ok i have two 10 inch infinity references......a 620 watt power acoustik amp.....1.5 farad capacitor.........has been running fine and bumping hard to my standards.....but the other day i took my box out just for a little bit to mess with something in my backseat.......i put it back in........hook the subs back up and turn the stereo on and all the subs are putting out is a thump....thump...thump.........have no idea what this could be.....never experienced it, help very much appreciated
Replies (10)
swez on 05/16/2007 22:52:56
Hum, in this case, I think I would reboot the amp and recharge the cap.
1. Disconnect the main power line fuse to the amp
2. Disconnect the RCA's from the amp
3. Check the ground cable on amp
4. Reconnect amp power line, ground and REM
5. Discharge and then Recharge cap again
6. Reconnect your RCA's from HU
Now, try again and see what happens.
Good luck,
Swez
jj42 on 05/16/2007 23:30:34
I just did........same thing. all the connections are good....nothings touching, the ground is straight to the body and its clean.....its just a constant thump thump from the subs.....the higher i turn the amp up the louder it gets......i can have the volume set on 1 and the subs will just thump continuously.....i have no idea whats wrong
trunkisloud on 05/17/2007 01:23:22
is your amp mounted to directly to the car ?? i.e. screwed to the metal? i think i did this once and that was the problem....try takin the cap outta the picture.....trace your rca's to make sure they didnt get pinched during the back seat project...
jj42 on 05/17/2007 13:32:31
no it is sitting on the carpet.......i just took the capacitor out and wired up the amp .....checked the RCA and they're good.......still doing the same thing
jj42 on 05/17/2007 13:37:36
oh ya forgot to mention i have an Alpine head unit......stock door speakers
swez on 05/17/2007 17:26:48
Well sir, you have our curiosity going now. We do see this one from time to time and the earlier suggestions usually cure it.
If you disconnect the RCA's from the amp, does the noise go away?
Swez
jj42 on 05/17/2007 20:07:57
no......matter of fact if i have the RCA's plugged in it reduces it.....once i unplug them the noise is worse and continues to get worse as i turn the amp level up as opposed to being less loud when they are plugged in
swez on 05/18/2007 06:37:49
Hum, this sounds like the amp has internal problems with the power supply or damaged RCA signal input jacks.
How old is this amp anyway?
If you elected to have it repaired, figure about $60.00 bench fees plus parts and labor. If one is a curious type, remove the amp from the vehicle, pull off the covers and have a good look inside. You may find something simple, (Loose solder joints) or something more serious. (Burned circuit board or smoked components)
Swez
jj42 on 05/18/2007 09:02:06
this amp is about 5 months old or so............ya i may pull it apart myself and juss fiddle with it......sounds like its pretty much fried anyway so if i mess it up more cant hurt much
swez on 05/18/2007 19:42:22
If you have a warranty, try that route first. If not, poking around inside is a good way to learn how amps are made. Make a diagram of all key wiring harnesses and where they go on the amps' PC board. I often use masking tape lables to ID each harness and location it belongs to. Can use colors, numbers or letters to ID each harness and the right spot on the board they came from.
Tech Tip #1: Most amps have storage caps inside that store energy even when the amp is disconnected. To be safe from accidental bites from them, discharge the caps first. A simple 12 volt tail lamp bulb with some wires attached is a good tool for discharging caps safely. Just make sure you don't touch the bare wires when discharging caps. In most cases, the caps will discharge in a matter of seconds. When the lamp goes dark, the caps are discharged.
Tech Tip #2: When inspecting PC boards, it's good to have a strong lamp to backlight the board. (Component side) Then, a good magnifying glass to look carefully for blown circuit traces, grainy solder joints, (Cold solder joints) and other annomolies on the soldered side of the board. A good "Sharpie" pen is good for marking potential trouble spots.
If you have a good digital camera handy, take clear pictures and post them to photobucket.com. This will give us a chance to view what you see and point out potential problem areas to work on.
