4. Analysis
During fixing my 7th screen, I made some analysis for diagnosis purpose. It should be quite helpful so I'm sharing them here.
PSone LCD screen block diagram
I created these when trying to understand the circuit. Major traces were mapped out and might be helpful for repairs.
I'm sorry that I can't append the original PSD file since it's over 100MB.
These two files are lined up so you can overlay them over each other and toggle the layer for continuity.
- IC1: MN5814 TFT AV Panel Controller IC, TQFP048
- IC3: WiseView LTS5QTB Controller, QFP-48
- IC4: ICS673M-01 PLL Building Block, SOIC-16
- IC5: V393 Dual Comparator (square wave oscillator), TSSOP-14
- IC6: STM M24C04-W 4Kb Serial I2C Bus EEPROM, TSSOP8
- IC7: LM4835 Stereo 2W Audio Power Amplifier with DC Volume Control & Selectable Gain, TSSOP
- IC8: OZ970G Intelligent CCFL Inverter Controller, SOP
- IC9: NJM2284 2-Input, 3-Channel Video Switch, SSOP-16
- IC10: LM1881M Sync Separator, SOIC-8
- IC11: 5410CR 4-Channel 30MHz Rail to Rail Output OP Amp, TSSOP-14
- IC12: AN2526NFH LCD TV Signal Processor IC, QFP064
- IC14: 74VHC4066 4-Channel Analog Switch, TSSOP
- PS1, PS2: 2.0A SMD
- LCD Screen: LTS500Q1-GF1
- 5" a-Si TFT active matrix
- 320H x 240V
- 15KHz Analog RGB
- 30-pin connector
- CCFL backlight
After power is applied, IC3 attempts to read settings from IC6 via the serial bus.
If something is wrong with IC6, IC3 will attempt to reinitialize IC6. If this fails, the system will become stuck in a loop. The screen will be stuck in an inverted state with no color or backlight, while sound will not be played.
-
SCL
- IC3: 27
- IC6: 6
- IC12: 47
-
SDA
- IC3: 28
- IC6: 5
- IC12: 48
IC3 sends serial commands to IC12 with contrast info.
IC3 sends OSD RGB signal to IC12 for muxing.
IC3 sends PWM info to the backlight system (IC8).
IC3 controls volume on IC7.
Apply 5V on DC_ON to enable console mode. Screen should turn on with backlight on.
Apply 5V to CM4 on the end near IC3 to force the backlight to turn on.