BIOS: Flashing CW_ADLN_NAS V1.1 N355 with CH341a (CW-NAS-AT-4L)

Following the instructions below and flashing the BIOS sent by @loodd worked and the system is stable, including an overnight memtest86+.

BIOS (Warning: Windows Defender quarantines this file as a Trojan): https://drive.x86pi.cn/BIOS/5.NAS-BIOS/Twin_Lake(N150-N250-N350-i3-N355)/CW-NAS-AT-4L

# CWWK N355 BIOS Recovery Guide with CH341a

This is a reference guide to help myself in future, if you choose to use it - **be careful**.

## Problem Summary

• Board: CWWK N355 CW-NAS-AT-4L (CW_ADLN_NAS V1.1) with 4x i226-V NICs
• Issue: Incorrect BIOS flash causing no POST (you could also just have corrupted BIOS or no POST issues)
• Solution: CH341A programmer recovery

## Required Equipment

• CH341A USB programmer with SOIC8 clip
• Linux PC (recommended for reliability)
• CW-NAS-AT-4L-N150-N305-N355.iso from https://drive.x86pi.cn/BIOS/5.NAS-BIOS/Twin_Lake(N150-N250-N350-i3-N355)/CW-NAS-AT-4L
• USB extension cable (between programmer and PC/Laptop - you may be reconnecting the programmer a lot)

## Recovery Procedure

### Step 1: Software Setup (Linux)

# Install flashrom
sudo apt install flashrom

# Verify installation
flashrom --version

• You will need to extract the binary `.bin` from the ISO.
• So mount or extract the ISO contents, and find the `.bin` file `20250903_161405/CW-TY-BIOS/bios/CWRADLNB01.bin`.
• Place this in the directory you launch `flashrom` from.

### Step 2: Hardware Preparation

1. **Power off CWWK board completely** - unplug all power cables
2. **Remove CMOS battery** - for safety when writing the chip
3. **Locate BIOS chip** - Winbond 25Q128JV near CMOS battery
4. **Note pin 1** - marked with dot or notch on chip

### Step 3: Connect Programmer

1. Attach SOIC8 clip to CH341A programmer **ensure correct pins**
2. Clip onto BIOS chip with **red wire to pin 1**
3. Ensure firm connection on all pins (I had to try this multiple times before I could `flashrom -p ch341a_spi -r backup.bin`)
4. Connect CH341A to PC USB port

### Step 4: Backup Current BIOS

# Read current BIOS (even if corrupted)
sudo flashrom -p ch341a_spi -r corrupted_backup.bin

# Verify chip detection shows:
# "Found Winbond flash chip W25Q128"

### Step 5: Flash Correct BIOS

# Write manufacturer BIOS with verbose output
sudo flashrom -p ch341a_spi -w CWRADLNB01.bin -V

# (optional) Verify the flash was successful, writing already verifies once.
sudo flashrom -p ch341a_spi -v CWRADLNB01.bin

### Step 6: Post-Recovery

1. Disconnect CH341A programmer
2. Remove SOIC8 clip from chip
3. Plug in CMOS battery, and reconnect board power
4. Power on - **first boot takes 2-3 minutes** (memory training)
5. Enter BIOS (DEL key)

### Optional Memory Optimization (after confirming boot)

If experiencing instability with 32GB SO-DIMM:

• Memory: 4000 MHz
• Gear Mode: Gear 2
• MRC ULT Safe Config: Enabled

## Troubleshooting

### Chip Not Detected

• Check clip alignment and connection
• Try slower USB 2.0 port
• Ensure board power is disconnected

### Verification Failed

• **DO NOT remove clip**
• Retry flash command
• Check BIOS file integrity

### No POST After Flash

• Clear CMOS (JBAT jumper)
• Verify correct BIOS version for your board variant

## Critical Warnings

⚠️ **Never power board with programmer attached**  

⚠️ **Ensure solid clip connection before operations**  

⚠️ **Use correct BIOS for your board variant**

## Expected Outcome

✓ All 4 Ethernet ports functional  

✓ System POST successful  

✓ Memory stability improved with latest BIOS

## Linux vs Windows

**Linux recommended**: Direct hardware access, better error reporting, proven reliability with flashrom

**Windows alternative**: AsProgrammer software if Linux unavailable

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Support request below

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Hello,

I flashed this version of the BIOS:

CW-NAS-ADLN-KV10_noBootSATA_20240624.iso

And since then there is no POST on the system. What is the correct version? Maybe this: CW-ADLN-NAS(N100-N305).2024.11.12_NoLogo.iso

Is there any way to recover without flashing the chip directly? I've found this flashing tool will it work for the WinBond 25Q128JVSQ 2411? And what is the process for flashing, can I simply flash the .bin of the CORRECT BIOS?

Any help is welcome, the system is now bricked...

P.S. I found a sticker under the RAM module this is an i3-n355 - not n305