Bluetooth Remote Industrial Fan Repair.    Main IC Identification hunt? - Page 1
Forum section: electronics / repair

author: Zero_Ego
author_rank: Regular Contributor
timestamp: June 09, 2025, 10:50:26 pm
content: Hi,I have a bluetooth remote that I am trying to repair. I'm 99.9% sure that the problem is a bad solder join on the main IC - but I can't see it to solder it. (I'm waiting in a microscope)Out of curiosity - I was wondering what the IC might be? I have attached (2) two images as ALL identification have been erased.For size reference that bracket to the left is where the 3.6V CR2032 is mounted. (Coin cell)Does anyone recognize it please. Would it be a dedicated bluetooth IC or is it some programmed ICI would love to hunt down the datasheet and study it. Even clone it if I can for fun maybe.Thank you very much for reading.ZE

author: fzabkar
author_rank: Super Contributor
timestamp: June 10, 2025, 12:11:08 am
content: Is there an FCC ID on the label?

author: Zero_Ego
author_rank: Regular Contributor
timestamp: June 10, 2025, 06:30:14 am
content: Quote from: fzabkar on June 10, 2025, 12:11:08 amNo luck there. I went and had a good look on the PCB and the case no FCC.Great thought chasing the FCC ID.Thanks

author: Zero_Ego
author_rank: Regular Contributor
timestamp: June 10, 2025, 06:56:21 am
content: For education purposes I decided to upload the 2 images (above) into AI.it shot out a staggering amount of information, observations and possibilities.This really blew my mind.I'm sharing because it is astonishing! Judge for yourself what it got correct. ( I'm still working through it - that's a lot for a remote)I upload the same two images posted above and ask it the following."I have an bluetooth remote that I am trying to identify the main IC. The etchings have been removed so no one can ID the chip. I am looking at what it might probably be? Is it a dedicated bluetooth IC or something like an ARM? Can the crystal give any clues? I have include the images of the PCB"ChatGPT"Thanks for the clear photos. Here's a breakdown of what we can infer from the board and layout:Key Visual Features:1. Chip Package & Pin CountThe main IC is a 16-pin SOP/SOIC.Pins and routing suggest it's a microcontroller or RF SoC (system-on-chip).2. Antenna TraceThe PCB has a PCB antenna (top-right), clearly for 2.4 GHz RF — typical of Bluetooth or 2.4 GHz ISM band use.3. CrystalMarked “16.000” — that’s a 16 MHz crystal, a very common clock for:Bluetooth chips (e.g., Nordic, CSR/Qualcomm, Realtek, Beken, etc.)General-purpose MCUs like STM32, but less likely if used with this antenna.4. RF Matching ComponentsYou can see R1 (marked 222 = 2.2k) and a small pi network (C3, C4, L1) near the antenna — these are typical in Bluetooth or RF frontend tuning.Most Likely Candidates for the IC:Since the crystal is 16 MHz and there's a 2.4 GHz antenna, and given it's a remote:Most Probable:Beken BK3431Q or similar — used in budget Bluetooth remotes; SOP16 or QFN packages.EGBT-045MS / TYWE3S or small form-factor Bluetooth SoC modules (sometimes stripped from packaging and bonded directly).Nuvoton or Holtek HT32F series — if it’s a microcontroller with onboard 2.4GHz.Less Likely:Nordic nRF51822/52810 — usually QFN, not SOP-16, so not matching your chip.CSR chips (e.g., CSR8635) — usually have more pins and are QFN or BGA.Possible Identification Strategy:Trace the pins: Map which pins go to the crystal, antenna network, power, etc. Can hint at internal block configuration.Compare to datasheets: Look up BK3431Q, HT32F, or BLE SoCs in SOP-16 packages.Use a logic analyzer on the data pins (or oscilloscope) while pressing buttons — check if it’s sending serial, I2C, or proprietary RF bursts.Try FCC ID search: Some boards like this share layouts across brands, and a reverse image search or FCC database could lead to a datasheet or module name.Would you like help identifying pin functions using a continuity test and basic layout tracing?ChatGPT END.

author: Zero_Ego
author_rank: Regular Contributor
timestamp: June 10, 2025, 07:40:26 am
content: Admittedly this post should be in the beginners lounge.It's way over my head and I have NO way to accurately assess fact from fiction with the speed of a pro eyeballs.Please move the post if necessary.

author: Haenk
author_rank: Super Contributor
timestamp: June 10, 2025, 08:50:36 am
content: Even if you have to manually check the details, I find this answer pretty amazing.

author: Zero_Ego
author_rank: Regular Contributor
timestamp: June 10, 2025, 09:06:35 am
content: Quote from: Haenk on June 10, 2025, 08:50:36 amYes I am working my way through it. Can I ask a question please?If you look at L1 near the antenna (close up of LED image) it has a 0 (zero) on it.Doesn't this usually mean its a 0 Ohm resistor i.e a fuse (dead short)Do inductors have (0) written on them if so what value could this possibly be?I think its a resistor personally. Am I wrong or would the circuit not transmit without that inductor L1?Thanks

author: nali
author_rank: Frequent Contributor
timestamp: June 10, 2025, 10:22:36 am
content: Quote from: Zero_Ego on June 10, 2025, 09:06:35 amIt's a zero-ohm resistor. These things are often designed with provision for a pi or T filter in case the antenna needs matching. If it's "good enough" then a 0R link gets fitted inline and the parallel elements (C4 C5) are not fitted.

author: Haenk
author_rank: Super Contributor
timestamp: June 10, 2025, 10:47:58 am
content: Quote from: Zero_Ego on June 10, 2025, 09:06:35 amNever seen an inductor with "0" markings - 100% chance of being a jumper (0 R).

author: 2N3055
author_rank: Super Contributor
timestamp: June 10, 2025, 10:51:37 am
content: to me 16MHz oscillator looks like it is not soldered in right..