Rotel RA-930AX P/S
 

My trusty Rotel amp has stopped working - a blown mains transformer
is suspected. There's no voltage on the transformer output.

I know its a long shot, but would anyone know the output
voltages or know where I could get a replacement transformer -
other than by taking it to a dealer?

Cheers,
Nick

"UK Nil Point, No Points.
Terry: time to send in a gunboat".

Rotel RA-930AX P/S
 

SixPack wrote:

My trusty Rotel amp has stopped working - a blown mains transformer
is suspected. There's no voltage on the transformer output.

I know its a long shot, but would anyone know the output
voltages or know where I could get a replacement transformer -
other than by taking it to a dealer?

Transformers are generally pretty reliable.
Is there any voltage on its input?
Does it have dual input windings for 120/240v?
If so, is the voltage selector switch working?
What are the resistances of the windings?
They should give an indication of whether it is working.

You could make a guess at the transformer spec from
the amp's power output and the voltage rating of the capacitors.

It would probably be cheaper to buy the RA930AX that's on ebay
at the moment than to buy a new transformer.


--
Roger.

Rotel RA-930AX P/S
 

"SixPack" wrote in message
...
My trusty Rotel amp has stopped working - a blown mains transformer
is suspected. There's no voltage on the transformer output.

I know its a long shot, but would anyone know the output
voltages or know where I could get a replacement transformer -
other than by taking it to a dealer?

Cheers,
Nick

"UK Nil Point, No Points.
Terry: time to send in a gunboat".


Unlikely to be a blown transformer - Rotel are well noted for the current
output of their amps so it follows that the transformer must be pretty
substantial as well.

No volts out, but has it got any volts in? Daft question but pertinent. If
there's no volts out, is that with it disconnected - i.e. is there a short
on its output (which like a faulty transformer would also likely blow the
mains fuse?) Is there continuity in primary and secondary when disconnected?

If it really is the transformer you would be best to try Rotel for a spare -
you will find difficulty getting one to do the job in the first place, and
even if you could would it physically fit?

IMSMC Rotel used to be handled by Gamepath in Milton Keynes.


--

Woody

Rotel RA-930AX P/S
 

Thanks for the ideas & suggestions. The transformer was getting
mains input OK, but I may do some more tests on the transformer
as suggested.

It just seems a pity do dump it but, as suggested, probably more cost
effective to get another 2nd hand one.

Cheers,
Nick

Woody wrote:
"SixPack" wrote in message
...

My trusty Rotel amp has stopped working - a blown mains transformer
is suspected. There's no voltage on the transformer output.

I know its a long shot, but would anyone know the output
voltages or know where I could get a replacement transformer -
other than by taking it to a dealer?

Cheers,
Nick

"UK Nil Point, No Points.
Terry: time to send in a gunboat".



Unlikely to be a blown transformer - Rotel are well noted for the current
output of their amps so it follows that the transformer must be pretty
substantial as well.

No volts out, but has it got any volts in? Daft question but pertinent. If
there's no volts out, is that with it disconnected - i.e. is there a short
on its output (which like a faulty transformer would also likely blow the
mains fuse?) Is there continuity in primary and secondary when disconnected?

If it really is the transformer you would be best to try Rotel for a spare -
you will find difficulty getting one to do the job in the first place, and
even if you could would it physically fit?

IMSMC Rotel used to be handled by Gamepath in Milton Keynes.

Rotel RA-930AX P/S
 

"SixPack" wrote in message
...
Thanks for the ideas & suggestions. The transformer was getting
mains input OK, but I may do some more tests on the transformer
as suggested.

It just seems a pity do dump it but, as suggested, probably more cost
effective to get another 2nd hand one.

Disconnect from mains & check the resistance of the primary winding -
measure between phase & neutral pins on the mains plug and have the amp
on/off switch turned on. Is there a fuse in your mains plug? Have you
checked?
You should get a reading of around 8 to 10 ohms. If it measures open
circuit, check for continuity in the cable and right up to where the
connections are made to the trasnformer, then check for a thermal fuse in
the primary winding. A lot of Jap amps do have such a fuse - problem is
though some are embedded within the windings and would be very difficult to
get at. However, you could get lucky and find it strapped to the exterior of
the transformer. A bit of careful diagnostic work should highlight where the
break is - all it'll cost you is a bit of time. Is there a fuse in your
mains plug? Have you checked?