Arcam Alpha 7 CD.....DEAD....R.I.P.???

[tonewheelkev]

Hi Folks
.....went to my Alpha 7 CD player today....and now totally dead...no warnings, funny noises....just zip!

Had some help a couple of years ago with Mission Cyrus Amp....and found that the fix was a simple and cheap one...problem being with the 4 diodes in the power supply.

Is this worth checking...or should I be looking elsewhere...??
Grateful for any pointers...😉

 

[JonSnell Electronic]

Have a look in the service manual and check the power from mains to dc supplies..

 

[tonewheelkev]

Thanks
...Can find the handbook....but service manual not so easy!
Is there a good source for manuals online??

 

[Mooly]

Totally dead ? Check for any fuses that might be blown. Do a resistive check on the transformer primary (across L and N) of the mains plug. Check for any bulged caps in the PSU (I think Arcam is brand that suffers from cap issues from memory)

 

[tonewheelkev]

Thanks again!!
A Engineer pal...has just taken me through that resistance check over the phone....and based on that...reckons it's the primary on the transformer!!

The transformer is marked as Amethyst / AD2820 /L811TX (1) / 9608(date code??)

....so hoping I might find a suitable replacement.

Caps appear to be OK BTW!!!

 

[Mooly]

OK 🙂 but you need to check internally in case there is a separate fuse. Measure now directly across the primary of the transformer itself. If it really is open then its most likely got an inbuilt (and non replaceable) thermal fuse. The big question then is 'was it pushed or did it jump', in other words is there a short in the secondary side somewhere that has caused it to overheat.

 

[tonewheelkev]

Have checked the fuse on the PC board....OK

Is there possibly another fuse in the transformer casing?....need to take the PCB out to get at that from underneath!!

Incidentally...I noticed..,.a couple of weeks ago when you helped me by suggesting I clean the laser lense...that the transormer casing was quite warm...perhaps even hot!!

 

[Mooly]

The fuse in the transformer is not usually user replaceable. Do a google search for 'thermal fuse primary' or something along those lines and you should be able to find some information. They are a common failure item across the board but they are also a vital safety requirement. Transformers can fun quite hot so that doesn't automatically mean a problem.

 

[tonewheelkev]

Thanks again.....

Still can't find any refernce to the transformer:

Amethyst / AD2820 /L811TX (1) / 9608

...must I go to Amethyst....or are there alternatives?

 

[Mooly]

Without a doubt unique to that player. Might be worth trying Arcam themselves for spares, in fact that is probably the best route tbh. This is something you won't find an off the shelf item to replace with.

 

[tonewheelkev]

Got one!!

£21.00 vat....to include delivery...from Arcam.

Pleased with that.....Amethyst quoted £35.00 ish.....

Hope my diagnosis was correct....will report back.....😀

Thanks again!!

 

[Mooly]

Excellent. No doubt in the diagnosis if the tranny read open on its primary.

Be aware that if there is a fault in the player (such as a short) then the new tranny will quickly heat (not instant, perhaps a minute or two) and go the same way. So if the player doesn't work instantly then pull the plug straight away.

 

[tonewheelkev]

...Transformer arrived yesterday....easy fit...and now works perfectly!
(Well...seems perfect to me....somehow sounding better than before in a 'new transformer fitted' kind of way)

 

[Mooly]

That's great 🙂 Jobs a good 'un then !