PlayStation 4
Board-Level Repair Guide
Complete board-level repair guide for the PlayStation 4 (CUH-1xxx, CUH-2xxx, Pro). Covers the most common failures: Blue Light of Death (BLOD), HDMI encoder (MN864729) faults, PSU no-power, APU VCORE issues and liquid damage. Use the interactive diagnostic tool below to pinpoint your fault in minutes.
Jump to your symptom
Board Specifications
| Parameter | CUH-1xxx (Fat) | CUH-2xxx (Slim) | CUH-7xxx (Pro) |
|---|---|---|---|
| Board ID | SAA-001 / SAB-001 / SAC-001 | SAD-001 / SAD-002 | NVA-001 / NVB-001 |
| APU | AMD Jaguar 8-core @ 1.6GHz | AMD Jaguar 8-core @ 1.6GHz | AMD Jaguar 8-core @ 2.1GHz |
| GPU | AMD GCN 1.84 TFLOPS | AMD GCN 1.84 TFLOPS | AMD GCN 4.2 TFLOPS |
| RAM | 8GB GDDR5 (4x Samsung K4G41325FC) | 8GB GDDR5 (8x Hynix H5GC4H24AJR) | 8GB GDDR5 + 1GB DDR3 |
| Southbridge | Marvell 88EC1000-BNN2 | Marvell 88EC1000-BNN2 | Marvell 88EC1000-BNN2 |
| HDMI Encoder | Panasonic MN864729 | Panasonic MN864729 | Panasonic MN86471A |
| Power IC | NCP81022 / RENESAS R4F2113 | Integrated in APU package | Multiple RENESAS VRM |
| PSU Output | +12V @ 17A / +5Vsb @ 1A | +12V @ 10.5A / +5Vsb @ 1A | +12V @ 25A / +5Vsb @ 1A |
Model Identification: CUH-1xxx series have external power supply brick connection and larger form factor. CUH-2xxx (Slim) has internal PSU with smaller footprint. CUH-7xxx (Pro) has enhanced cooling and additional processing power.
Voltage Rails
| Rail | Value | State | Regulator / Source | Test Point | Notes |
|---|---|---|---|---|---|
| +12V_MAIN | 12.0V | G3H | PSU Output | PSU connector pin 1-2 | Main power input from PSU |
| +5V_SB | 5.0V | G3H | PSU Standby | PSU connector pin 3 | Always-on standby power |
| +3.3V_SB | 3.3V | G3H | LDO from +5V_SB | Near southbridge | Standby logic power |
| +1.8V_SB | 1.8V | G3H | LDO from +3.3V_SB | Near WiFi module | Standby I/O power |
| +1.1V_APU_VCORE | 0.85-1.1V | S0 | NCP81022 VRM | APU inductor output | Dynamic voltage, load dependent |
| +1.35V_GDDR5 | 1.35V | S0 | Buck converter | RAM inductor output | GDDR5 memory power |
| +1.8V_APU | 1.8V | S0 | LDO near APU | APU bypass caps | APU I/O and PLL power |
| +3.3V_MAIN | 3.3V | S0 | Buck converter | Near HDMI/USB | Peripheral power |
| +5V_MAIN | 5.0V | S0 | Buck from +12V | USB port VBUS | USB and optical drive |
| +1.05V_HDMI | 1.05V | S0 | LDO near HDMI IC | Panasonic HDMI IC | HDMI transmitter core |
| +3.3V_HDMI | 3.3V | S0 | From +3.3V_MAIN | HDMI IC supply pins | HDMI I/O power |
| +2.5V_DISC | 2.5V | S0 | LDO | BD drive connector | Blu-ray drive logic |
APU Voltage Warning: The +1.1V_APU_VCORE is dynamically regulated and varies with load. Measure under consistent conditions. Normal idle voltage is approximately 0.85V, rising to 1.1V under heavy load.
