Blown Up Laney amps

[crumpet_tramp]

Hi all,

at a band practise recently and my laney combo (HCM65) recently doesn't work, First it does not power on but you can it hum. Too confuse the issue, if you use the fx return you can use the power amp and noise comes out the speaker. I have checked the fuse and it hasn't blown. I opened it up and i could find no other fuses to go wrong.

Then about two days later, i was using the head (RB700) and then this also just faded, this does not work if use the FX return. This time when i checked the fuses the main one on the back of the amp had gone. So i replaced this with a slightly smaller fuse and this blew up big time, and blew up all the smaller fuses inside.


Please let me know if im not being very specific or too vague
Please help, as i do not have any money to buy any more amps!

Is anyone able to help or know someone who is able to help me? I am prepared to travel, and live in Hampshire.

[Dread Bass]

where do you practice? was it the same place both times? something is def going on here

[crumpet_tramp]

No, they were in different places. The only comon feature were, bass used and lead used. Everything else was different.
Tnak you very much for your assistance

[thepurpleblob]

I think you've probably been unlucky. They weren't sitting in the back of a freezing cold van or outbuilding where they? I've seen condensation see things off if you don't leave them for a while to warm up.

You're going to have to take them to a tech to get fixed. It's unlikely to be something simple. A quick google turned up [url="http://www.stevesamps.co.uk/"]http://www.stevesamps.co.uk/[/url] - I don't know anything about them but it looks likely.

[tauzero]

[quote name='crumpet_tramp' post='330683' date='Nov 17 2008, 02:20 PM']at a band practise recently and my laney combo (HCM65) recently doesn't work, First it does not power on but you can it hum. Too confuse the issue, if you use the fx return you can use the power amp and noise comes out the speaker. I have checked the fuse and it hasn't blown. I opened it up and i could find no other fuses to go wrong.[/quote]

I suspect the power supply feed to the preamp section. The mains power will go to the transformer, and the transformer output voltage will be rectified and smoothed either on a separate power supply board or on the power amp board. From there, there will be a power take-off that will go to the pre-amp and the indicator light on the front (which I assume isn't lighting up when you say that it doesn't power on). That's come adrift or broken, or a PCB track has cracked at one end or the other. Consequence is that the power amp section (which includes the fx return) is up and running, but the preamp and power indicator aren't.

[quote name='crumpet_tramp' post='330683' date='Nov 17 2008, 02:20 PM']Then about two days later, i was using the head (RB700) and then this also just faded, this does not work if use the FX return. This time when i checked the fuses the main one on the back of the amp had gone. So i replaced this with a slightly smaller fuse and this blew up big time, and blew up all the smaller fuses inside.[/quote]

That sounds like it's trying to tell you something, like an output transistor blown.

[Musky]

Regarding the combo only working on the fx return, but everything else appearing to be ok (if I read that all right), I had this on a laney once. I took it into a tech, but it turned out to be dirt/corrosion on the input jack - it just needed a clean. It had been working fine up until then (and still does) but it was a bit baffling how it just packed in half way through a rehearsal.