Majority PETERHOUSE GRADUATE Internet Radio (Auna Silver Star) - Stuck at boot "Welcome" Screen

[praveenramavath]

Hello All,

I have an issue with my Majority PETERHOUSE GRADUATE Internet Radio, it keeps rebooting at the boot logo Welcome screen. I have an another forum active in other website but due to lack of response I am posting the same here. I am positing a link below that has pictures including all the troubleshooting I have tried, appreciate if someone can take a look and give me any suggestions.

https://www.hifivision.com/threads/m...-screen.98243/


Troubleshooting Summary: Majority Internet Radio - Flash Chip Power Issue

---

1. Problem Description

• Device: Majority Internet Radio
• Issue: Radio stuck during boot (hangs at "bar 6" after logo, then reboots).
• Suspected Cause: Flash memory (Winbond W25Q32JVSIQ) possibly not powered correctly.

---

2. Initial Investigation

• Measured voltages around an initially suspected AMS1117-3.3 (SOT-223 package):
  • Pin 1 (GND): 0V
  • Pin 2 (VOUT): 3.3V
  • Pin 3 (VIN): 3.33V
  • Tab (Metal Plate): 5.03V (unexpected)
• Winbond Flash (W25Q32JVSIQ) readings:
  • Pin 8 (VCC): 3.36V–3.38V
  • Pin 4 (GND): 0V
• Observed that when using a CH341A programmer (external 3.3V), the radio could boot fully.

---

3. Important Discovery

• After careful analysis, realized that the component thought to be an AMS1117-3.3 is actually a TPS61221 Boost Converter.
  • TPS61221 behavior: Boosts ~3.3V input to fixed 5V output (matches the observed 5.04V).
  • Conclusion: This component is working as intended.

---

4. Searching for Flash Power Source

• Identified two important components on the board:
  • 1x SOT-223 package (Large 3-pin IC)
  • 1x SOT-23-5 package (Small 5-pin IC)

4.1 SOT-223 Analysis

• Probed center pin of SOT-223 and Winbond VCC (Pin 8).
• Multimeter in continuity mode showed:
  • Resistance ramps up to ~1999Ω and back to 1Ω.
  • No beep (means not a strong direct connection).

4.2 SOT-23-5 Analysis

• Probed SOT-23-5 pins:
  • Pin 2 (Top-right) and Pin 4 (Bottom-right): Both show 3.3–3.5V.
  • Continuity testing between these pins and Winbond VCC (Pin 8) gave a strong beep.
  • Conclusion: SOT-23-5 output is directly tied to Winbond Flash VCC.

---

5. Action Taken

• Plan: "Tap" the 3.3V output from SOT-23-5 and feed it back to Winbond VCC (Pin 8).
• Decision:
  • NOT to lift the output pin from PCB.
  • Reason: Other components may also depend on this 3.3V rail. Lifting could break other circuits.
• Soldered a jumper wire from SOT-23-5 output (Pin 2) to Winbond Pin 8 directly.
• Confirmed good ground (Winbond Pin 4 already at 0V).

---

6. Results

• Powered on after modification.
• Result: No improvement.
  • Still stuck during boot (bar 6 freeze and reboot).

---

7. Equipment Limitations

• Only using a basic (partially faulty) multimeter.
• No oscilloscope available to check for noise, ripple, or transient issues.
• No bench power supply available for clean 3.3V injection.

---

8. Current Hypotheses

• Possibility 1: The 3.3V rail is noisy or unstable under load (not verifiable without oscilloscope).
• Possibility 2: The main SoC, Wi-Fi module, or flash controller circuit has failed.
• Possibility 3: Capacitor degradation (C76, C78, C79, C107, C108) causing unstable power delivery.

---

9. Next Steps (Need Advice)

• Would injecting external clean 3.3V directly to Winbond VCC and GND be safe to test?
• Should I attempt replacing suspected small capacitors?
• Is there another method to check if SoC is able to correctly communicate with Flash?

