Arcam fmj a22 it go bang

[errol8000]

Hi I bought this amp as not working checking inside I could see the fuse had burned out 2.5 amp AS 250v. I did not have an equivalent so i replaced it with a 1.6a AS slow blow thinking if there was nothing wrong it would just power on. (Idiot) pressed the power on and watched the display light up nicely for a few seconds before the relay clicked in then BOOM c109 went of like a fire cracker.
The service manual I have for this is what arcam sent me for the alpha 10 stating it was the same.
Can you please tell me if the fuse on this is a quick blow and not slow?
Also is this cap that blow a psu filter cap? And where on farnell can I get it I had a look but nothing reads the same, thanks.
Also I measured the main mosfetts and they all read between 150 and 600 on continuity.

[singa]

Hi, If you use 1.6A fuse instead of the original 2.5A of course it will blow because it is less than required.From practical standpoint if the original fuse is a slowblow you can use a fast blow type whether it will last is another question.You can use a higher rating like 3A fast blow.Slow blow fuse markings are different from slow blow but physically there either have a few turns in their fuse structure or a blob of solder on a straight fuse material.

You can find a replacement cap most likely a suppression type for the power
input side from farnell Capacitors | Farnell United Kingdom

Choose passive components and then film (capacitors) then select the value
and the search will give you alternatives.

Do not rush to replace fuse as some other component is short,check thoroughly before turning on again.

[errol8000]

Actually the fuse was still intact and fully funtional it was the cap that went.

[jaycee]

It looks like a line filter (x2 rated) capacitor. It was probably due to fail, possibly damaged by a line surge.

[errol8000]

Thanks for your answer jaycee i spoke to arcam and they did not have it listed on there service book so they had to open a unit they had there and ask me to direct them to it quite funny really. Do you think i might get lucky if i pop the new one in and the right fuse it might fire up this time just not literally lol.

[Tekko]

LOL What a bunch of noobs!! Well if THEY had to ask YOU for directions.

Now i wont ever trust a product with the Arcam logo on it, will be torn apart and rebuilt.

[errol8000]

I don't think it was quite so simple as that the diagram they have is for the alpha 10 only they have updated a few components internally when it became the a22 c109 was one of them which was not on the schematic i am sure they just wanted to send me the right part. The amp is about 12 years old.

[jaycee]

At least Arcam offered to help and were willing to take apart a unit themselves - if this was any other company they probably would've told you it's "no longer serviceable" and to buy a new one !

It's hard to say if dropping in a new capacitor will fix this - it depends what caused the fuse to blow in the first place. At a guess, it is just an interference suppression capacitor and the unit would run with it removed - but without seeing either a schematic, or the unit for myself, i would be uncomfortable with suggesting this.

[errol8000]

Originally Posted by jaycee

At least Arcam offered to help and were willing to take apart a unit themselves - if this was any other company they probably would've told you it's "no longer serviceable" and to buy a new one !

It's hard to say if dropping in a new capacitor will fix this - it depends what caused the fuse to blow in the first place. At a guess, it is just an interference suppression capacitor and the unit would run with it removed - but without seeing either a schematic, or the unit for myself, i would be uncomfortable with suggesting this.

Your right the fuse i replaced it with 1.6amp AS slow blow instead of the original 2.5amp did not blow, it might have been still on but i reached for the off button so fast i did not notice.
As to Arcam service you can't knock it really they are even trying to find out if some buttons i have missing on the front can be replaced from a diffrent later unit.

[h_a]

Do you think i might get lucky if i pop the new one in and the right fuse it might fire up this time

You must be kidding?

I didn't work the first time, so why should it work now?

The unit needs serious repair and I can only warn you to try to repair it yourself. The damage will likely only become bigger and further you risc getting hurt.

Hannes