S-GOLD code;
or unstable VRF1 supply
causes 26MHz clock
instablity; or bad I2C link
from SGOLD to S/M
power IC. Check VRF1/TP335 with Ohm meter,
if <100
Ohm debug the RF section;
Re-load the latest S-GOLD code;
Check +15V/TP309, if present I2C
link is OK;
If problem persists, replace S/M
power IC U304
H D15V/TP309
is not turned on. Corrupted SGOLD code;
or
unstable VRF1 supply
causes 26MHz clock
instablity; or bad I2C link
from S-GOLD to
Companion IC Check VRF1/TP335 with Ohm meter,
if < 100
Ω
, debug the RF section;
Re-load the latest S-GOLD code;
If keypad backlighting is on, I2C link is
OK;
Check D300 with an Ohm meter;
Replace Q300; If problem persists,
replace Companion IC U300.