Power Tree
AC MAINS → PSU
├─ +12V_MAIN (17A max) ─────────────────────────────────────
│ ├─ NCP81022 VRM → +1.1V_APU_VCORE (APU Core)
│ ├─ Buck Converter → +1.35V_GDDR5 (Memory)
│ ├─ Buck Converter → +5V_MAIN (USB/Optical)
│ ├─ LDO → +1.8V_APU (APU I/O)
│ └─ Buck Converter → +3.3V_MAIN (Peripherals)
│ ├─ HDMI Encoder Power
│ ├─ USB Controller
│ └─ WiFi/BT Module
├─ +5V_SB (Standby - Always On) ────────────────────────────
│ ├─ LDO → +3.3V_SB (Southbridge Standby)
│ ├─ LDO → +1.8V_SB (Logic Standby)
│ └─ Power Button Circuit → ACIN_CTRL
└─ GND (Common Return) ─────────────────────────────────────
Power Sequencing: The southbridge IC monitors +5V_SB and controls the main power-on sequence via the ACIN_CTRL signal to the PSU. The PSU will not output +12V_MAIN until ACIN_CTRL is asserted low by the southbridge.
Key Components
| Reference | Designation | Function | Rails | Location | Common Failure |
|---|---|---|---|---|---|
| U1 | AMD APU (Jaguar) | CPU + GPU integrated processor | +1.1V, +1.35V, +1.8V | Center of board under heatsink | YLOD (thermal), solder ball fracture |
| U2-U5 | Samsung K4G41325FC | GDDR5 RAM (2GB each) | +1.35V | Around APU (4 chips) | Memory corruption, blue screen CE-34878 |
| U10 | Marvell 88EC1000 | Southbridge / System Controller | +3.3V_SB, +1.8V_SB | Near front of board | No power on, stuck in standby |
| U15 | Panasonic MN864729 | HDMI Transmitter IC | +1.05V, +3.3V | Near HDMI port | No video, flickering output |
| U20 | NCP81022 | APU VRM Controller | +12V → +1.1V | Near APU, bottom side | No power, APU not starting |
| F1 | Fuse 15A | Main +12V protection fuse | +12V_MAIN | Near PSU connector | Open after short circuit |
| F2 | Fuse 3A | +5V_SB protection fuse | +5V_SB | Near PSU connector | Open, no standby power |
| Q1-Q4 | APU VRM MOSFETs | High/Low side switches | +12V → +1.1V | Near APU inductors | Shorted, PSU clicking |
| L1 | APU Core Inductor | VRM output filter | +1.1V | Large inductor near APU | Measure point for VCORE |
| U30 | Macronix MX25L25635F | 25Q SPI Flash (32MB) | +3.3V_SB | Near southbridge | Corrupt firmware, boot loops |
| J1 | HDMI Port | Video/Audio output connector | +5V HDMI | Rear I/O | Bent pins, torn pads |
| J2 | BD Drive Connector | SATA + Power to optical drive | +5V, +2.5V | Front of board | Disc read errors |
Boot Sequence
| # | Signal / Event | Expected Value | Condition | If Absent |
|---|---|---|---|---|
| 1 | PSU Connected | +5V_SB present | AC power connected | Check PSU, F2 fuse, AC cord |
| 2 | +3.3V_SB generated | 3.3V | +5V_SB present | Check standby LDO, southbridge |
| 3 | Southbridge initializes | SPI Flash accessed | Standby rails present | Check southbridge, SPI flash |
| 4 | Power button pressed | ACIN_CTRL pulled low | Button functional | Check button, ribbon cable |
| 5 | PSU enables +12V_MAIN | 12.0V | ACIN_CTRL asserted | Check ACIN line, PSU |
| 6 | VRM starts | +1.1V_APU | +12V present, enable signal | Check NCP81022, MOSFETs |
| 7 | GDDR5 rail enabled | +1.35V | Power sequence signal | Check RAM VRM, APU |
| 8 | APU exits reset | CPU_RST# deasserted | All rails stable | Check APU, memory, thermal |
| 9 | Firmware loads | Fan spins, LED pulse | APU running | Check SPI flash, APU |
| 10 | HDMI initialized | Video signal output | HDMI IC powered | Check Panasonic IC, HDMI port |
| 11 | System boot complete | Blue LED solid | OS loaded from HDD | Check HDD, file system |
LED Indicators: Blue = System on and healthy. White = System on (newer firmware). Orange = Rest mode. Blinking blue = Boot failure. Blinking white = Shutdown in progress. No LED = No standby power.
