Pioneer VSX-45TX Service Manual page 140

1
Flow of USB Input Data
A
USB
terminal
Personal Computer
Music playback
(A music file of MP3, etc.)
B
About PCM2902EG
• With codec of USB BUS POWERED, power is supplied from Vbus of USB, and work. (work with a power supply of VSX-45TX irrelatively.)
• Be USB codec, but analog I/O and digital (SPDIF) input are not using in VSX-45TX.
• When only connects to PC and receiver (VSX-45TX) is turned on, the output of TC7SET08F outputs.
Help of Non-failure Decision
Symptom when a sound is not output
(Symptom is different by each OS)
• Confirm a driver whether PC is recognizing it. (With a device
manager).
• Is a switch of sound sourse performed properly? (Control Panel,
C
Sound or Multimedia)
• Is volume control of PC adjusted?
• How is other PC?
• In the state that does not change PC setting, is sound output in
other VSX-45TX?
• When uses CD-ROM and playback a music CD, and a sound is
not output, is digital playback of CD-ROM checked?
When contain noise
• There is a bug in early USB AUDIO driver of WINDOWS XP, and
contain noise once for several minutes. (Correspond with
WINDOWS UPDATE.)
• An affinity problem with chip set
• Adaptation problem with chip set (refer to next item)
D
• Performance issue of PC. (Release resident software as
measures.)
• Noise when using the other software during music playback.
(Do not guarantee or do not use the other software)
• Do contain the same noise even if changes the PC?
Reference
Confirmation item of the USB part with Function checker.
Supply a power supply (+5V: pin 3, GND: pin 4) of IC1681
(PCM2902EG), and connect D+ (pin1) to GND.
Confirm that X1681 (ASS7047) starts oscillating.
Support OS
Windows 98 / 98SE / ME
E
Windows 2000 Professional
Windows XP Home / Professional
F
140
1
2
VSX-45TX USB block
USB
USB
input
cable
USB AUDIO data
VSX-45TX
2
3
USB CODEC
PCM2902EG
TC7SET08F
D +
Dout
D –
SPDIF
Vbus
data
GND
For DIR input
protection
12MHz
Adaptation Problem with Chip Set
PCM2902EG caution of operation
Operating environment and findings of PCM2902EG
Evaluation PC: Libretto PAL2060 TNML made by Toshiba
(1) CPU: Crusoe 600MHz made by Transmeta
Use chip set: Transmeta N/B (North Bridge)
M1533 (South Bridge) made by ALi
OS: Windows ME
(2) CPU: Cerelon 566MHz made by Intel
Use chip set: Aladdin Pro 5 (North Bridge) and M1533 (South
Bridge) made by ALi
OS: Windows ME
(3) CPU: K6-2 400MHz made by AMD
Use chip set: Aladdin 5 (North Bridge) and M1543 (South
Bridge) made by ALi
OS: Windows ME
When contain noise by a problem of the chip set side, there is a
problem in the PC side because even other USB audio equipment
contains noise.
Therefore, do not recommend use in the condition and environment
as mentioned above.
3
4
DSP block
IC201
DIR
SPDIF
AK4114VQ
data
4