User Guide: How to Use STB Loaders | Wiring, Steps & Troubleshooting

What you need

An Android 8.0 or newer phone that supports USB host (OTG)
An OTG cable or adapter for your phone's USB port
A USB-to-serial adapter: FTDI, CH340/CH341, CP210x, PL2303 or CDC/ACM
The right level for the receiver: RS232 for a DB9 port, TTL for a service header
The correct firmware file for your exact receiver model and board
A charged phone and stable receiver power

Connect the hardware

The chain is: Phone → OTG → USB-to-serial adapter → receiver service port. The Home screen shows this UART link and turns ready when the adapter is found.

Receiver port	Adapter	Wiring
DB9 RS232 port	USB-to-RS232	Standard serial cable to the receiver's RS232 port
TTL service header	USB-to-TTL (3.3 V)	Adapter TX → receiver RX, adapter RX → receiver TX, GND → GND. Do not connect VCC.

Never connect a TTL adapter or a TTL header directly to an RS232 voltage port. Wrong levels can damage the receiver or the adapter.

Step by step

Test the adapter. Plug in the adapter, open STB Loaders and tap Test adapter on Home. The loader pages show a green "adapter connected" banner when it is ready.
Open the loader. Use the bottom bar to open GX, ALI, Sunplus or Montage.
Receiver: select the exact receiver profile. Verified profiles are proven on real hardware.
Firmware file: tap Select and choose the firmware file. The app shows the file name and size and checks the size rule.
Programming: keep the receiver powered off, tap Program firmware and confirm.
Power on when asked. The app shows a prompt when it is time to turn the receiver on. It closes by itself when the receiver connects.
Wait for the result. Watch the Handshake, Initialize, Transfer and Program stages. Do not unplug anything until the result screen appears, then restart the receiver and check that it boots.

Chipset notes

GX

Firmware must be exactly 2, 4, 8 or 16 MiB. GX6605S Generic and GX6605H1 are Verified.

ALI

Firmware must be exactly 4 MiB. ALI 3510 is Verified. Supported profiles offer a UART parity choice (None / Even).

Sunplus

Choose the chip family and the Memory type (DDR2 or DDR3). Firmware from 8 KiB to 32 MiB.

Montage

Choose the flash chip size. Use 8 MiB only when the receiver has a physical 8 MiB flash chip. The chip is fully erased, then written.

Troubleshooting

No adapter found

Use a data-capable OTG cable, re-plug the adapter and allow USB access when Android asks. Check that the adapter chip is FTDI, CH340/CH341, CP210x, PL2303 or CDC/ACM, and that the phone supports USB host (OTG).

Adapter test fails

Unplug and re-plug the adapter, close other apps that may use it, then tap Test adapter again. Try another OTG cable if the phone charges the adapter but cannot open it.

The receiver does not answer (handshake)

Start with the receiver powered off and turn it on only when the app asks. Check TX/RX crossing and GND, the RS232/TTL level, and that the selected profile matches the board.

Transfer stops or is slow

Keep the phone charged and the cables still. Avoid USB hubs and long cables, keep Keep screen active on, and do not close the app during programming.

Firmware file is rejected

The file must match the size rule of the chipset: GX 2/4/8/16 MiB, ALI 4 MiB, Sunplus 8 KiB–32 MiB, Montage up to the selected 4 or 8 MiB flash size.

Session failed

Read the result screen: it names the stage that failed and the next step. Power-cycle the receiver, reconnect and program again. If it keeps failing, tap Submit Report so support can review it.

Useful settings

Language: tap the language button in the header. The language cannot change while an operation is running.
Keep screen active: stops the screen from sleeping during a session; manual lock still works.
Floating progress: a movable progress bubble over other apps (needs display permission).
Step guidance and Operation sounds: prompts and sounds for each important moment.
Support: Settings → Support to send a message with up to 3 screenshots.

Still stuck? Contact support.

How to use STB Loaders