Typical faults by mainboard family: how to use the faults database
Many TV faults repeat on the same board. A boot loop on one Samsung chassis, a backlight failure on one Vestel supply, a bad flat cable on one Philips board: once you have seen it a few times, you recognise it. The faults database in FW Tool collects such reports so you do not have to search forums for each job.
Part of the Boards and faults guide.
What the database is, and what it is not
The data is gathered from open forums and service sites, not from manufacturer documentation. Each entry has a board and brand, a TV model list, a symptom, a probable cause, what was done about it, and links to the sources. The program labels the whole tab UNVERIFIED for that reason. Treat an entry as a lead to check, not as a verdict.
Safety. Many of these faults sit in the power supply or LED driver. Mains and backlight voltages are dangerous: isolate the set, discharge capacitors, and never touch the primary side while powered. One entry in the sample data even mentions LED output of 85-100 V.
Confirmed and single-source
Every fault carries a confidence mark. “Confirmed” means more than one source describes it. Anything else is shown with a red “one source” warning. In the sample set (10 faults on 6 boards) seven are confirmed and three are single-source reports. Two examples of single-source entries:
- A Philips QFU1.2E board with no picture after a processor repair, attributed to a faulty 51-pin cable between mainboard and T-con. One forum thread reports it, so it is a single-source report.
- A Sony board (1-894-595-12) with a picture and backlight missing after an eMMC replacement, attributed to a dump from a different model size. Again a single-source report.
Examples from the sample data
The free version shows examples only. The list below is a sample, not the full database.
- Samsung BN41-01660A/B (UE40D5500 and related models). Endless reboot loop with the Samsung logo, restarting every few seconds. Reported cause: a failed or corrupted NAND flash (IC1302), often after an online firmware upgrade. Reported fix: replace it with a NAND programmed with a board-specific dump. Replacing the EEPROM alone is reported not to help. Confirmed.
- Sony 1-894-595-12 (KD-49X8305C / 8309C). Stuck on the logo or in an Android boot loop; reported cause is a damaged eMMC, fixed by replacing it and programming the correct dump. Confirmed.
- Philips QFU1.2E. No start with the standby LED blinking twice; reported cause is loose BGA solder on the processor with poor cooling. Confirmed.
- Panasonic TNP4G549 / TNP4G568. Backlight flashes briefly and the set shuts down; reported cause is damaged LED strips. Confirmed.
- TCL Roku TV boards. A logo flash followed by black, or sound with a black screen. Reports point at the mainboard in one case and at LED strips in another, so check the supply and backlight before replacing the board. Confirmed.
- Vestel 17MB95 + 17IPS71. Sound and menu but no backlight, often an open LED in a strip. A second entry, a power supply with no outputs after a bang and a damaged primary MOSFET, is a single-source report where the repair was not confirmed.
How to use an entry well
- Match the board name or the model, not only the brand.
- Compare the symptom word for word with your set.
- Do the measurement that would prove the cause before you order parts.
- For flash or eMMC causes, a dump taken from the same model is essential, not one from a similar-looking set. See choosing an eMMC replacement.
- Follow the listed source to read the whole discussion.
Typical mistakes
- Treating a single-source entry as established fact.
- Matching on the TV size or brand only, when the chassis differs.
- Replacing an expensive part because a symptom resembles an entry, without checking the power supply first. Start with the standby checks if the set is dead.
- Writing a wrong dump to a replacement memory.
How this is done in FW Tool
- The reference has a “Faults by board” tab. A search field filters by board, TV model, brand or symptom, and a counter shows how many boards match.
- Each result shows the symptom, cause, fix and source links, and single-source entries are marked.
- The free version shows the sample boards. The licensed version loads the full database over the internet, so it needs a connection.
- Results of your own repairs go in the repair log, which flags when you have already repaired the same model. See the repair log.
More about the program is on the features page.
FAQ
Is the database complete?
No. It reflects what was reported publicly. If your board is not listed, that says nothing about whether it has a known fault.
Why are there Russian and English texts?
The records carry text in both languages. The program shows the one matching the interface language.
Can I rely on a confirmed fix?
Confirmed means more than one source agrees, not that it will work on your set. Check against the service manual.