r 151 accent resistor burns

Discuss Yocto construction and related issues
  • National Semiconductor. I can't imagine TI would be an issue though.
  • Same here, it works on first try, but R151 is smelly and black now, and if I turn accent knob up it lowers master volume
    I think I am from the last batch but mine says 4011BE
    the sound of the rest is great
  • I will receive some UB and BE TI's 4011s on Tuesday-Wednesday and so will be able to change it. I will let you know if it well correct the problem.
  • Success!!!

    Maybe the problem was the heat applied to the chipset during the soldering because this time I put a socket between it and the PCB
  • I can also confirm that with the supplied CD4011BE chip for IC6 in the Accent section, R151 smoked and burnt. As recommended by keen I changed the chip to UB(E) version and now all is well. Solved 151 problem as well. The chip I put in is : Texas Instruments - CD4011UBE

    Thanks a bunch for the info.
    keen wrote:Hello franzkleid,

    I had same problem on 4th batch kit.
    Please try unbuffered 4011UB.
    I solved R151 problem by it.

    cheers
  • What's the batch production code of these malfuctioning ic's?
    It would be good to know so we can spot them in advance.
  • The batch/date code on the texas instrument CD4011BE that came in my yocto kit is 10HMAND. Hope that helps. cheers
  • Success,

    I had the same issue with R151. I also had a 4011BE from the 10HMAND batch. Replaced by a 4011UB and its rocking now.
  • I think it is a batch of bad chips. I was having similar problems such as Bass drum diassapearing when I tiurned the accent up and a few other weird things. My kit came with texas instrument CD4011BE code 10HMAND. I replaced it with a texas instruments CD4011BE that I had on hand and everything works. I did not have resistor burn.