Our amplifier was on yesterday and suddenly stopped working, the T1A fuse on
the 240V side of the transformer had blown, for no apparent reason. I did an
250V insulation test on the 240V side of the t/f and it was clear, there
didn't appear to be a short circuit on the 240V side of the t/f or an
interwinding fault or a fault to earth on the LV side, the connector from
the LV side is connected to a rectifier board with, I presume, some current
limiting feature. As far as I could see there was no obvious fault component
in the amplifier.

I didn't have any T (antisurge) fuses so I used a F1A quick blow fuse. The
amplifier worked fine last night but today the fuse blew within a few
seconds (or less) or the amplifier being switched on (using the button on
the front which switches the 240V circuit).

The amplifier is a Marantz about 12 years old.

Is it possible that using a quickblow rather than an anti surge fuse has
caused the fuse to blow the second time. Is there likely to be some current
limiting device on the rectifier board? Any other pointers things or things
I should look for.

Thanks

Ian