Samsung UE40F6400AX BN41-01958A BIOS EEPROM Firmware Dump Request

iuliancristiana68 wrote:

Samsung UE40F6400AX main BN41-01958A dump bin BIOS EEPROM firmware flash SPI @ElektrodaBot
AI: Which EEPROM chip (part number) do you need the dump for?
25Q40FVSIG
AI: What is the issue with your ...

Initial assessment of available information
- Set: Samsung UE40F6400AX (2013 F-series)
- Mainboard: BN41-01958A (PBA numbers start with BN94-…; useful but not mandatory for the SPI dump)
- SPI flash requested: Winbond 25Q40FVSIG (4 Mbit = 512 KiB)
- Symptom (Romanian): “nu funcționează, nu se aprinde LED-ul în standby” → completely dead, no red LED.
- From shared/online discussions: dumps for BN41‑01958A exist for multiple F6xxx models. However, “no standby LED” is far more often a standby power/sub‑micom (Weltrend WT61P8xx) issue than a “main BIOS” corruption. Several sample replies incorrectly suggest this is a “classic” EEPROM corruption case; that is not typical.

Where the 25Q40 sits on this chassis:
- It holds the sub‑micom (WT61P8xx) code and some board options.
- The main SmartTV OS (T‑MST12… for F6400) lives in eMMC, not in the 25Q40.
- The 24C256 I²C EEPROM (if present) holds option bytes/EDID/calibration.

Conclusion: reprogramming 25Q40 can cure “no standby LED” when the WT61P8 firmware is corrupt, but only after confirming the standby rails and the sub‑micom are powered and clocked.

Direct answer to your request (25Q40FVSIG dump)
- You need a 512 KiB BIN for BN41‑01958A, 25Q40 family (Winbond ID typically EF 40 13).
- Dumps from other F6xxx sets using the same BN41‑01958A often work for the sub‑micom, but panel- and region‑specific data live mainly in 24C256/eMMC. Still, always prefer an exact board/panel match when possible.
- I cannot attach binaries here. If another user uploads a 512 KiB BIN for BN41‑01958A (WT61P8 micom), it should be usable. Meanwhile, you can proceed with the diagnostics below to ensure flashing is meaningful.

Detailed problem analysis
1. Power supply isolation test
- Unplug AC, disconnect the mainboard from PSU, then apply AC.
- If the backlights come up by themselves, the PSU standby rail is present and the mainboard is suspect.
- If the backlights do not come up, fix the PSU/LEDs first; the mainboard/EEPROM is not the first suspect.

2. Verify standby rails on the mainboard
- At the PSU→MAIN connector, locate A5V / 5V_STBY. Expect ≈5.0 V with the set “off”.
- On BN41‑01958A, find the 3.3 V standby regulator (often an AMS1117‑3.3/LD1117‑3.3 or similar LDO) that feeds:
• WT61P8xx sub‑micom
• 25Q40FVSIG (pin 8 = VCC)
- Measure:
• 25Q40 pin 8 (VCC): 3.2–3.4 V
• 25Q40 pin 7 (HOLD#): pulled high (≈3.3 V)
• 25Q40 pin 3 (WP#): pulled high (≈3.3 V)
• 25Q40 pin 1 (CS#): high at idle, toggles low briefly on boot
• 25Q40 pin 6/5 (CLK/DI): activity on power‑up if the micom is alive
- If VCC = 0 V: trace back to the 3.3 V LDO or an input fuse near the main connector. Do not flash yet.

3. Sub‑micom health
- The WT61P8xx should have 3.3 V on its VCC and a running crystal (commonly 12 MHz). With a scope:
• If CS#/CLK never toggle and the crystal is silent, the micom is not running (no power, reset line held, bad oscillator, or the IC itself is bad).
• If there’s SPI activity but no LED, the micom executes code; firmware/data corruption becomes plausible.

4. Board shorts
- With power off, measure resistance from 3.3 V_STBY to GND on the mainboard. Very low resistance (<10–20 Ω) usually indicates a shorted MLCC on the 3.3 V line or a failed IC pulling the rail down.

