Pioneer PDP-4214HD - Page 70

CHANNEL INSPECTION
If channel locking fails even though there is no problems with the system, check
the Interface between Tuner, LGDT3303 and CPU.
Channel Inspection
No Channel Locking with No Problems with Power/CPU
Preliminary Checkpoints
Check the LGDT3303
input voltage
- LDGT3303 Input Power
* +3.3V
Pin21, 35, 61, 93
* +1.8V
PIN16, 19, 32, 42, 47, 55, 63,
68, 74, 81, 85, 89, 100
Channel locking failure
Check other related
part
After the basic inspection, check the
path between U501 and LGDT3303
(Incorrect insertion, poor soldering,
short circuits, damage, etc)
NG
OK
Check the LGDT3303 input
(Reset) = high
- LDGT3303 PIN26
* low : reset on
* high : reset release
Check the path between
CPU and LGDT3303 (Incorrect
insertion, poor soldering, short
circuits, damage, etc.)
NG
OK
Check the LGDT3303
input clock
- LGDT3303 Pin 79, 80
* 25MHz clock
Check the path between
LGDT3303 and X-Tal (Incorrect
insertion, poor soldering, short
circuits, damage, etc.)
NG
OK
Check the 12C control
- 12C CLOCK [PIN48]
- 12C DATA[PIN49]
Check the path between
devices the LGDT3303 and EEPROM
Also, check Incorrect insertion, poor
soldering, short circuits, damage, etc.)
NG
Useful Tips
1. Check the power byU532 are properly provided to the U531.
2. Check the 12C interface between tuner and 10046. If no problem, inspect along the tuner output path to TDA10046.
Whether the components of R, L, C's soldering status.
3. If no problem, replace the Tuner.
4. If the problems are founded by CPU, replace the CPU board and also download SN.
Waveform 14
70