Thank you
The backs are exposed metal.
I will get 2 more to replace the outer ones.
Thanks, I removed both drivers and confirmed they conduct in 1 leg and out the other 2 legs with no reverse current leakage. My multimeter read .695 on the diode-check setting. I also checked the diode that is across the drivers, it read .550 in only 1 direction, when removed from the circuit.
I removed (zener?) diode at ZX1 (pic at post 19). It read .550 in 1 direction only, and actually looks ok. That was my biggest concern it that area, and as Perry stated before, it just looks like that area got hot.
I just noticed the speaker terminal connections. It has 2 screws in and the other 2 half out. The 2 that are half out are the left+ and the right+.
Would it be presumptive of me to suggest that someone has bridged a speaker across these 2 terminals?
Is this a likely scenario considering the damage to this amp?
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In most 2-channel amps, you will have one positive speaker terminal and one negative speaker terminal used for bridging. The two NOT used for bridging will read 0 ohms between them.
If they didn't use the two bridging speaker terminals, the amp was only driving the speakers from one channel. This should not have caused any damage to the amp since the acceptable bridged load has twice the impedance of the acceptable load impedance for either of the individual channels.
If they didn't use the two bridging speaker terminals, the amp was only driving the speakers from one channel. This should not have caused any damage to the amp since the acceptable bridged load has twice the impedance of the acceptable load impedance for either of the individual channels.
So this amp should go when i put the new FETs in and change the other 2 output transistors?
Are we happy that most of the checking is complete?
Are we happy that most of the checking is complete?
There's a good chance that it will be OK when you power it up but it may not. Before applying power, clamp all transistors tightly to the heatsink and power it up through a single 10 or 15 amp fuse. If the fuse doesn't blow, test it at low volume for at least a few minutes. If nothing gets hot (except the large resistors for the regulators) and the fuse doesn't blow, it's likely OK.
Thanks, I will have to wait until the parts arrive, then I will get back with results.
I have to work away as well, so it will be a couple of weeks before i can try the amp.
Thanks for your help, and looking at other posts and pics on here, I am suprised at the visual simplicity of my board, compared to some of the others.
Certainly, I am envious of the knowledge shown here.
I have to work away as well, so it will be a couple of weeks before i can try the amp.
Thanks for your help, and looking at other posts and pics on here, I am suprised at the visual simplicity of my board, compared to some of the others.
Certainly, I am envious of the knowledge shown here.
Just an update, the power supply FETs arrived, so i have installed them. checked for short at the B+ to NEG and had to fix a small bridge of solder.
Powered up with a 10A fuse and all good, ran quietly for 5 mins on each channel and then bridged. All good so far.
R401 and the same on the opposite channel get quite hot to touch. (attached in the quoted post above or at post #19) Any comments on this? or are these the 'large resistors for the regulators'?
I replaced the 60A of fuses and wound it up then and it blew the 30A fuse in the main line near the battery. Replaced that with a 60A as that was as big as i have, and let it rip. Sounds good, i like it!
I am not using it yet as i am still waiting for the TIP35 and 36s to arrive, but it looks like it is fixed.
Much appreciated guys, and i have learnt heaps.
Looking at a blown Eclipse XA4000 as next project to replace my Pioneer 300w in the ute.....
The large resistors are often for the ±v regulators. They get hot but they the regulator resistors should be approximately the same temperature. Check the Zener diodes that they're connected to to see if they both have the same voltage.
I will get the correct matching TIP35s and 36s in (when they arrive) and have a look then. Maybe the channels are fighting each other a bit?
The regulator-resistors aren't associated with either channel. They produce voltage used by both channels.
Hi all, i have replaced the output transistors with a matching sets of TIP35 and TIP36.
Now this amp was testing ok before with the odd outputs, so i plugged it in and it fired up for around 30 secs with only a 10amp fuse for testing. It then blew the fuse, i replaced it and it blew even without the volume up at all.
I unplugged it and 2 of the new outputs were blown, i replaced them with 2 I removed earlier, reconnected and it blew the fuse again.
The amp will accept the power leads fine, and it blows the fuse about 3 secs after the amp turns on. The power transisters are ok, and the output transisters are fine as well,
Where should i be looking
Now this amp was testing ok before with the odd outputs, so i plugged it in and it fired up for around 30 secs with only a 10amp fuse for testing. It then blew the fuse, i replaced it and it blew even without the volume up at all.
I unplugged it and 2 of the new outputs were blown, i replaced them with 2 I removed earlier, reconnected and it blew the fuse again.
The amp will accept the power leads fine, and it blows the fuse about 3 secs after the amp turns on. The power transisters are ok, and the output transisters are fine as well,
Where should i be looking
Yes, the difference is that the new ones have a 220 insulated case, still with the exposed rear. i have maintained the insulation behind the TIP35/36 and only test clamped.
I will try replacing the TIP35/36 back to the mismatched set and test, as these tested ok before.
I replaced the TIPs and its going ok. The amp has promptly blown my sub once i got the fuses in and wound it up. Now the sub rattles. I will replace it and try again.
Hi again,
This amp has been unstable on the repaired channel. I am certain this is because it has mismatched output Tip's.
I found that the Tip's that I tried first had faults. I am waiting for the car to come back from panel shop and i will have another go at it with fresh matched Tip's
On another note, I have set up a bit of a bench to repair and test amps on, and have successfully repaired some simple amps, consisting of:
Boss 1000w, BA1000,
Yokohama1200w Yok-480,
Kicker 200.1,
Power Acoustic PA400.
I have purchased Perry's disc and studied it pretty well, and it is excellent providing learning that i would have trouble finding elsewhere. The repaired amps are a collection of broken ebay lots and friends broken amps, that i have volunteered to try to fix for fun.
I also have a Eclipse digital Xa-4000 with 1 'clicking' channel that is still a bit beyond me, but i have a thread on here, and i will add some scope captures and ask for thoughts and help there, at least it has 3 working channels, so i have to just compare the bits to make it go
This amp has been unstable on the repaired channel. I am certain this is because it has mismatched output Tip's.
I found that the Tip's that I tried first had faults. I am waiting for the car to come back from panel shop and i will have another go at it with fresh matched Tip's
On another note, I have set up a bit of a bench to repair and test amps on, and have successfully repaired some simple amps, consisting of:
Boss 1000w, BA1000,
Yokohama1200w Yok-480,
Kicker 200.1,
Power Acoustic PA400.
I have purchased Perry's disc and studied it pretty well, and it is excellent providing learning that i would have trouble finding elsewhere. The repaired amps are a collection of broken ebay lots and friends broken amps, that i have volunteered to try to fix for fun.
I also have a Eclipse digital Xa-4000 with 1 'clicking' channel that is still a bit beyond me, but i have a thread on here, and i will add some scope captures and ask for thoughts and help there, at least it has 3 working channels, so i have to just compare the bits to make it go
Hi i have a boss BA-1000 and i've blown the IRF44N transistors... i cant seem to find parts, do you know of a substitute for the 44n? and would you know why they would have blown?
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