Sony KV-28DS20U Service Manual page 7

Protection Error (Error 2):
Once every main loop (approximately 200ms OSD mode, 50ms text or menu mode), the micro checks the protection pin (pin 66). If the protection
pin is high 6 successive times, a protection error is diagnosed. The protection pin is not checked during the first 3 - 4 seconds after AC on.
If this error is diagnosed, the respective NVM register will be updated and the set goes straight into diagnostic standby with 2 flashes - no reset is
attempted.
AKB Error (Error 5):
Once every main loop the micro checks the AKB stability by reading the IKR return from the Jungle IC. IKR=1 means that the AKB is stable,
IKR=0 means that the AKB is unstable. If the AKB status is unstable for 10 seconds, an AKB error is diagnosed. AKB stability is not checked
during the first 20 seconds after AC switch on.
If this error is diagnosed, the respective NVM register will be updated and the response LED will flash 5 times continually, but the set will not go
into standby mode. If the AKB status becomes stable, and remains stable for 10 seconds, the LED will stop flashing.
0
IKR
Return
A.
B.
C.
D.
E.
F.
Startup Diagnostic Errors (Errors 6-18, 27, 29-32):
NVM
6
7
8
9
10
11
12
13
14
16
18
27
29
30
31
32
If any of these errors are detected, the respective NVM register will be incremented. The software will then carry on with the power up sequence.
10 20 30 40
A B C
IKR Return first goes high after 12 seconds.
Micro begins checking IKR Return status 20 seconds after power on.
Micro detects IKR return = 0.
Micro detects that IKR has been 0 for 10 seconds; NVM counter is incremented and the LED
starts flashing (flashes 5 times, off for 2 seconds, flashes 5 times, etc.
Micro detects that IKR=1; LED continues to flash.
Micro detects that IKR has been high for 10 seconds; LED stops flashing.
Error Description
SCL pin low
SDA pin low
Both SCL and the SDA pins are low
No acknowledge from the jungle (CXA2076)
No acknowledge from the video switch (CXA2040)
No acknowledge from the tuner
No acknowledge from the MSP
No acknowledge from the NVM
No acknowledge from the CXA2089 video switch (DS20 & DX20)
No acknowledge from the CXA1875 video Port Expander (DS20 & DX20)
No acknowledge from the Dynamic Convergence (CXA8070)
M3L_TXD pin low after Compact Text RAM test.
M3L_TXD pin low
M3L_RXD pin low
M3LEN pin low
Compact Text RAM test fail
Time / seconds
50 60
D
7
70 80 90 100
E F