Hifonics Service manual / schematic - Page 3

Petesaguy · 10th May 2006, 06:22 AM

Hello, this is my first post here, so if my etiquette is out of line please let me know.

I also am glad to see you here Stephen, just tripped across this site when researching what my chances are of resurrecting this amp. It was idle for about 10 yrs and recently (6 months) put back to use.

Unfortunately after returning to my vehicle after a short stop recently I turned on the head unit and no sound. I proceeded to verify the turn on voltage and troubleshoot. Found that the red diagnostic light was on and would only turn off if the rca input connections were removed.

I have tried reflowing the solder on the softstart circuit board hoping for a quick easy fix, but alas, no luck. Just wondering if this scenario suggests anything obvious, or what is the most logical approach for repair on the unit.

Any help from one and all would be greatly appreciated. thx

PS, will be posting this amp on ampguts as I don't see it there yet. This is for anyone else that may own or like to own this gem. (pardon the pun)

sdoom · 10th May 2006, 03:22 PM

Hi Petesaguy ,

did you make sure that it´s not the headunit causing the problem ?

Does the amp behave the same when you use a portable CD-Player instead the headunit ?

Petesaguy · 10th May 2006, 10:26 PM

Head unit appears to be ok. It has three pre-amp rca outs. Mids and sub are to the hifonics and the highs to the tweets on a separate amp.

The tweeters still work fine.

Also the power light does not come on when speaker and rca leads are all disconnected. this leads me to think initially that the turn on circuit may be the problem. Have not delved futher yet for anything other than to confirm that there are no smoked components.

Will be looking into which components on that circuit are available in the next little while.

Thx Peter

Cal Weldon · 10th May 2006, 10:29 PM

Hi Peter,

I don't have an answer to your question but I do like the creativity in your name. Do you deliver?

Petesaguy · 11th May 2006, 12:37 AM

Don't worry, the reason I am the original owner of my hifonics amp is that I also am a speaker aholic, somewhat reformed over the years. But. still appreciate fidelity.

No room for the 15" subs in the house though, Wife would protest. thank goodness for well designed enclosures these days. Still have the old Hafler DH amp if I need to get some serious volume.

Pete

sdoom · 11th May 2006, 02:57 PM

Although the hifonics amps are good in assembling quality (at least they are way better than most of the korean stuff I´ve seen) resolder all parts on the curcuit board, a lot of problems can be caused by bad solder joints, especially in older amps.

Two years ago (when I was jobless ) I fixed a lot of broken amplifiers throughout all price ranges. Over the half of the amplifiers only had bad solder joints and didn´t need spare parts.

When looking for parts, also check capacitors for leaking, if you find capacitors with a "hump" replace them, they usually are bad or at least totally out of tolerance.

when you feed power to the remote terminal (no spk or rca connected) is there a current draw ? (always use some sort of power supply with a current limiter. Hifonics amps have high effiency SMPS, the idle current even in the bigger amps is usually less than 1A , that means small power supplies can drive the amp when the amp is idling or small music levels are used.)

Steph

Petesaguy · 12th May 2006, 12:09 AM

I will figure out what the basic logic on the turnon circuits is and then test the output. If that is all well I will follow your advice for a full scale solder reflow. I have done it on this board so far.

I will post the resultss for you pleasure with great Kudos if you insight is indeed the fix.

Next post with results.

Peter

scott-leanne · 13th May 2006, 07:59 PM

http://www.mouser.com/ has the mpsa12's in stock for 12 cents each. Don't know the shipping cost to overseas though.

scott-leanne · 13th May 2006, 08:05 PM

Stephen, have you seen this?? http://www.rockfordfosgate.com/produ...9&locale=en_US

Look at the weight under specs....

mikeks · 16th May 2006, 12:30 PM

Quote:

Originally posted by MOER
I am not a fan of Mosfets for audio...

Good Man!

Additionally, i would avoid 'tubes like the plague if i were you....After all, this is the 21st centuary, me old matey!

