Blown 20watt 4.7uf on soft start board

ben62670 · 25th June 2007, 05:01 AM

I blew the 3 of the 4 speaker out fuses with my Polk SDA speakers when hooking it up blindly. I realized my mistake, but wanted to finish my listening session. So I stuck 2 15a, and a 20a fuse in. Fix the speaker wiring. Turned it on, and poof. I looked for damage, and found none. So I busted out my mm found power on the soft start board. Unplugged it. Started testing resistors. The big 20watt 4.7uf was open. Took a hammer to it. Found the burnt spot. I am scared to just replace the resistor( I have 2 10ohm 10watt resistors). I don't want to blow anything else. What caused the resistor to blow after installing the speaker fuses?
Should I raplace the rail fuses, and give it a go with 5ampers instead of 10ampers?
Thanks Ben

Greg Erskine · 25th June 2007, 05:49 AM

Hi Ben,

Sorry to hear about your problems, but I think you need to take it to a professional before you do more damage to it, or yourself.

regards

djk · 25th June 2007, 09:27 AM

Polk SDA speakers will blow up mono-bloc and bridge output amplifiers.

This includes dual-mono amps like the Adcom GFA555.

SY · 25th June 2007, 02:03 PM

Quote:

This includes dual-mono amps like the Adcom GFA555.

For bridged I can see trouble in a common-ground wiring, but why dual mono? I've had a 555 for years and hooked it to all sorts of wiring schemes (including common-ground) with no problem whatever.

ben62670 · 26th June 2007, 05:29 AM

Killed this thread, and started another. Due to lack of sleep I rated a 4.7 ohm resitor a 4.7uf. I gotta watch stuff like that

25th June 2007, 05:01 AM	#1
ben62670 diyAudio Member Join Date: Dec 2006	Blown 20watt 4.7uf on soft start board I blew the 3 of the 4 speaker out fuses with my Polk SDA speakers when hooking it up blindly. I realized my mistake, but wanted to finish my listening session. So I stuck 2 15a, and a 20a fuse in. Fix the speaker wiring. Turned it on, and poof. I looked for damage, and found none. So I busted out my mm found power on the soft start board. Unplugged it. Started testing resistors. The big 20watt 4.7uf was open. Took a hammer to it. Found the burnt spot. I am scared to just replace the resistor( I have 2 10ohm 10watt resistors). I don't want to blow anything else. What caused the resistor to blow after installing the speaker fuses? Should I raplace the rail fuses, and give it a go with 5ampers instead of 10ampers? Thanks Ben

25th June 2007, 05:49 AM	#2
Greg Erskine diyAudio Member Join Date: Jan 2002 Location: Sydney/Australia	Hi Ben, Sorry to hear about your problems, but I think you need to take it to a professional before you do more damage to it, or yourself. regards __________________ Greg Erskine

25th June 2007, 09:27 AM	#3
djk diyAudio Member Join Date: Feb 2001 Location: USA	Polk SDA speakers will blow up mono-bloc and bridge output amplifiers. This includes dual-mono amps like the Adcom GFA555. __________________ Candidates for the Darwin Award should not read this author.

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26th June 2007, 05:29 AM	#5
ben62670 diyAudio Member Join Date: Dec 2006	Killed this thread, and started another. Due to lack of sleep I rated a 4.7 ohm resitor a 4.7uf. I gotta watch stuff like that

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