bk st-140 burned resistors

shahsmerdis · 20th November 2011, 05:19 AM

Hello, Im new here so forgive me, say something stupid.

When i was setting up my BK-140 For the first time(buying them second hand) the magic smoke came out of the amplifier. triple checking my connections and talking to a few people, i have assumed that my connections are right and some reason it blew. When i opened it up i noticed that 1 of the resistors was burnt.
What would be the best course of action? The circuit board is burnt as well.

Should i just replace the resistor and try it again? the left speaker fuse blew, so i hope there aren't more things wrong with it. Are there certain steps i can follow to repair the amplifier. I would rather avoid spending money for someone else to fix this when it can be fixed for a few bucks.

Thank you in advance
-Shah Smerdis

ouimetnick · 1st December 2011, 05:17 PM

Resistors burn for a reason. Fix the issue, or the replacement resistor will also burn up.

Mooly · 1st December 2011, 06:09 PM

Do not connect speakers as any DC offset will damage them.

Use a bulb tester to work on the amp non destructively. Check the basics such as output transistors/drivers and associated components.

You almost certainly need the circuit to fix this.

20th November 2011, 05:19 AM	#1
shahsmerdis diyAudio Member Join Date: Nov 2011	bk st-140 burned resistors Hello, Im new here so forgive me, say something stupid. When i was setting up my BK-140 For the first time(buying them second hand) the magic smoke came out of the amplifier. triple checking my connections and talking to a few people, i have assumed that my connections are right and some reason it blew. When i opened it up i noticed that 1 of the resistors was burnt. What would be the best course of action? The circuit board is burnt as well. Should i just replace the resistor and try it again? the left speaker fuse blew, so i hope there aren't more things wrong with it. Are there certain steps i can follow to repair the amplifier. I would rather avoid spending money for someone else to fix this when it can be fixed for a few bucks. Thank you in advance -Shah Smerdis

1st December 2011, 06:09 PM	#3
Mooly diyAudio Member Join Date: Sep 2007	Do not connect speakers as any DC offset will damage them. Use a bulb tester to work on the amp non destructively. Check the basics such as output transistors/drivers and associated components. You almost certainly need the circuit to fix this. __________________ ------------------------------------------------------- *A simulation free zone.* *Design it, build it, test it.*

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Help me pls with B&K st-140	tony Ma	Solid State	3	5th May 2012 03:03 PM
BK st 140	evanc	Swap Meet	0	10th April 2011 02:19 PM
B&K ST-140 Check-out Upon Power Up	Falcon	Solid State	3	22nd February 2010 08:27 PM
Perform Biasing on B&K ST-140	Falcon	Solid State	2	6th February 2010 04:59 AM
Looking for pn4889 for a B&K st-140	jwv3	Solid State	2	10th February 2004 07:02 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

1st December 2011, 05:17 PM	#2
ouimetnick diyAudio Member Join Date: May 2011 Location: Beverly, Massachusetts, USA	Resistors burn for a reason. Fix the issue, or the replacement resistor will also burn up.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)