10th May 2006, 06:22 AM	#21
Petesaguy diyAudio Member Join Date: May 2006	Gemini vIII with turn on issue, Hello, this is my first post here, so if my etiquette is out of line please let me know. I also am glad to see you here Stephen, just tripped across this site when researching what my chances are of resurrecting this amp. It was idle for about 10 yrs and recently (6 months) put back to use. Unfortunately after returning to my vehicle after a short stop recently I turned on the head unit and no sound. I proceeded to verify the turn on voltage and troubleshoot. Found that the red diagnostic light was on and would only turn off if the rca input connections were removed. I have tried reflowing the solder on the softstart circuit board hoping for a quick easy fix, but alas, no luck. Just wondering if this scenario suggests anything obvious, or what is the most logical approach for repair on the unit. Any help from one and all would be greatly appreciated. thx PS, will be posting this amp on ampguts as I don't see it there yet. This is for anyone else that may own or like to own this gem. (pardon the pun)

10th May 2006, 10:26 PM	#23
Petesaguy diyAudio Member Join Date: May 2006	thanks for the reply sdoom Head unit appears to be ok. It has three pre-amp rca outs. Mids and sub are to the hifonics and the highs to the tweets on a separate amp. The tweeters still work fine. Also the power light does not come on when speaker and rca leads are all disconnected. this leads me to think initially that the turn on circuit may be the problem. Have not delved futher yet for anything other than to confirm that there are no smoked components. Will be looking into which components on that circuit are available in the next little while. Thx Peter

10th May 2006, 10:29 PM	#24
Cal Weldon Speakerholic diyAudio Moderator Join Date: Jan 2004 Location: British Columbia	Hi Peter, I don't have an answer to your question but I do like the creativity in your name. Do you deliver? __________________ Next stop: Margaritaville Some of Cal's stuff \| Cal Weldon Consulting

11th May 2006, 12:37 AM	#25
Petesaguy diyAudio Member Join Date: May 2006	Hey Cal, thanks Don't worry, the reason I am the original owner of my hifonics amp is that I also am a speaker aholic, somewhat reformed over the years. But. still appreciate fidelity. No room for the 15" subs in the house though, Wife would protest. thank goodness for well designed enclosures these days. Still have the old Hafler DH amp if I need to get some serious volume. Pete

12th May 2006, 12:09 AM	#27
Petesaguy diyAudio Member Join Date: May 2006	Thanks sdoom, sounds like a good place to start. I will figure out what the basic logic on the turnon circuits is and then test the output. If that is all well I will follow your advice for a full scale solder reflow. I have done it on this board so far. I will post the resultss for you pleasure with great Kudos if you insight is indeed the fix. Next post with results. Peter


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10th May 2006, 03:22 PM	#22
sdoom diyAudio Member Join Date: Mar 2004 Location: Heidelberg	Hi Petesaguy , did you make sure that it´s not the headunit causing the problem ? Does the amp behave the same when you use a portable CD-Player instead the headunit ?

11th May 2006, 02:57 PM	#26
sdoom diyAudio Member Join Date: Mar 2004 Location: Heidelberg	Although the hifonics amps are good in assembling quality (at least they are way better than most of the korean stuff I´ve seen) resolder all parts on the curcuit board, a lot of problems can be caused by bad solder joints, especially in older amps. Two years ago (when I was jobless ) I fixed a lot of broken amplifiers throughout all price ranges. Over the half of the amplifiers only had bad solder joints and didn´t need spare parts. When looking for parts, also check capacitors for leaking, if you find capacitors with a "hump" replace them, they usually are bad or at least totally out of tolerance. when you feed power to the remote terminal (no spk or rca connected) is there a current draw ? (always use some sort of power supply with a current limiter. Hifonics amps have high effiency SMPS, the idle current even in the bigger amps is usually less than 1A , that means small power supplies can drive the amp when the amp is idling or small music levels are used.) Steph

13th May 2006, 07:59 PM	#28
scott-leanne diyAudio Member Join Date: Mar 2006 Location: Illinois	http://www.mouser.com/ has the mpsa12's in stock for 12 cents each. Don't know the shipping cost to overseas though.

13th May 2006, 08:05 PM	#29
scott-leanne diyAudio Member Join Date: Mar 2006 Location: Illinois	Stephen, have you seen this?? http://www.rockfordfosgate.com/produ...9&locale=en_US Look at the weight under specs....

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