Diagnosis tips for dead old combo

[mathlang]

I've got an old Laney RBG400 that's been lying around for a couple of years. Got it out a while back and it's completely dead. No power light, no hums or pops - nothing. I opened it up to have a look and can't see or smell anything blown. Replaced all the fuses and still nothing. I've tried checking for continuity with my multimeter and I get lots of positive beeps, but I don't know where to test.

My main thought is that the toroidal transformer has given up the ghost. Does anyone know how to test this? Is it unusual for one to die without showing any obvious external damage? Could inactivity cause it to fail?

If I were to replace it, how can I tell from the circuit diagram which one to replace it with? It says it needs a 6123, but I presume that's an old manufacturer part number, Would this one be suitable...http://uk.rs-online.com/web/p/toroidal-transformers/2575231/. Is there a cheaper way?

Any help other might have would be grategully received.

ta
Matt

[ahpook]

Can you find the 9115 PCB (first page of the diagrams) and check the voltages on P4 & P5 ?

This will mean being inside it when it's on, so unless you're confident being around mains and feel safe doing so, please leave it to an expert

[Rocker]

If it has an IEC connector for the mains cable, is the mains cable itself good. Try it on something else. There is a fuse in the 13 amp plugtop. This might read as a pathetic suggestion, apologies if it does, but sometimes the simplest tests are successful at getting something to work again.

[mathlang]

Thanks for the replies.

- I'm not getting any power when it's on, so I don't think I can check the voltages.
- Yes, I've tried different power cables, changed the plug fuses and changed the power socket fuse. I'm seeing power on the internal side of the socket.

[rmorris]

[quote name='mathlang' timestamp='1491382008' post='3272517']
Thanks for the replies.

- I'm not getting any power when it's on, so I don't think I can check the voltages.
- Yes, I've tried different power cables, changed the plug fuses and changed the power socket fuse. I'm seeing power on the internal side of the socket.
[/quote]

Can you also measure mains voltage on the transformer side of the power switch (when it's ON) ?