Dead speaker output on Alpha 10 Amp

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Just looking for a little advice on what to look for on my Arcam Alpha 10 Integrated Amplifier. I bought it second hand a few years back and after a short initial period did not have the space for a HiFi having moved house.

When I got the space again recently and connected it back up I found that the right channel of Speaker A connections was completely dead. Speaker B works on both channels. I opened the casing up hoping for a nice simple fuse to replace such as on my A60, but no such luck.

I am far from an expert, but I can use a soldering iron and a multimeter, as well as follow directions. Any hints would be fantastic.
Thanks for the pointer.

Looking at page 13 of the service manual I can see a relay fior each speaker terminal (labled RLY1A, RLY2A, RLY3A & RLY4A. Right output to speaker A is RLY1A so that would be a good point to start.

I can't see any other relays that would affect just that one output terminal, but the last time I used a circuit diagram was GCSE in Technology 15 years ago.

What do I do to check for normal behaviour in this? Would I test a connection with power off then power on and/or compare that with a working known working connection? Would I need to put signet through it too? Also, if the relay is locked open circuit what would the next step be?

There's two possibilities - the relay you identified, or a cracked solder joint on the speaker A terminal. Examine around where the terminal enters the PCB and see if theres any sign of cracks. If there is, reflow with a soldering iron.

To determine if the problem is the relay, try tapping it with an insulated probe (such as a wooden/plastic chopstick!) and see if this causes signal to appear on Speaker A. If it does, then the problem is the relay and it is simplest to replace it.
What can I do with an oscilloscope to check it? A friend of mine used to repair TV's so may have one (he is fairly old now and not in the business these days).

Thanks Jaycee. Will have a look at the joint again, but I did have a little look there when I could not see any obvious fuses. With the chopstick check, am I right in the following procedure:

1. Connect speakers to both A terminals
2. Connect a source to the amp
3. Power it all on with the lid off the amp
4. Play music at a low volume
5. Poke the relay whilst running to see if that makes the sound come out the other speaker

Does this pose a significant danger for the speakers? (i.e. a reason the relay may have locked open?)
Thats pretty much it yes. As Speaker B works OK, and it's connected to the same power amplifier circuit, i wouldnt be too concerned about damage to your speakers. If you really want to be sure, use some cheap test speakers - I have some cheap car speakers for this purpose
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