supertech super jumbo 747 j Blows Fuse

label321

label321

Member (SA)
Jun 8, 2015
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Hi everybody,

I own a supertech super jumbo 747 j since yesterday

That blows a fuse for some reason.

I put a metal screw in the fuseholder and then it works normal.

Im dont know what the reason is i hope its something simple.

Hopefully someone can help me out here.


Regards.
 
Superduper

Superduper

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May 30, 2009
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www.AnalogAlley.com
An over-current condition has caused your fuse to blow. The fuse is there to protect your boombox, because it will blow before your boombox blows. If you replace it with a screw, then your boombox has no protection and continued over-current WILL blow it. There are so many possible ways for it to blow, that no one can offer you a solution, only guesses. Even the worlds greatest tech will not be able to help you sight unseen. I suggest you immediately remove the screw and replace it with a proper fuse. If it works ok with the new fuse, then perhaps it blew because someone operated it at too high a volume for too long, or maybe there is a loose wire inside that grounded. If it blows again, I suggest you bring it to a repair shop to evaluate.
 
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label321

label321

Member (SA)
Jun 8, 2015
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Yes if i replace the fuse it blows again.

I can take a look if i dont see it myyself i can place pixtures here.

If that aint it i bring it to an expert.

Thanks for the massage.
 
hopey

hopey

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Dec 28, 2014
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It's probably the transformer (insulation failure due to age) does it work on DC or batteries?
 
Eddy

Eddy

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May 20, 2009
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It can be a bad capacitor in the power supply. Bridging the fuse with a screw is a bad idea. The fuse is there to protect the electronics
 
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label321

label321

Member (SA)
Jun 8, 2015
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hopey said:
It's probably the transformer (insulation failure due to age) does it work on DC or batteries?
Click to expand...

I dont have 20 D Batteries.

I dont have a powersuply 15v

I think that it must be repaired by an expert.
 
Superduper

Superduper

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May 30, 2009
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Somewhere over the rainbow, USA
www.AnalogAlley.com
It's why I soooooo dislike giving dodgy advice to newbies that they, themselves already concluded need professional service, is to teach them to blow up their boomboxes. Not all power supplies share the same voltage or amp outputs or the same polarity configurations. Although most might be ok, do you know for certain that the one PS they find is center positive? Do you know for certain that the boombox they have is center positive? Because I've seen some where that is NOT the case. Do you know for certain that the voltage advertised is actually accurate? Because I've seen regulated ones where the output is spot on, and I've seen unregulated ones where the output is much higher than what is on the supply, presumably on those, power regulation is on the laptop itself.
See link below for a consumer power supply with negative center connector.

power supply adapter, on amazon
 
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label321

label321

Member (SA)
Jun 8, 2015
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I'm Not using it with the screw i did that to look if it still works.

Visual inspecction says nothing.

Im not an expert in electronica so i wil send it to an repair feller.
 
caution

caution

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Mar 25, 2014
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Boomboxery
When the fuse fails, it prevents the circuit from damage.
When you put the screw in there, even for one second, you allowed too much current. It's possible that you have damaged something.
Hopefully it's just a shorted capacitor, and it was the only thing taking the extra current.
 
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label321

label321

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Jun 8, 2015
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caution said:
When the fuse fails, it prevents the circuit from damage.
When you put the screw in there, even for one second, you allowed too much current. It's possible that you have damaged something.
Hopefully it's just a shorted capacitor, and it was the only thing taking the extra current.
Click to expand...
If i power it on it works fine.

So i dont know hopefully its a cap like you said.

I wil bring it to an expert soon.
 
Admux

Admux

New Member
Feb 25, 2021
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Do you have a spare fuse .... use "like for like"... see it it blows again ... just try it with the radio on , low volume .... see if it works for a while before you play a tape ... when you play the tape , turn the volume up slowly and see if it pops the fuse... if it does pop the fuse and you feel comfortable about looking in the back of the box , check for anything that is super hot ... usually around the chips or transistors.... hope it helps
 
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label321

label321

Member (SA)
Jun 8, 2015
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Admux said:
Do you have a spare fuse .... use "like for like"... see it it blows again ... just try it with the radio on , low volume .... see if it works for a while before you play a tape ... when you play the tape , turn the volume up slowly and see if it pops the fuse... if it does pop the fuse and you feel comfortable about looking in the back of the box , check for anything that is super hot ... usually around the chips or transistors.... hope it helps
Click to expand...

I put a spare fuse in and now it works fine.

If it works it works.

Only thing that dont work is the FM Stereo light.

May someone here knows how to fix that issue.

If it break again for some wierd reason i wil bring it to a repair service tech feller.

Thanks everyone for the tips messages.
 
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