5. When flashing the 25Q40 makes sense
- A5V and 3.3 V_STBY are good.
- The WT61P8xx oscillates or at least releases reset.
- SPI shows brief transactions at power‑up (best), or there is a history of corrupt dumps in similar failures.
- In these conditions, reprogramming the 25Q40 is a valid next step.

Current information and trends
- On F‑series boards, “no standby LED” is frequently cured by:
- Restoring 3.3 V_STBY (failed LDO/fuse/short).
- Reprogramming or replacing the WT61P8xx + its 25Q40 content.
- Complete eMMC rework is typically required for boot loops/logo hangs, not for fully dead sets.

Supporting explanations and details
- Device identity: 25Q40FVSIG is a Winbond part; typical JEDEC ID readout is EF 40 13. If your programmer shows 0xEF4017, that’s 25Q64, not 25Q40; do not force‑write with the wrong device selected.
- Size check: Correct file size is 524,288 bytes. Anything else is wrong/truncated.
- Protect pins: Ensure WP# and HOLD# are high during in‑circuit programming; otherwise writes/reads will fail.

Practical guidelines (flashing and safety)
- Tools: CH341A/TL866II/RT809H; SOIC‑8 clip or hot‑air for removal.
- CH341A caution: Many “black” CH341A programmers output 5 V on VCC by default—never feed 5 V to the 25Q40. Use the 3.3 V output or a proper adapter.
- Best practice:
1) Read the original at least twice; save as original_backup.bin and compare (hash/byte‑compare).
2) If the read is all 0xFF or 0x00 in large regions, the content is likely erased/corrupt.
3) Erase → Program → Verify 100% match.
4) After programming, re‑measure 3.3 V_STBY; then power the set. A red LED should appear within ~1–2 s if the micom boots.
- If still dead after a good flash and verified rails:
- Suspect the WT61P8xx IC itself (quite common). Replacement sometimes requires a pre‑programmed part or swapping from a donor board.
- As a last resort, replace the entire mainboard (match BN94‑xxxx PBA).

Corrections to misconceptions seen in sample replies
- “No standby LED = classic BIOS/EEPROM corruption” — Not typical. First suspects are A5V/3.3 V_STBY delivery and the WT61P8xx sub‑micom/oscillator.
- “25Q40FVSIG (GigaDevice)” — The part number you gave is Winbond; expect JEDEC EF 40 13, not a GigaDevice ID.
- Random regulator/SOC names (e.g., Richwave RT8193, Sigma/RDC) are not characteristic identifiers for this Samsung F‑series board and are not useful for this fault.

Ethical and legal aspects
- Dumps may include board‑specific identifiers (MAC, options). Use them strictly for repair of your unit. Always keep your original backup.

Suggestions for further research
- Service manual for UE40F6400/BN41‑01958A (for connector pinouts and standby rail maps).
- Look for a sub‑micom/25Q40 dump specifically labeled BN41‑01958A and, ideally, for your BN94‑… PBA. If a donor dump is used, you can later correct model options in service mode.

Brief summary
- Before flashing: verify A5V from PSU and 3.3 V_STBY at the 25Q40 and WT61P8xx. If 3.3 V is missing or there is no micom clock, flashing will not help.
- If standby rails and micom clock are OK, program a known‑good 512 KiB 25Q40 dump for BN41‑01958A; this often restores the standby LED.
- If still dead after a verified flash, suspect the WT61P8xx or a hardware short; next step is IC replacement or mainboard swap.

Questions for you (to move forward efficiently)
1) With the mainboard connected, what are your measurements for:
- A5V/5V_STBY at the PSU→MAIN connector?
- 3.3 V at 25Q40 pin 8?
2) Do you see any SPI activity on CS#/CLK at power‑up?
3) Can you read the current 25Q40 contents? What JEDEC ID and file size do you get?
4) What is the BN94‑xxxx number printed on your mainboard sticker, and what is the LCD panel code (on the panel label)?

Post these results, and if someone uploads a matching BIN for BN41‑01958A/25Q40 here, I’ll help you verify it before you flash.