CurtPalme.com Home Theater Forum

AFryia · Posted: Fri Sep 20, 2013 1:33 am Post subject: ButtKicker Amp Issue

I have a BKA1000-4A ButtKicker amp that blows the AC line fuse instantly after plugging it in. There are no obvious signs of component failure. The thing looks brand new inside.

I bought it in late 2005 so either I fix it or pitch it.

Anyone else have problems with this amp. Were you able to fix it?

**Curt Palme** · Posted: Fri Sep 20, 2013 3:09 am Post subject:

I know nothing about the construction about the buttkicker amp, but if it's an analog design, if you're lucky, the bridge rectifier has shorted.

If it's one of the new switching power supply designs like most of them are, it will be a bitch to fix, and you're better sending it off to buttkicker.

Post a pic of the component side of the amp module.

BTW, it's really rare for a solid state component to show 'signs' of issues. gone are the days of blown resistors and components smoked off the board as the switching power supply shuts down the second it senses a dead short.

AFryia · Posted: Mon Sep 23, 2013 10:56 pm Post subject:

Curt,

It is classified as a mono-block digital switching amp. Not sure what that means but i sure has a big ass toroid in it.

Somewhere I read BK does not service out of warranty product So I emailed them and they are sending me the electrical schematics.

**Curt Palme** · Posted: Mon Sep 23, 2013 11:06 pm Post subject:

First comment: What sh*t construction. Sad

Here's what to do: Get another fuse, disconnect all the large connectors on that amplifier board with the two large coils on it. (last pix).

Power it back up with a new fuse. If the fuse is OK, then you're probably screwed, as switching amps are hard to fix, and you probably have more than just blown output transistors shorted. (the ones on the heatsink).

if the fuse still blows when the power amp is disconnected, then you hopefully lucked out, and just the bridge rectifier has shorted. IN some Made in China/taiwan stuff, that's pretty common. The bridge rectifier is the gray square thing under the wires on the top right board. Any good electronics place will have that, and with the board out, you'd measure a dead short between two of the 4 legs of the rectifier.

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Mac told me to pass this on, and to note the parts in the picture Wink

AFryia · Posted: Tue Sep 24, 2013 10:48 pm Post subject:

AFryia · Posted: Sun Dec 29, 2013 11:58 pm Post subject:

[quote="AFryia"]

Jeremy112 · Joined: 28 Sep 2006 Posts: 2649 Location: Fond du Lac, WI

Hey Nash, I got a good question for ya,

When is the last time you spoke to macguyver? I haven't seen him on here and honestly I miss the guy like a family member! I've just been curious if he is okay or decided to take a hiatus from here Razz

Sorry for hijacking the topic AFriya

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

he posted here today as a matter of fact.

Wink

Nashou

Jeremy112 · Joined: 28 Sep 2006 Posts: 2649 Location: Fond du Lac, WI

AFryia · Posted: Thu Mar 13, 2014 11:43 pm Post subject:

Can anyone help identify this capacitor. At least I think it is one, the silk screen says it is.

The two brown oblong caps on the rail near the power transistors/heat sink. The only markings are "100K 400V" 400 volts I kinda get but what size? Is it 100K pico fard?

ecrabb · Posted: Fri Mar 14, 2014 12:15 am Post subject:

See, this is why I hate electronics. It makes me feel dumb because you just have to "know stuff". Wink

You look up a page like this:
http://www.4crawler.com/Diesel/CheapTricks/Tachometer/Capacitor.html

Oh, so the first two digits is the capacitance in pF, and the third digit is multiplier, i.e. the number of zeroes. K is the tolerance, 10 percent. Cool, so it's 10pF, with 0 zeros. 10pF is 0.00001uF. Crap. Can't be that. Yeah, 100k pF is .1uF, which is probably about right, but then WTF is the tolerance?

Never mind. Can't figure it out on my own. Have to ask Mac or Curt because it's now impossible to figure out on my own. Grrrrr…

SC

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

It is a 100000 picofarad film capacitor, or 100nf or .1 uf.

and lower tolerance is always better in most cases.

nashou

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

Or is it 10pf, +/- 10%

AFryia · Posted: Fri Mar 14, 2014 10:32 pm Post subject:

AFryia · Posted: Fri Mar 14, 2014 10:37 pm Post subject:

I hope this chart is right.

http://www.turretboards.com/capacitor_conversion_chart.htm

**Curt Palme** · Posted: Sat Mar 15, 2014 9:44 pm Post subject:

I hate to say this, but caps like that are NEVER the issue. Not unless one has the side blown out of it, and in transistor circuits, that's rare.

Most likely suspects are semiconductors, then electrolytic caps, then resistors, then other stuff. Not sure of the exact numbers, but I'd say the semis and caps count for 95% of failures, and resistors typically only change values or blow because a cap has shorted or a semi has failed.

AFryia · Posted: Sun Mar 16, 2014 11:41 pm Post subject:

**Curt Palme** · Posted: Mon Mar 17, 2014 10:34 pm Post subject:

Sorta, kinda! You can test for dead shorts with them in the circuit, those will be easy to find, but partially shorted/leaky ones, especially those with very high resistance leakage is almost impossible to tell in circuit.

Yep, if the caps are bubbled, change them all.

AFryia · Posted: Wed Mar 26, 2014 11:53 pm Post subject:

Is my test method correct for a N-Channel FET;

meter set to diode check/continuity (2Kohm).

S>G and D>G high resistance
G>S and G>D low resistance

S>D low resistance (spec sheet says 0.075ohm)

By my account 2 are shorted 6 are open. What are the odds of all 8 FET's roasting?