---

10. Notes

• Photos of the mainboard, SOT-223, SOT-23-5, and multimeter readings are available.
• Open to taking new voltage or resistance measurements if needed.

---

📢 Requesting Expert Advice

• Any suggestions on further isolating the fault?
• Safe troubleshooting steps considering limited equipment?

---

🔗 Quick Background

• CH341A flashing worked earlier (3.3V externally), radio booted fine with it.
• Current onboard 3.3V looks sufficient voltage-wise but unsure about quality.

[CapLeaker]

You said yourself “Current onboard 3.3V looks sufficient voltage-wise but unsure about quality.“
For shits and giggles add a small electrolytic smoothing capacitor and see what that does?!
other than that I think you may need to borrow an oscilloscope.
I just find it odd the radio works perfectly if you plug in the programmer to the SPI and USB, so it is powered up.
I wonder does your programmer provide 3.3V by just being plugged into the USB port?

[praveenramavath]

You said yourself “Current onboard 3.3V looks sufficient voltage-wise but unsure about quality.“
For shits and giggles add a small electrolytic smoothing capacitor and see what that does?!
other than that I think you may need to borrow an oscilloscope.
I just find it odd the radio works perfectly if you plug in the programmer to the SPI and USB, so it is powered up.
I wonder does your programmer provide 3.3V by just being plugged into the USB port?

Thanks, transient noise/unstability issue under load is suggested byGrok/Chatgpt, but I am not sure if that is the right reason. Yes, with CH341A programmer (3.3V) connected to Winbond Chip that has the firmware/boot code, radio turns ON and functions normally (Infact the winbond chip has pretty stable voltage reading of 3.3V without any external power sources or the programmer connected but still I am not sure what makes it boot only when CH341 is connected), I tried direct wiring between the SOT and winbond as well, but see no difference.. have also tried firnware/binary update on the winbond chip and resoldered it back without any success.

Here are 2 different brands of possibly the same hardware and identical firmware having the same issue, so it has to do with some common component/hardware in these models

[CapLeaker]

Just plug that programmer into a USB port and see if there is VCC is provided to the pin just by plugging it in? I am not sure it does and I don't have that programmer that you are using to check that.

The TPS61221 boost converter is a simple circuit on the output side is only one 10uF cap and a FB, that's it. On the input is an inductor, a 10uF cap and the enable pin, So either that 10uF cap is forked, there is something wrong with the 0.7Vrail, or the problem lies somewhere else and not at that regulator at all. Problem is you need something fast like an oscilloscope to see anything at ll. A DMM doesn't cut it, it's too slow.
Read the data sheet from the Winbond IC. There is a section what every pin does and how it works. Measure the resistance on the pull up resistors around the SPI.

Not sure how your internet radio is constructed, but I did repair at one point some IPTV boxes. One time everything looked o.k. but wouldn't boot at all. That was due to a bad series resistor (changed value on me somehow during repairs, got no idea how) on D0. Like this:
https://www.wpgdadatong.com/blog/detail/45832
Next problem: Is it using one data like D0 or is it using two lines D0 and WP (as D1). The 25Qxxxx datasheet tells you a lot what needs to be happening, but without a oscilloscope... man... not fun.

[stj]

you said

Measured voltages around an initially suspected AMS1117-3.3 (SOT-223 package):
Pin 1 (GND): 0V
Pin 2 (VOUT): 3.3V
Pin 3 (VIN): 3.33V
Tab (Metal Plate): 5.03V (unexpected)

pin2 is conected internally to the tab, so that makes no sense

[praveenramavath]

you said

pin2 is conected internally to the tab, so that makes no sense

What I thought as LDO is actually a booster converter TPS61221. The below one.


Below is the SOT that has direct continuity with W25Q32JVSIQ (Pin 8)


Below (Mainboard with main SOC, SOT to the right and W25Q32JVSIQ) is what I tried to isolate the issue with the SOT but no luck.