Epson DFX-8500 Service Manual page 70

DFX-8500
‰Protection circuits :
These +37VDC line blocks perform voltage control, and they have over-current limiting and over voltage
protection circuits for each.
‰Control and status signals :
The PSB//PSE board receives two control signal from the C204 MAIN board and outputs two status signals
to the MAIN board. Refer to Table 2-3 for the each signal and the printer status relationship.
‰Fatal error recovery :
When the printer detects the fatal error, the PSB/PSE board cannot recover for APPROX.10 minutes by the
DRERR signal of the C204 MAIN board, after the power is turned off. Therefore, you must wait more than 10
minutes turn the power on again.
Signal
/PD
(Power Down)
DRERR
(Head coil/driver error)
/SD
(Source Down)
CL
(Current Limit*4)
*1): From the view of the PSB/PSE board.
*2): VP1-GP1 and VP2-GP2
*3): VP3-GP3 and +5V-GL
*4): Due to high duty printing
2-16
Table 2-4. PSB/PSE Board Control Signals
In / Signal
Out*1)
Level
In TTL
In TTL
Out TTL
Out TTL
Logic
Block 1*2)
High 37 VDC
Low 0 VDC
High 0 VDC
Low 37 VDC
High
Indefiniteness
Low
High 37 VDC
Low < 35 VDC
Function
Block 2*3)
37 VDC, 5 VDC
37 VDC, 5 VDC
0 VDC, 0 VDC
37 VDC, 5 VDC
> 30 VDC, 5VDC
< 30 VDC, 5VDC
37 VDC, 5 VDC
< 35 VDC, 5 VDC
Rev. B