Alcor Micro SC708AN/AU6987AN USB Flash Disk 7.76 Not Detecting NAND, Flash ID E7FFFFFFFFFF

User question

Description: [G:]USB Mass Storage Device(Generic USB Flash Disk)
Device Type: Mass Storage Device

Protocal Version: USB 2.00
Current Speed: High Speed
Max Current: 100mA

USB Device ID: VID = 058F PID = 1234

Device Vendor: Alcor Micro
Device Name: Mass Storage Device
Device Revision: 0001

Manufacturer: Generic
Product Model: USB Flash Disk
Product Revision: 7.76

Controller Vendor: Alcor Micro
Controller Part-Number: SC708AN/AU6987AN [CA09] - F/W AA12
Flash ID code: E7FFFFFFFFFF - 8CE/Dual Channel [QLC]

Artificial Intelligence Response

Direct answer to the question

• Your flash drive enumerates as an Alcor Micro SC708AN/AU6987AN (FW AA12) USB‑2.0 device drawing 100 mA.
• The Flash ID readback E7FFFFFFFFFF is effectively “no valid NAND ID” (all 0xFF after the first byte), which strongly indicates the controller cannot properly communicate with the NAND array.
• Practically, this points to failed NAND, a broken NAND bus (solder/joint/PCB damage), or a controller/NAND‑interface fault. If data matters, stop using it and seek professional recovery. If not, you can attempt re‑initialization with Alcor’s MP (mass‑production) tool, understanding it will erase data and may still fail.

Key points

• VID:PID 058F:1234 and the “Generic USB Flash Disk 7.76” string are typical of low‑end, sometimes counterfeit, devices.
• “8CE / Dual Channel [QLC]” suggests an 8‑chip‑enable, 2‑channel layout with low‑endurance QLC NAND, but because the ID is invalid, those descriptors may be database guesses and should be treated as uncertain.
• Expect low probability of reliable repair; replacement is usually the sensible path.

Detailed problem analysis

• USB layer: The device enumerates stably at USB 2.0 High‑Speed and 100 mA, so the USB PHY/stack is alive. Enumeration alone does not prove the NAND backend is healthy; the controller can still present as a mass‑storage target even when it cannot access flash.
• Controller: SC708AN/AU6987AN is an Alcor family often used in generic sticks. These controllers rely on reading an ONFI/JESD‑style ID sequence from each CE (chip enable) at power‑up to build the bad‑block table and geometry. If the ID readback is all 0xFF, the controller either:
  • sees the data bus floating (open circuits, cracked BGA/TSOP/QFN joints, lifted pads, broken traces),
  • cannot bring the NAND out of reset (bad R/B#, CE#, CLE/ALE timing or power rail fault),
  • or the die is electrically dead.
• Flash ID “E7FFFFFFFFFF”: A valid NAND ID is multiple bytes: manufacturer code + device code(s). All 0xFF after the first byte is a canonical symptom of “no response.” The single E7 byte is not sufficient to positively identify the vendor. Treat this as “NAND not detected.”
• 8CE/Dual channel [QLC] note: “CE” denotes chip‑enable lines; 8CE implies up to eight packages/dies selected by the controller. Dual channel means two independent data channels for higher throughput. QLC stores 4 bits/cell, trading endurance for capacity. Even when healthy, QLC USB sticks are more fragile under write stress and power‑loss.
• Likely user‑visible symptoms: zero/incorrect capacity, RAW filesystem, frequent disconnects, I/O errors, sudden read‑only, or “please insert a disk.”

Theoretical foundations

• NAND bring‑up sequence: power rails good -> reset -> read ID -> read parameter page -> build translation/bad‑block maps. Failure at “read ID” almost always blocks further initialization.
• All‑0xFF or all‑0x00 patterns on the ID/data bus indicate open/short conditions or dead silicon.

Practical applications

• Forensically, once a controller cannot identify NAND reliably, safe imaging through the standard USB block interface is unlikely. Professional recovery bypasses or removes the controller (chip‑off, direct NAND read) and reconstructs the translation layer.

Current information and trends

• Generic VID/PID pairs and “Generic USB Flash Disk” strings are commonly reported on low‑cost or counterfeit drives that misreport capacity.
• Increased use of QLC in budget media over the past years has reduced endurance margins; failure under typical consumer write patterns is more common than with TLC/MLC.
• Alcor MP tools exist for AU6987/SC708 families; they can re‑initialize NAND, set true capacity, and rewrite firmware, but they are destructive to data and success depends on NAND health.