Interactive Diagnostic Tool
Record your measurements below, then click Analyze to receive targeted repair guidance based on the PS4 power tree and boot sequence.
Measurements taken — click OK / NOK / NR (Not Recorded) for each rail
Enter at least a few rails then click Analyze.
No Power / No Turn On
Symptom Categories
Completely Dead (No LED, No Fan):
- Verify AC power at outlet and power cable integrity
- Check PSU output: +5V_SB should be present with AC connected
- Test PSU with multimeter or known good unit
- Check fuses F1 (15A) and F2 (3A) for continuity
- Inspect PSU connector solder joints on motherboard
- Look for liquid damage indicators around power input area
Blue Light Pulses Then Dies:
- APU is attempting to start but failing
- Check +1.1V_APU_VCORE - may be missing or unstable
- Check +1.35V_GDDR5 memory rail
- Inspect thermal paste/pads - APU may be overheating instantly
- Check APU for physical damage or previous rework
- Verify clamp force on heatsink mounting
PSU Clicks Repeatedly:
- PSU is detecting overcurrent and shutting down
- Short circuit present on +12V_MAIN rail
- Check MOSFETs Q1-Q4 for shorts (most common cause)
- Measure resistance to GND on APU inductor L1
- Normal: >1kΩ. Shorted: <100Ω
- Do NOT keep trying to power on - will damage PSU
Beep Codes:
- 1 beep: Normal power on
- 2 beeps: Disc ejected
- 3 beeps: Power off / Safe mode entered
- Continuous beeps: Overheating warning
UART Diagnostic
The PS4 exposes a UART debug port that outputs boot-stage messages and error codes. This is the fastest way to pinpoint a BLOD failure — it tells you exactly which stage the boot sequence fails at before the console shuts down.
UART Test Pad Location
| Pad | Signal | Board Revision | Location |
|---|---|---|---|
| JP3502 | TX (PS4 transmit → your adapter RX) | CUH-1000 / 1100 / 1200 | Underside, near PSU connector, small oval pad |
| JP3503 | RX (your adapter TX → PS4) | CUH-1000 / 1100 / 1200 | Adjacent to JP3502 |
| GND | Ground reference | All | Any nearby ground pad or shield screw hole |
⚠ Voltage level: The UART is 3.3 V logic. Never connect a 5 V adapter directly — you will damage the southbridge. Use a CP2102, CH340 or FT232 adapter set to 3.3 V.
Connection Setup
- Set adapter to 3.3 V logic (jumper or dedicated 3.3 V model)
- Solder fine-gauge wire (30 AWG) to JP3502 (TX) and JP3503 (RX)
- Connect: PS4 TX → adapter RX, PS4 RX → adapter TX, GND → GND
- Open terminal: 115200 baud, 8N1, no flow control (PuTTY, minicom, screen)
- Power on PS4 — output appears immediately
Full UART Boot Stage Map
Stages are listed in boot order. The last line printed before shutdown identifies the fault layer. Hardware faults occur in the first half; software/storage faults in the second half.
