jbl bp600.1 issue

audiobahnkid592 · 27th July 2008, 12:34 AM

when under full power and heavy bass the amp goes into protection for about 1 sec then comes back on and is fine for 15 up to 10 15 min before it will do it agian for another sec. any ideas?

Perry Babin · 27th July 2008, 02:31 AM

Does it ever cut off when you hit a bump?

Some amps have a problem with insufficient support for the boards and the legs on the transistors break at the body of the transistor. When this happens on the gate leg of the transistor, the vibration (from bass or from hitting bumps) can cause the gate leg to break its connection which will prevent the transistor from swithing off when it should. This can trigger the over-current protection circuit.

I'm assuming that you've checked the voltage across the B+/ground terminals and it's remaining near or above 12v.

audiobahnkid592 · 27th July 2008, 02:35 AM

It does it standing still in a parking lot so i dont think vibrations are causing it but will look at it and ive had other amps on the same power and ground wires with no issues but i will also check that

amc32 · 27th July 2008, 06:46 AM

Is the amp mounted on the enclosure?

audiobahnkid592 · 27th July 2008, 12:43 PM

a bit more back ground i just bought this amp and a jbl b80.4 for 130 for both of them locally through craigs list. now i tock the cover off the 600.1 and noticed the clamps to clamp the transistors to the heat sink were lose i tightened all of them and put it back to gether and it worked fine but that one problem i mentioned. Also it was mounted on the enclosure but was only on it for about 45 min. it was on a 1.25CF sealed box powering a audiobahn AW1200Q if that means anything.

audiobahnkid592 · 27th July 2008, 12:54 PM

No broken transistor legs but i found the top of one capcitor swelled could this be a porblem?
also what does 55MV stand for for the power rating? would a 55V work or no?

Perry Babin · 27th July 2008, 01:02 PM

Push down on the top. If it goes down and pops back up, the cap is probably OK. If you're still concerned, you can cut the plastic top off to see if the cap has vented.

Are you sure it's not WV (Working Voltage).

To find broken legs, you often have to push the transistors to the side. The legs sometimes break inside the body of the transistor.

audiobahnkid592 · 27th July 2008, 05:34 PM

peery i applied prussure to each leg of each transistor with a small screw drive they all were tight. The cap Is WV just read it really fast and with force the top of the cap does infact go down then come back up.

audiobahnkid592 · 27th July 2008, 09:59 PM

tested in different vehicle amp was fine must have been a wiring issue.

Jonny Hotnuts · 28th July 2008, 12:18 AM

I would say its insufficient current is dropping the PS voltage below operating limits.

I have seen this happen especially when the ground is not able to handle the loads.

I would make sure the ground cable is attached firmly to a structural member (seat bolts are not good enough).

Good luck

27th July 2008, 12:34 AM	#1
audiobahnkid592 diyAudio Member Join Date: Mar 2007	jbl bp600.1 issue when under full power and heavy bass the amp goes into protection for about 1 sec then comes back on and is fine for 15 up to 10 15 min before it will do it agian for another sec. any ideas?

27th July 2008, 02:31 AM	#2
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	Does it ever cut off when you hit a bump? Some amps have a problem with insufficient support for the boards and the legs on the transistors break at the body of the transistor. When this happens on the gate leg of the transistor, the vibration (from bass or from hitting bumps) can cause the gate leg to break its connection which will prevent the transistor from swithing off when it should. This can trigger the over-current protection circuit. I'm assuming that you've checked the voltage across the B+/ground terminals and it's remaining near or above 12v. __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

27th July 2008, 01:02 PM	#7
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	Push down on the top. If it goes down and pops back up, the cap is probably OK. If you're still concerned, you can cut the plastic top off to see if the cap has vented. Are you sure it's not WV (Working Voltage). To find broken legs, you often have to push the transistors to the side. The legs sometimes break inside the body of the transistor. __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

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27th July 2008, 02:35 AM	#3
audiobahnkid592 diyAudio Member Join Date: Mar 2007	It does it standing still in a parking lot so i dont think vibrations are causing it but will look at it and ive had other amps on the same power and ground wires with no issues but i will also check that

27th July 2008, 06:46 AM	#4
amc32 diyAudio Member Join Date: Mar 2008	Is the amp mounted on the enclosure?

27th July 2008, 12:43 PM	#5
audiobahnkid592 diyAudio Member Join Date: Mar 2007	a bit more back ground i just bought this amp and a jbl b80.4 for 130 for both of them locally through craigs list. now i tock the cover off the 600.1 and noticed the clamps to clamp the transistors to the heat sink were lose i tightened all of them and put it back to gether and it worked fine but that one problem i mentioned. Also it was mounted on the enclosure but was only on it for about 45 min. it was on a 1.25CF sealed box powering a audiobahn AW1200Q if that means anything.

27th July 2008, 12:54 PM	#6
audiobahnkid592 diyAudio Member Join Date: Mar 2007	No broken transistor legs but i found the top of one capcitor swelled could this be a porblem? also what does 55MV stand for for the power rating? would a 55V work or no?

27th July 2008, 05:34 PM	#8
audiobahnkid592 diyAudio Member Join Date: Mar 2007	peery i applied prussure to each leg of each transistor with a small screw drive they all were tight. The cap Is WV just read it really fast and with force the top of the cap does infact go down then come back up.

27th July 2008, 09:59 PM	#9
audiobahnkid592 diyAudio Member Join Date: Mar 2007	tested in different vehicle amp was fine must have been a wiring issue.

28th July 2008, 12:18 AM	#10
Jonny Hotnuts diyAudio Member Join Date: Dec 2007	I would say its insufficient current is dropping the PS voltage below operating limits. I have seen this happen especially when the ground is not able to handle the loads. I would make sure the ground cable is attached firmly to a structural member (seat bolts are not good enough). Good luck

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