I'm working on an active subwoofer made by Jamo. Subwoofer works normally but while in auto sleep mode it blows a fuse. I measured components off the PCB and only suspicious thing I found was this component. Between two adjacent legs it measured something around 70 ohms. When I removed the component from the board the corresponding solder pads' resistance went up to around 70 kilo ohms. I couldn't find any information from the internet.

I marked the component's place with a red arrow. The subwoofer is manufactured in year 2001 so it's an old component.

Whole circuit board. RCA input on right. enter image description hereClose up of area near the component.

Picture of the component.

  • \$\begingroup\$ Possibly BFQ31A transistor? \$\endgroup\$
    – jonathanjo
    Jul 12, 2023 at 18:38

1 Answer 1


The markings match with a Vishay SST175 JFET.

enter image description here

I found a picture of the part that shows the style of the markings matches:

enter image description here (Source: ebay.com)


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.