| UART Output | Stage | Diagnosis |
|---|---|---|
| No output at all | Southbridge not initialising | Hardware: No +5V_SB or southbridge dead. Check F2 fuse, PSU standby output |
EMC init done | Southbridge init OK | Hardware: +5V_SB and +3.3V_SB present. Failure after this → check +12V_MAIN / VRM |
DDR init... then stops | RAM init failure | Hardware: Check +1.35V_GDDR5 rail. Suspect RAM chips or APU memory controller |
DDR init done → stops at APU init | APU failed to start | Hardware: Check +1.1V_APU_VCORE. Suspect NCP81022 VRM or APU solder joints |
SFlash read error | Firmware read failure | Hardware: SPI flash (Macronix MX25L25635F) corrupt or unresponsive. Read with programmer |
acp* codec lines loading | APU firmware executing | Hardware OK to this point. APU running, audio codecs loading. Fault is downstream |
Belize SATA PHY init | SATA controller init | Hardware: Southbridge SATA PHY initialising. Repeating 3x is normal (PHY training loop). If stuck here: check SATA connector on board |
GEOM_CRYPT: eap key setup → panic: eap key not available | Encryption key missing | Software/Storage: HDD swapped without recovery init, or system partition corrupted. Boot recovery (hold power 7s, 2nd beep) → option 7 Reinstall. If recovery also panics: APU secure key storage gone → board-level (APU replacement) |
UVFAT_Initialize: exit then hangs | FAT filesystem mount failure | Software: USB/update partition unreadable. Check HDD health. Try recovery option 4 (rebuild database) or option 7 |
[REGMGR] 000006 / 010007 / 000108 | Kernel panic register dump | Crash log codes, not directly actionable. Look at the panic line above them for the actual fault |
HDMI init failed | HDMI encoder error | Hardware: MN864729 not responding. Check +1.05V and +3.3V at IC, inspect I²C lines |
Common UART Error Codes
| Code | Meaning | Repair Direction |
|---|---|---|
0x80010017 | Cannot find firmware partition | HDD/SSD or SPI flash corruption |
0x80010006 | APU thermal shutdown | Thermal paste, heatsink clamp, VRM instability under load |
0xC0020001 | Memory ECC error | Failed GDDR5 chip — check +1.35V stability, reflow RAM |
0x80020148 | HDMI output failure | MN864729 — check voltages, I²C, replace if unresponsive |
No Video / HDMI Issues
The PS4 uses a dedicated Panasonic MN864729 HDMI encoder IC. Video issues are extremely common due to the exposed HDMI port location.
Diagnostic Flowchart
| Symptom | Likely Cause | Diagnostic Steps |
|---|---|---|
| No video, system boots (audio works via optical) | HDMI IC or port failure | Check HDMI port pins, measure +1.05V and +3.3V at HDMI IC |
| Flickering / sparkling video | Bad solder joints on HDMI port | Reflow HDMI connector, check for cold joints |
| No video, no audio, blue light on | APU video output failure | Check APU power rails, may need reball/replacement |
| Video cuts out when cable moved | HDMI port mechanical damage | Replace HDMI port connector |
| Works briefly then loses signal | Thermal issue or intermittent short | Check HDMI IC temperature, look for solder bridges |
HDMI Port Replacement Procedure
- Remove motherboard from chassis
- Apply flux to all HDMI port pins
- Pre-heat board to 150°C from bottom
- Use hot air at 380-400°C to remove old port
- Clean pads thoroughly - inspect for lifted traces
- Apply fresh solder to pads if needed
- Align new port carefully - pins are very fine pitch
- Reflow with hot air, add solder to anchor points
- Check for bridges under magnification
HDMI IC Replacement: The Panasonic MN864729 is a BGA chip requiring professional rework equipment. Incorrect removal will damage the PCB. This is a Level 4 repair requiring BGA rework station and stencils.
Liquid Damage
PS4 consoles commonly suffer liquid damage from spilled drinks, humid environments, or condensation from temperature changes (console moved from cold to warm room).
