Before you flash: Flashing firmware will erase all data on your device. Back up contacts, photos, and apps before proceeding. FlashGuideHub is not responsible for any damage caused by following this guide.
About the Hotwav Cosmos V4
The Hotwav Cosmos V4 was released in April 2016. It is an affordable Android smartphone equipped with a 6.0-inch qHD screen and powered by the Spreadtrum SC7731G processor.
Flashing the factory PAC firmware allows you to repair corrupted system files, recover from boot loops, and restore your device to original factory condition. Follow the step-by-step instructions below to flash your phone safely.
Which Flash Mode Should You Use?
SPD Upgrade Tool (PAC Flash Mode)
Official factory flashing procedure for Spreadtrum SC7731 devices using complete PAC archives.
What You Need Before Flashing
SPD Upgrade Tool runs on Windows 7, 8, 10, or 11. Install Spreadtrum USB drivers before starting.
Download and extract the official stock firmware archive to obtain the .pac file.
Use a high-quality microUSB data cable connected directly to a rear USB port on your PC.
Make sure the 2050 mAh battery has enough charge to prevent the phone from powering off during flashing.
Flashing stock PAC firmware wipes all user data and installed apps. Back up your files beforehand if possible.
How to Flash the Hotwav Cosmos V4 — Quick Overview
5-step quick reference for the Hotwav Cosmos V4. Need visuals or troubleshooting help? The full SPD Upgrade Tool guide covers everything in detail.
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Download and extract the firmware
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Install Spreadtrum (SPD) USB drivers
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Open SPD Upgrade Tool and load the PAC file
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Start download and connect the phone
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Wait for completion and reboot
Firmware Package for Spreadtrum SC7731
The Hotwav Cosmos V4 uses a Spreadtrum SC7731 processor, so its firmware is packaged as a single PAC (.pac) container rather than an MTK scatter text file. The PAC archive bundles all raw partition binaries (FDL1, FDL2, boot, recovery, system, and userdata) inside one package that the SPD Upgrade Tool unpacks and flashes automatically.
Hotwav_Cosmos_V4_*.pac
Load the extracted .pac firmware package directly into SPD Upgrade Tool using the Load Packet (single gear) button. The tool automatically maps all required partition images.
Hardware check: This package is built exclusively for the Spreadtrum SC7731 chipset version of the Hotwav Cosmos V4. Never try to flash this file onto MediaTek devices or use SP Flash Tool. Loading an SPD PAC file requires SPD Upgrade Tool or ResearchDownload Tool.
Hotwav Cosmos V4 Firmware Versions
Official stock PAC firmware for the Hotwav Cosmos V4. Verify your device model under the battery before proceeding.
| Version | Region | Android Version | Size | MD5 | Download |
|---|---|---|---|---|---|
20160405 |
Global / Dual SIM | Android 5.1 (Lollipop) | 720 MB | — | ⬇️ Download |
Need more technical details, repair checklists, or alternative archive links? View the complete archive on AndroidFirmwareFile.com →
Hotwav Cosmos V4 — Important Notes
The Hotwav Cosmos V4 uses a removable 2050 mAh lithium-ion battery. Before beginning the flash process, remove the battery for 5 seconds and put it back in to ensure the device is completely powered down. When connecting to your PC, keep the boot key (Volume Down) held until the SPD Upgrade Tool shows an active blue progress bar.
Common Errors on the Hotwav Cosmos V4
Waiting for device / Phone powers on normally instead of flashing
The phone did not enter Spreadtrum download mode. Turn off the phone, remove and reinsert the battery, hold the Volume Down button firmly, and plug in the USB cable. Also make sure the Spreadtrum USB driver is installed in Windows Device Manager.
Baudrate error / Download Failed in SPD Upgrade Tool
This happens if communication between the PC and phone is unstable. Try connecting the USB cable to a rear motherboard USB port, use a shorter microUSB cable, or lower the baudrate in the tool settings.
Phone hangs on Hotwav logo on first boot after flashing
The first boot after flashing can take up to 5 to 8 minutes as Android rebuilds its system cache. If it takes longer than 10 minutes, pull the battery, boot into Recovery mode (Volume Up + Power), and select "Wipe data / factory reset".
For common SPD Upgrade Tool errors and troubleshooting: Spreadtrum Flashing Error Directory →
Frequently Asked Questions — Hotwav Cosmos V4
The Hotwav Cosmos V4 runs on a Spreadtrum SC7731 processor. You should use the SPD Upgrade Tool (also known as UpgradeDownload) or ResearchDownload Tool. Do not use SP Flash Tool, because SP Flash Tool is only for MediaTek devices.
For Spreadtrum SC7731 phones, the most common boot key is Volume Down. Turn the phone off completely, hold Volume Down, and plug in the USB cable. If the tool does not detect it, try holding Volume Up instead.
Yes. Flashing a full factory PAC firmware completely wipes internal storage, replacing system, user data, and cache partitions. Back up your important files before flashing if your phone still boots.
Yes. If your phone is stuck in a boot loop or will not start due to corrupted system files, flashing the official PAC file will restore the factory operating system and fix the issue.
Ready to Flash?
Follow the full step-by-step SPD Upgrade Tool guide with interactive progress tracking, prerequisite checklist, and complete troubleshooting.