# JL Audio 500/1 with a blown transistor, were to buy parts?



## CRD

I recently got this amp and found out that its not working. The green light turns on and secodns later the thermal light flashes once and the subwoofer bumps, after that the green light stays one but doesnt sound.

I opened the amp and saw a blown resistor labeled Q510 , see pictures.

I cant see the numbers on the transistor because is melted, I was just wondering were can I buy this transistor? or if any of you can take a look on your 500/1 and tell me the part number.

Any help will be apreciated


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## Volenti

That's not a high power transistor and there shouldn't have been enough current in it's circuit to make it explode like that, I'd put money on it being a symptom of a bigger fault, possibly shorted output devices.

Time to see how deep the rabbit hole goes...


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## CRD

Volenti said:


> That's not a high power transistor and there shouldn't have been enough current in it's circuit to make it explode like that, I'd put money on it being a symptom of a bigger fault, possibly shorted output devices.
> 
> Time to see how deep the rabbit hole goes...


The only damaged parts I found were those 2 transistors, they are both blown with a hole on them.

I cant see any other damage at least visually damage.


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## Volenti

The output transistors can fail to a short condition with no outward signs of damage, roughly half of the amps I see with blown up powersupply stages have shorted output devices, sometimes the output devices explode, sometimes the powersupply fets explode, but something usually explodes.

There is a reason those transistors exploded, it is unlikely to be suicide, you need to look for the murderer. You can check the output transistors in circuit for a short condition with a normal multimeter, or on diode setting.


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## JAX

Volenti said:


> The output transistors can fail to a short condition with no outward signs of damage, roughly half of the amps I see with blown up powersupply stages have shorted output devices, sometimes the output devices explode, sometimes the powersupply fets explode, but something usually explodes.
> 
> There is a reason those transistors exploded, it is unlikely to be suicide, you need to look for the murderer. You can check the output transistors in circuit for a short condition with a normal multimeter, or on diode setting.



ha ha ..murderer....the dude that sold it to him....ha ha


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## envisionelec

CRD said:


> I recently got this amp and found out that its not working. The green light turns on and secodns later the thermal light flashes once and the subwoofer bumps, after that the green light stays one but doesnt sound.
> 
> I opened the amp and saw a blown resistor labeled Q510 , see pictures.
> 
> I cant see the numbers on the transistor because is melted, I was just wondering were can I buy this transistor? or if any of you can take a look on your 500/1 and tell me the part number.
> 
> Any help will be apreciated


I don't own a 500/1, but those are totem drivers for the power supply transistor. They are pretty generic PNP/NPN pairs. You can actually look at the other three similar-looking transistors. Two will have the same part number - and the other one is the part number of your blown one.

But, the kicker is that you have about $50 in damage to the amplifier in parts alone. The power supply transistors. The UC3843 driver IC, and those totem driver transistors, at minimum. Then, you have to see if something else is wrong once you get the power supply working.


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## Alex Tham

I also have blown my JL 500/1. But it seems like blown the transformer as picture. Any expert here can consult me what is caused it blown the transformer? All the transistor are in good condition (no blown sign and clean). Kindly please advise what type of transformer I should buy to replace it and where to get it. Thank you very much!!!!


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