Immediate Response Protocol
- DO NOT power on - causes electrolytic corrosion
- Disconnect all power immediately
- Disassemble to motherboard level within 24 hours
- Remove all shields and heatsinks
- Document affected areas with photos
Cleaning Procedure
- Initial rinse: 99% isopropyl alcohol bath, agitate gently
- Ultrasonic clean: 5-10 minutes in heated IPA (40°C max)
- Targeted cleaning: Soft brush on corroded areas
- Under-chip cleaning: Flux + hot air to wick out contamination
- Dry thoroughly: Compressed air, then 4+ hours at room temp
- Inspect under microscope: Look for remaining corrosion
Common Liquid Damage Failure Points
| Area | Symptoms | Repair |
|---|---|---|
| Power button flex area | No power on, intermittent power | Replace flex cable, clean connector |
| Disc drive connector | Disc not recognized, eject issues | Clean pins, replace connector if corroded |
| USB ports | Controllers not charging/connecting | Replace USB daughter board |
| HDMI area | No video, intermittent display | Clean and reflow HDMI port and IC |
| WiFi/BT module | No wireless connectivity | Replace WiFi/BT module |
| APU area (severe) | No power, YLOD symptoms | Often unrepairable - APU damage |
Corrosion Under BGA Chips: If liquid penetrated under the APU or RAM chips, corrosion can cause intermittent failures months later. Proper ultrasonic cleaning is essential even if the console initially works after drying.
Short Circuit Diagnosis
Method A: DC Power Injection
Inject controlled current into a shorted rail to identify the faulty component through voltage drop measurement or thermal detection.
| Rail | Injection Voltage | Current Limit | Max Duration | Injection Point |
|---|---|---|---|---|
| +12V_MAIN | 1.0V | 2.0A | 30 sec | PSU connector pad |
| +5V_SB | 1.0V | 1.0A | 30 sec | PSU connector pin 3 |
| +3.3V_MAIN | 1.0V | 1.0A | 30 sec | 3.3V inductor output |
| +1.1V_APU | 0.5V | 3.0A | 15 sec | APU inductor L1 |
| +1.35V_GDDR5 | 0.5V | 2.0A | 15 sec | RAM inductor output |
Warning: Never inject voltage higher than the rail's normal operating voltage. Use current-limited bench PSU only. Monitor temperature continuously with thermal camera.
Method B: Thermal Imaging
- Set up thermal camera (FLIR or similar) focused on suspected area
- Inject low voltage as per table above
- Watch for hot spots developing - shorted component will heat first
- Typical short will reach 50-80°C within 5-10 seconds
- Stop immediately once located to prevent damage
Method C: Divide and Conquer
For shorts that cannot be thermally located:
- Identify all components connected to the shorted rail
- Remove components one at a time, starting with easiest/cheapest
- Test rail resistance after each removal
- When resistance returns to normal, last removed component is faulty
Normal Rail Resistance Values (Unpowered)
| Rail | Normal Resistance to GND | Shorted Indication |
|---|---|---|
| +12V_MAIN | >5kΩ | <100Ω |
| +5V_SB | >500Ω | <50Ω |
| +3.3V_MAIN | >200Ω | <20Ω |
| +1.1V_APU | >100Ω (varies) | <10Ω |
| +1.35V_GDDR5 | >50Ω | <5Ω |
Measurement Note: Use diode mode on multimeter for more sensitive short detection. Compare readings between known good board and suspect board when possible.
Measurement Points
| Signal / Rail | Test Point Location | Expected Value | Conditions |
|---|---|---|---|
| +12V_MAIN | PSU connector pins 1-2 (large pins) | 12.0V ±5% | System powered on |
| +5V_SB | PSU connector pin 3 (small pin) | 5.0V ±5% | AC connected (always on) |
| +1.1V_APU_VCORE | Large inductor L1 near APU (output side) | 0.85-1.1V | System running, varies with load |
| +1.35V_GDDR5 | Inductor near RAM chips (output side) | 1.35V ±3% | System running |
| +3.3V_SB | Capacitor cluster near southbridge | 3.3V ±5% | AC connected (always on) |
| +1.8V_SB | Near WiFi/BT module connector | 1.8V ±5% | AC connected (always on) |
| ACIN_CTRL | PSU connector (small signal pin) | High standby, Low when pressed | Measure during power button press |
| APU Presence | Fan header voltage | 12V PWM signal | Fan should spin on boot attempt |
| HDMI +5V | HDMI port pin 18 | 5.0V | System running, HDMI connected |
| USB VBUS | USB port pin 1 | 5.0V | System running |
| BD Drive Power | Disc drive connector | 5.0V + 2.5V | System running |
| Clock (32.768kHz) | Crystal near southbridge | 32.768kHz oscillation | Oscilloscope, standby power present |
Oscilloscope Measurements: For VRM troubleshooting, check switching frequency at MOSFET gates (typically 300-500kHz). Missing switching indicates VRM controller issue. Erratic switching suggests feedback loop problems.