Supporting explanations and details

• Why the USB layer can look fine while flash is dead: the controller’s MCU and USB PHY can enumerate independently; only when you attempt read/write does the backend failure surface.
• Why capacity may change after MP‑tool reinit: the tool may detect only a subset of dies/planes or will down‑bin capacity to avoid failing regions; a “32 GB” stick may reappear as, say, 8 GB of genuinely usable space.
• Thermal/mechanical issues: inexpensive sticks often have minimal mechanical support; flexing can fracture solder joints on TSOP/BGA NAND.

Ethical and legal aspects

• Using third‑party or leaked MP tools may violate licenses and can carry malware risk; obtain software from trusted, legitimate sources only.
• If the drive may contain sensitive data, consider secure handling and certified e‑waste disposal. Professional recovery labs should sign NDAs upon request.

Practical guidelines

If data recovery is required

• Stop all write attempts immediately; do not run MP tools (they erase/initialize).
• Stabilize and image:
  • If the drive still mounts intermittently, attempt a full, non‑caching image with a tool that handles bad sectors and resets (e.g., ddrescue on Linux). Expect limited success given the ID failure.
  • If imaging fails or the device repeatedly re‑enumerates, professional NAND‑level recovery (e.g., chip‑off) is the only realistic option.
• Choose a lab experienced with Alcor controllers/NAND reconstruction; request an assessment before authorizing full work.

If data is not required and you just want a usable stick (low success probability)

• Basic checks first:
  • Try on several USB 2.0 ports directly on the motherboard and on another PC/OS.
  • Observe event logs: Windows Event Viewer (disk/ntfs/Kernel‑PnP), or Linux dmesg (USB resets, device I/O errors).
• Attempt controller re‑initialization:
  • Use the Alcor Mass‑Production (MP) tool version for AU6987AN/SC708AN.
  • Configure detection to auto‑identify NAND; do not hard‑code IDs unless you are certain.
  • Run a full low‑level init including erase, bad‑block scan, and capacity calibration.
  • If it completes, validate the device with a full‑capacity write/verify test (H2testw on Windows or F3write/F3read on Linux). Only trust the device if it passes a complete cycle with zero errors.
• If MP‑tool fails to detect NAND, abort. The NAND or controller hardware is unsalvageable in‑situ.

Hardware inspection (advanced, ESD‑safe, only if you’re equipped)

• Open the casing; inspect under magnification for cracked TSOP/BGA solder joints on the NAND and controller, lifted CE/WE/RE/DQ lines, and corrosion.
• Check VCC, VCCQ rails, and reset pin on NAND with a scope or DMM during power‑up; absent rails or a stuck‑low R/B#/CE# suggest power/reset issues.
• Rework/reflow is risky and often not durable on low‑cost PCBs; attempt only if data is non‑critical.

Possible disclaimers or additional notes

• Because the Flash ID is invalid, any mention of NAND vendor/model or exact geometry is speculative.
• Even if you revive the stick, QLC endurance and prior failure strongly argue against using it for anything important.
• Some MP‑tool packages found online bundle adware/malware; exercise strict caution.

Suggestions for further research

• Search terms: “Alcor AU6987AN SC708AN mass production tool,” “H2testw full verify,” “F3write F3read,” “chip‑off NAND recovery Alcor.”
• Topics worth reading: ONFI parameter page interpretation, Alcor controller translation layers, endurance behavior of QLC vs. TLC under small‑file workloads.

Brief summary

• The device’s controller enumerates, but the NAND does not: E7FFFFFFFFFF is an invalid/failed ID, consistent with dead or disconnected flash.
• If you need the data, stop and consult a professional lab; controller‑level fixes will erase data.
• If you don’t need the data, you can try the Alcor MP tool to re‑initialize; validate with a full write/verify test. Expect failure or reduced capacity; replacement is the practical solution.

If you share your exact symptom (capacity shown, mount status, errors like “write‑protected” or “cannot format,” and whether data needs recovery), I can provide a step‑by‑step plan tailored to your OS and to this AU6987AN/SC708AN controller.

Disclaimer: The responses provided by artificial intelligence (language model) may be inaccurate and misleading. Elektroda is not responsible for the accuracy, reliability, or completeness of the presented information. All responses should be verified by the user.