Swez
PS If you want to get a quick peak at what you may find inside this amp, have a look at this site, find your amp model # and then click on it to see what it looks like:
http://ampguts.realmofexcursion.com/
http://ampguts.realmofexcursion.com/Power_Acoustik_LT480-2/
Replies (10)
swez on 05/16/2007 22:52:56
Hum, in this case, I think I would reboot the amp and recharge the cap.
1. Disconnect the main power line fuse to the amp
2. Disconnect the RCA's from the amp
3. Check the ground cable on amp
4. Reconnect amp power line, ground and REM
5. Discharge and then Recharge cap again
6. Reconnect your RCA's from HU
Now, try again and see what happens.
Good luck,
Swez
jj42 on 05/16/2007 23:30:34
I just did........same thing. all the connections are good....nothings touching, the ground is straight to the body and its clean.....its just a constant thump thump from the subs.....the higher i turn the amp up the louder it gets......i can have the volume set on 1 and the subs will just thump continuously.....i have no idea whats wrong
trunkisloud on 05/17/2007 01:23:22
is your amp mounted to directly to the car ?? i.e. screwed to the metal? i think i did this once and that was the problem....try takin the cap outta the picture.....trace your rca's to make sure they didnt get pinched during the back seat project...
jj42 on 05/17/2007 13:32:31
no it is sitting on the carpet.......i just took the capacitor out and wired up the amp .....checked the RCA and they're good.......still doing the same thing
jj42 on 05/17/2007 13:37:36
oh ya forgot to mention i have an Alpine head unit......stock door speakers
swez on 05/17/2007 17:26:48
Well sir, you have our curiosity going now. We do see this one from time to time and the earlier suggestions usually cure it.
If you disconnect the RCA's from the amp, does the noise go away?
Swez
jj42 on 05/17/2007 20:07:57
no......matter of fact if i have the RCA's plugged in it reduces it.....once i unplug them the noise is worse and continues to get worse as i turn the amp level up as opposed to being less loud when they are plugged in
swez on 05/18/2007 06:37:49
Hum, this sounds like the amp has internal problems with the power supply or damaged RCA signal input jacks.
How old is this amp anyway?
If you elected to have it repaired, figure about $60.00 bench fees plus parts and labor. If one is a curious type, remove the amp from the vehicle, pull off the covers and have a good look inside. You may find something simple, (Loose solder joints) or something more serious. (Burned circuit board or smoked components)
Swez
jj42 on 05/18/2007 09:02:06
this amp is about 5 months old or so............ya i may pull it apart myself and juss fiddle with it......sounds like its pretty much fried anyway so if i mess it up more cant hurt much
swez on 05/18/2007 19:42:22
If you have a warranty, try that route first. If not, poking around inside is a good way to learn how amps are made. Make a diagram of all key wiring harnesses and where they go on the amps' PC board. I often use masking tape lables to ID each harness and location it belongs to. Can use colors, numbers or letters to ID each harness and the right spot on the board they came from.
Tech Tip #1: Most amps have storage caps inside that store energy even when the amp is disconnected. To be safe from accidental bites from them, discharge the caps first. A simple 12 volt tail lamp bulb with some wires attached is a good tool for discharging caps safely. Just make sure you don't touch the bare wires when discharging caps. In most cases, the caps will discharge in a matter of seconds. When the lamp goes dark, the caps are discharged.
Tech Tip #2: When inspecting PC boards, it's good to have a strong lamp to backlight the board. (Component side) Then, a good magnifying glass to look carefully for blown circuit traces, grainy solder joints, (Cold solder joints) and other annomolies on the soldered side of the board. A good "Sharpie" pen is good for marking potential trouble spots.
If you have a good digital camera handy, take clear pictures and post them to photobucket.com. This will give us a chance to view what you see and point out potential problem areas to work on.
Swez
PS If you want to get a quick peak at what you may find inside this amp, have a look at this site, find your amp model # and then click on it to see what it looks like:
http://ampguts.realmofexcursion.com/
http://ampguts.realmofexcursion.com/Power_Acoustik_LT480-2/
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