EEVblog 1520 - Troubleshooting a Faulty BM786 Multimeter

• #50 Reply
  Posted by Kean on 25 Mar, 2023 07:42
• Quote from: Jeeper44 on 25 Mar, 2023 01:04

  Around the 2:54 mark in the second video, 1522, you mention a content creator who has multi-series troubleshooting videos. Can you share that name again. I've tried searching based on what I think you said but haven't found them. This was right after mentioning Joe Smith.
  

  
  That would be Defpom
  https://www.youtube.com/channel/UCllpBTH26_dAl5tYl7vA1TQ
• #51 Reply
  Posted by NoMoreMagicSmoke on 21 May, 2023 05:21
• Quote from: EEVblog on 07 Jan, 2023 22:36

  And there is a history of BM235 chips just failing.
  

  
  Is this an issue specific to the BM235 chipset? Or is it a problem with the Hycontek processors in general? Have you seen many failures in the BM786 related to the processor?
• #52 Reply
  Posted by EEVblog on 21 May, 2023 06:15
• Quote from: NoMoreMagicSmoke on 21 May, 2023 05:21

  Quote from: EEVblog on 07 Jan, 2023 22:36

  And there is a history of BM235 chips just failing.
  

  Is this an issue specific to the BM235 chipset? Or is it a problem with the Hycontek processors in general? Have you seen many failures in the BM786 related to the processor?
  

  
  There have been odd failures were the chipset appears to be the culprit, but not confirmed by Brymen.
• #53 Reply
  Posted by Phil_A on 18 Nov, 2023 04:36
• I just saw this video.  I think the U1 "microcontroller" you are pointing to is actually the HY3131 DMM front end (48 pin).  The NCs pins seem to line up.   The pins you pointed to are AGND, REFO and VSSA on the front-end. The location of Xin/Xout seem correct and the HY3131 spec sheet specifies that 4.9152 Mhz Xtal.  Perhaps U16 (64 pin) next to the buzzer is the microcontroller?   Maybe U16 is a HY16F 32bit microcontroller? - Phil