Recommended Tools
Digital Multimeter
Fluke 87V or equivalent with accurate millivolt and diode mode
Hot Air Station
Quick 861DW or Hakko FR-810 for component removal/replacement
Soldering Station
Hakko FX-951 or JBC CD-2BE with fine tips for precision work
DC Bench Power Supply
30V/5A minimum with current limiting for injection testing
Thermal Camera
FLIR ONE Pro or better for locating shorted components
Stereo Microscope
AmScope or similar, 7-45x zoom for PCB inspection
Ultrasonic Cleaner
Heated unit with IPA-safe tank for liquid damage cleaning
Oscilloscope
Rigol DS1054Z or similar 4-channel for signal analysis
BGA Rework Station
Required for APU/RAM work - IR or hot air with bottom preheat
Flux
Amtech NC-559 or Kingbo RMA-218 for BGA work
Torx Drivers
T8 and T9 Security Torx for PS4 disassembly
Thermal Paste
Thermal Grizzly Kryonaut or Noctua NT-H1 for reassembly
Frequently Asked Questions
What is the most common failure on PS4 consoles?
The most common failure is HDMI port damage from improper cable handling or insertion. The port's solder joints crack or pins bend, causing no video output. This is followed by APU-related failures (BLOD - Blue Light of Death) caused by thermal stress or solder joint degradation under the APU chip.
What are the symptoms of a failing PS4 APU?
A failing APU typically presents as the Blue Light of Death (BLOD) where the console pulses blue light briefly then shuts down, or the White Light of Death (WLOD) where it shows white light but no video output. These symptoms indicate the APU is either not starting properly or failing to initialize video output. In severe cases, the console may not power on at all.
How difficult is PS4 HDMI port replacement?
HDMI port replacement is considered a Level 3 repair requiring hot air rework skills and experience with fine-pitch connectors. The main challenges are removing the old port without lifting pads, cleaning the area properly, and aligning the new port precisely. With proper equipment and practice, success rates exceed 90%. Budget 30-45 minutes for an experienced technician.
What tools are essential for PS4 board repair?
Essential tools include a quality hot air station (380-420°C capability), fine-tip soldering iron, stereo microscope (20x minimum), digital multimeter with millivolt accuracy, and flux. For advanced repairs, add a thermal camera for short detection, bench power supply for injection testing, and oscilloscope for signal analysis. Total investment for basic setup is approximately $500-800.
Can a PS4 be recovered after liquid damage?
Recovery depends on the type and extent of liquid exposure and how quickly the console was powered off. Sugar-containing liquids (soda, juice) cause rapid corrosion and have lower success rates. If cleaned within 24-48 hours before corrosion sets in, success rates can exceed 70%. Key is complete disassembly, ultrasonic cleaning with isopropyl alcohol, and thorough inspection for damaged components.
What is a typical repair cost for PS4 board-level issues?
HDMI port replacement typically costs $80-150 at independent repair shops. Power supply issues range from $60-120 depending on whether it's the PSU unit or motherboard components. APU-related repairs involving reball or replacement range from $150-300 but have variable success rates. These prices compare favorably to Sony's flat-rate repair of $150+ or replacement console purchase.
Why does my PS4 turn on briefly then shut off?
This symptom indicates the system attempts boot but fails a critical check. Common causes include: shorted VRM MOSFETs triggering overcurrent protection, missing APU core voltage, failed RAM chips, or corrupted firmware. Start diagnosis by checking standby voltages, then main rail voltages during the brief power-on window. Use current-limited bench supply to identify which rail is drawing excessive current.
📐 Schematic: View PS4 CUH-1200 schematic files →