Hifonics BG 1900

[Doug777]

I have two Hifonics BG 1900 amps. One amp is powering a 15" Sundown SA v2 at 1 ohm. The other amp is powering two 12" Kicker L7s at 1 ohm. I tested volts to both amps, and I'm getting 14.7 volts. Checked RCA cables and all is good. The amps do power on. They aren't in protect mode either.

The thing is, sometimes they produce sound and sometimes they don't. They exhibit this behavior in tandem, that is, they either both work or they both don't work.

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[Doxquzme Premium Member]

Usually, that would indicate there is an issue with the source. I assume that there is a single RCA that feeds both? Disconnect and test without the amps hooked up. Get a 3.5mm to RCA, and plug a phone or laptop directly into each amp, one at a time. If they work fine with this source, then check the RCAs up the line, specifically the one that feeds the signal to the amps prior to any splits. If the amps are fed off the other component, check that connection too, and work your way up until you isolate the source.

 

[Doug777]

Thank you Doxquzme! I'll try those steps and will let you know.

 

[Doug777]

Usually, that would indicate there is an issue with the source. I assume that there is a single RCA that feeds both? Disconnect and test without the amps hooked up. Get a 3.5mm to RCA, and plug a phone or laptop directly into each amp, one at a time. If they work fine with this source, then check the RCAs up the line, specifically the one that feeds the signal to the amps prior to any splits. If the amps are fed off the other component, check that connection too, and work your way up until you isolate the source.

Hi Doxquzme,
I just tried using the RCAs from my mids and highs amp (JL Audio JD-400) and both Hifonics amps still don't work. I think that the amps are faulty.

 

[Doxquzme Premium Member]

Best $12 investment you'll make, even if you only use it a couple of times.

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Then watch this

If you have a digital multimeter, watch this and test your output from the amplifier.

 

[1aespinoza 10+ year member]

Hi Doxquzme,
I just tried using the RCAs from my mids and highs amp (JL Audio JD-400) and both Hifonics amps still don't work. I think that the amps are faulty.

Did you try wiggling the RCAs on the amp? The RCA jacks can sometimes develop hairline cracks in the solder joints and cause your issue.

 

[dragon.breath 10+ year member]

Is that 14.7 volt reading at the amplifiers? What kind of voltage do you get at the amplifiers when they are playing loud? How about when they cut off?

 

[Doxquzme Premium Member]

I think that he just needs to see if anything is coming off the terminals. The weird part is, that the initial post indicates that they both fail at the same time (which may have actually been one right after the other, wasn't there so...). That seems unlikely unless it's something that amps share, externally. OP indicates the RCA's to the JL powering mids and highs didn't get any output on the two sub amps either, so , think it has to be the amps, no?

 

[dragon.breath 10+ year member]

If both amps are grounded to the same point, a bad ground connection could be the issue. Same for the power side, a bad connection at the battery or fuse holder.

 

[Doug777]

Did you try wiggling the RCAs on the amp? The RCA jacks can sometimes develop hairline cracks in the solder joints and cause your issue.

I used different RCA cables, but I'll try and wiggle them to see if that helps. Thank you.

 

[Doug777]

If both amps are grounded to the same point, a bad ground connection could be the issue. Same for the power side, a bad connection at the battery or fuse holder.

I'm getting 14.7 volts to the amps. I have three amps going to a ground distribution block. One of the amps works, the other two monoblocks don't. I just installed a Mechman 400 Amp alternator and did a big four upgrade. I thought that would fix my issue, but it didn't.

 

[Doug777]

I think that he just needs to see if anything is coming off the terminals. The weird part is, that the initial post indicates that they both fail at the same time (which may have actually been one right after the other, wasn't there so...). That seems unlikely unless it's something that amps share, externally. OP indicates the RCA's to the JL powering mids and highs didn't get any output on the two sub amps either, so , think it has to be the amps, no?

I agree. I think the amps are toast. They're only a couple months old. I've read that Hifonics amps aren't what they used to be like back in the day.

 

[Doug777]

Is that 14.7 volt reading at the amplifiers? What kind of voltage do you get at the amplifiers when they are playing loud? How about when they cut off?

Yep, at the amplifiers. I get the same 14.7 volt reading when they cutoff too.