Curated from EEVblog forums, Elektor Magazine, YouTube reviews, blogs, and user communities.
62 issues documented across firmware, oscilloscope, signal generator, multimeter, and UI categories. 35 are critical or high severity. These inform the priorities for custom firmware development.
- Fix hang/lockup bugs (#1, #2, #7) — the #1 reason users are frustrated
- Fix flash filesystem corruption (#3) — proper FatFS mutex protection
- Make FFT actually work (#6) — listed feature that doesn't produce usable results
- Restore 1MHz signal generator (#11) — biggest regression vs predecessor
- Add min/max/avg reset (#9, #10) — easy win, frequently requested
- Fix signal generator accuracy (#5, #14) — wrong frequencies below 20Hz, visible steps
Issue #1 confirms the external SPI flash chip is a Winbond W25Q128JVSQ (128Mbit = 16MB). This is much larger than initially estimated — plenty of space for modules, waveform references, vehicle definitions, and other data.
The flash stores both firmware data and system graphics. A firmware update alone is not sufficient to restore a corrupted device — the external flash contents must also be restored.
| # | Issue | Source |
|---|---|---|
| 1 | Auto-measurement hang — long-pressing auto starts calibration with no escape; device must drain battery to recover | EEVblog (ee00) |
| 2 | GUI lockup on vertical position — freezes when adjusting V-pos with probes connected; worsens when ground clips touch | EEVblog (Rainwater) |
| 3 | Flash filesystem corruption — corrupts user storage (Drive 2) and system graphics (Drive 3), causing "Save failed" errors and missing display elements | EEVblog (Dr. Blast) |
| # | Issue | Source |
|---|---|---|
| 4 | Generator output depends on battery voltage — DAC appears tied directly to Vbatt with no reference; at half charge, full 3.3V output is impossible | EEVblog / Reddit |
| 5 | Signal generator inaccurate below 20Hz — DDS produces wrong frequencies at low end; some values output entirely different frequencies | EEVblog (Rainwater) |
| 6 | FFT/spectrum analysis non-functional — listed feature doesn't produce usable results | EEVblog (tutochkin) |
| 7 | Unexpected restarts on AUTO button — device reboots/freezes during normal scope use | OneSDR Review |
| 8 | Firmware update failures — some Amazon units stuck on old versions, refuse to run past v1.0.3 | EEVblog |
| # | Issue | Type | Source |
|---|---|---|---|
| 9 | DMM average can't be reset — no way to reset the running average without exiting and re-entering measurement mode | Feature Request | Community (multiple) |
| 10 | No min/max hold reset — min/max values accumulate over entire session with no reset option | Feature Request | Community (multiple) |
| 11 | Generator frequency reduced to 50kHz — was 1MHz on predecessor 2C23T; biggest community complaint | Regression | Elektor Review |
| 12 | Generator output is unipolar only — no output capacitor or symmetrical supply; can't generate bipolar signals | Complaint | Elektor Review |
| 13 | Generator max voltage reduced — from 3.3V to 3V p-p vs predecessor | Regression | Elektor Review |
| 14 | Generator sine wave shows visible steps/flattening — unsuitable for high-quality signal applications | Complaint | Elektor Review |
| 15 | Pause + timebase change doesn't update display — frozen waveform persists regardless of timebase changes | Bug | EEVblog (tutochkin) |
| 16 | Trigger position inconsistent — front edge not always centered on screen for single-shot captures | Bug | EEVblog (tutochkin) |
| 17 | Storage depth limited to ~1k points — possible reduction from predecessor's 32KB | Complaint | EEVblog |
| 18 | Input stage nonlinearity — amplitude increases slightly from 10MHz to 50MHz | Bug | Elektor Review |
| # | Issue | Source |
|---|---|---|
| 19 | Screen too crowded with multiple measurements displayed | Elektor Review |
| 20 | Counter-intuitive navigation — button functions change between modes; settings only accessible from startup screen | Audio Investigations Blog |
| 21 | Language selection confusion — accidentally selecting Chinese makes device nearly unusable; requires right-arrow (not down) to switch back | Audio Investigations Blog |
| 22 | Manual is tiny and nearly unreadable — online version described as "not very useful" either | Audio Investigations Blog |
| 23 | Long-press auto button has no warning — silently starts calibration, leading to unintended hangs | EEVblog (ee00) |
| # | Issue | Source |
|---|---|---|
| 24 | BNC connectors too close — probes with plastic covers can't both fit simultaneously | Elektor Review |
| 25 | Multimeter socket spacing non-standard — slightly less than 19mm, incompatible with some accessories | Elektor Review |
| 26 | Difficult to disassemble — rubber gasket appears permanently bonded; only reset pinhole accessible | EEVblog (ee00) |
The FNIRSI 1013D open-source firmware project is a community-developed replacement for a similar FNIRSI oscilloscope (FPGA+ARM+ADC architecture). It addressed display compatibility, touch calibration, and RMS measurement improvements — a useful reference for the 2C53T firmware rewrite.