Laney GH50L that makes no sound.

ols

I am the proud owner of a 50 watt Laney GH head, but recently it has developed a rather annoying problem - It no longer makes any noise.

I have swapped out the HT fuse and checked all the valves - they all light up and do not show obvious visual signs of problems.

The amp will power up and show lights, but will not emit any sound. It does occasionally let out a quiet crackle when turning the knobs but that is about the extent of the sound it makes. I had a friend at PMT look at it and he doesn't know what the issue is.

I was wondering if anybody here has had a similiar problem and if they could help post the outcome or solution...

Lew

Well, that sucks. Did you buy it new or used? Either way you should get intouch with the seller and get them to pay for the repair?

ols

I bought it brand new from a guitar shop in Norwich and it is still under warranty with Laney, but the shop are refusing to send it back to laney as they want to investigate the amp themselves first (and presumably charge me for the privilege, although I have already had the amp examined by another guitar shop who couldn't diagnose the issue...)

ICBM

If the knobs make occasional crackling noises it suggests that the amp is working but that signal is not getting into it. The fault is most likely early on in the circuit, eg the input jack or the first valve stage. Finding it is a simple matter of conducting a 'disturbance test' back through the circuit until you find the point where no noise is produced.

Any tech who can't diagnose such a simple fault in about five minutes is not worth taking the amp to, frankly.

Lew

There's no way you should have to pay anything. Get 'em to send it back to Laney or get a refund. If they're being arses get intouch with Laney themselves. If all else fails send it to ICBM, seems to know what he's talking about ;-)

ols

Thanks for your input ICBM - Is there anything you would recommend me looking at in regard to such "disturbance tests"?

I'm not sure I could be entitled to a refund from the shop, as I have owned the amp now for over a year. I also have the contact details for Headstock distribution, so if all else fails I could approach them i guess.

ICBM

Sorry, I hope that didn't come over as dismissive.

First - if the amp is under warranty you should not pay for fixing it, unless you broke it.

Second, "no sound" or "amp completely dead" is actually the simplest type of fault to find, even though it sounds like the most serious. It's the ones where it makes odd noises, sounds bad, works but is too quiet, or worst of all something intermittent goes wrong with it, that are hard to find.

In almost all cases of no sound at all you can find where the fault is in a matter of minutes or less by simple logic or measurement. It's almost a certainty that it's a single valve, component or solder joint which has failed. Valve amps are not very complex things to diagnose, especially if you have the schematic. Even if you don't, they're usually simple enough.

ols

ICBM said:

Sorry, I hope that didn't come over as dismissive.

Not at all, it's helpful to have feedback from someone who knows that they are on about!

I will take it back to said store and argue the case with them. I will also make it very clear that I won't be paying for it's repair - although I will be happy to pay for a replacement valve if it just so happens that it's a valve that is the problem.

If they don't help - i guess i will be in touch with headstock.

Grumpyrocker

Definitely get in touch with Laney, they are a great company to deal with. And it's worth telling them their dealer isn't doing things right.

ThePrettyDamned

Laney have great customer service in my experience, so email them.  When my LH50 went super dead quiet on the dirty channel, followed by the clean channel dying, it was just valves that needed replacing - a power valve AND a preamp valve (a very unusual circumstance I believe!).  

ICBM has the gist of it though.  But I'd get into contact with Laney, they look after customers.  

ols

Thanks guys. Will do!