NAD 7175PE blown fuse help

[chewy61]

Hello, I have a Old NAD 7175 PE that blew the 250V MDL 3/8 buss fuse & stopped working. I replaced the fuse with a 3/8a slow blow fuse and it still wont work. 1) Does it have to be an MDL 3/8a fuse? 2) What else might be the problem? I don't want to take it in if I could fix it.

 

[TLS Guy]

Hello, I have a Old NAD 7175 PE that blew the 250V MDL 3/8 buss fuse & stopped working. I replaced the fuse with a 3/8a slow blow fuse and it still wont work. 1) Does it have to be an MDL 3/8a fuse? 2) What else might be the problem? I don't want to take it in if I could fix it.

What is the current rating of the fuse? Do not use a slow blow. Replace with a fuse of the same amp rating.

Replace the fuse once. If a fuse of the same amp rating blows then the unit has a serious problem. Most likely deep trouble in the power supply or a blown output stage in one of the amps. The unit will not be worth fixing. I would recycle.

 

[M Code]

What is the current rating of the fuse? Do not use a slow blow. Replace with a fuse of the same amp rating.

Replace the fuse once. If a fuse of the same amp rating blows then the unit has a serious problem. Most likely deep trouble in the power supply or a blown output stage in one of the amps. The unit will not be worth fixing. I would recycle.

An MDL fuse is a slo-blo type...
The slo-blo is used as it will take 100% current overload for a longer time than a fast blo. (AGC) If the factory calls out for slo-blo continue to use a slo-blo..

Just my $0.00..

 

[TLS Guy]

An MDL fuse is a slo-blo type...
The slo-blo is used as it will take 100% current overload for a longer time than a fast blo. (AGC) If the factory calls out for slo-blo continue to use a slo-blo..

Just my $0.00..

Well spotted, I did not notice the slow blow. But if it blew a slow blow fuse that is bad news, and the amp is likely history.

 

[chewy61]

Well spotted, I did not notice the slow blow. But if it blew a slow blow fuse that is bad news, and the amp is likely history.

Hello, thanks for the reply. The notation on the fuse says "3AG 3/8A 313" The container says "Slo-Blo". The amp won't light up or work let alone blow another fuse. I'll go out and get a non sloblow and try that next.

 

[TLS Guy]

Hello, thanks for the reply. The notation on the fuse says "3AG 3/8A 313" The container says "Slo-Blo". The amp won't light up or work let alone blow another fuse. I'll go out and get a non sloblow and try that next.

Do not replace fuses any more. That is dangerous. That unit is done and needs to be recycled.

 

[miniSQ]

is there a reset button someplace?

 

[PENG]

Hello, thanks for the reply. The notation on the fuse says "3AG 3/8A 313" The container says "Slo-Blo". The amp won't light up or work let alone blow another fuse. I'll go out and get a non sloblow and try that next.

The 3/8A 313 is a slo-blo 3/8=0.375A fuse. Did the replacement one you put in blow? If not then something else need fixed. If it did blow again then getting a non slo-blo would not help as it would blow even quicker right?

A 250V 0.375A fuse is not going to be the one for the main power supply but for something much smaller so the power supply may still be okay. Without a circuit diagram to look at it will be tough to come up with any idea. Are there other fuses in the unit that you has not been checked? On the other hand unless you are a qualified electrician or electronic technician you really should not play around with 250V. I suggest you get a qualified person (may be you are but I don't know that for sure) to take a look of the unit for you before you recycle it.

 

[TLS Guy]

Have you always owned this unit.

I have downloaded the service manual circuit and parts list from HiFi engine.

There is only one fuse in that unit and it is the AC line fuse.

This is what is specified: -

FU951 It is a 5 amp fuse for 125 volt operation and a 2 amp fuse for 250 volt operation, in the UK. It does not specify a slow blow fuse.

The units sell for about $175 on eBay.

Replace the fuse once with the correct fuse for your house voltage in your country, once.

If the unit fails to operate or blows the fuse right away, It will need service or recycling.

I would imagine that the unit will likely exceed its value in the repair bill. To even have it looked at will incur a charge, and I would think putting the money to something else would be more worthwhile.

 

[PENG]

If the OEM fuse is supposed to be a 2A fuse, the 3/8=0.375A fuse will blow almost every time as soon as he turned it on.