5150 Problem - No sound, Tubes not glowing

[halford]

Hey guys

Last night other guitarist fired up his 5150 and there was no sound. On/off switch light working and stand by switch working. No sound, and no tubes lighting up.

Anyone got any ideas of what it could be?

He has blown the fuse before and said its acting different to when that happened last time.

Cheers
Halford

 

[halford]

Grid resistors?

Hey man, thanks for that.

what are grid risistors?

something he cant check?

Halford

 

[MrDan666]

I bet its a bad power tube..

I had exactly the same problem, exactly as your describing, when i recieved one of my Cameron Marshalls. Power light lit up etc, but none of the tubes lit up. I took out every tube, and put them in one at a time, turning on the power switch after adding each tube... And everything was back to normal and working, until i got to the bad tube. It caused all the tubes to stop lighting up.

Tell him to try that and see if one is causing the problem. Keep the amp on standby the whole time. Just power up after each tube.

 

[halford]

I bet its a bad power tube..

I had exactly the same problem, exactly as your describing, when i recieved one of my Cameron Marshalls. Power light lit up etc, but none of the tubes lit up. I took out every tube, and put them in one at a time, turning on the power switch after adding each tube... And everything was back to normal and working, until i got to the bad tube. It caused all the tubes to stop lighting up.

Tell him to try that and see if one is causing the problem. Keep the amp on standby the whole time. Just power up after each tube.

Hey man

Thanks for that. THis seems like it could be it.

I was wondering how they ALL were not working. But asd you said looks like it only takes one.

Will report back

Halford

 

[MrDan666]

Hey man

Thanks for that. THis seems like it could be it.

I was wondering how they ALL were not working. But asd you said looks like it only takes one.

Will report back

Halford

Cool man, hope that helps!

FWIW.. the bad tube, when i took it out of the amp, i could hear something rattling around inside the glass if i gently shook it. The others werent like that. That could be an indicator!

 

[Rampage]

Have you tried cleaning the effects loop jacks? My old 5150 went silent on me once, and spraying some deoxit into the jacks brought it back to life.

 

[halford]

Have you tried cleaning the effects loop jacks? My old 5150 went silent on me once, and spraying some deoxit into the jacks brought it back to life.

Hey,

yeah i know this is a common problem, but for no tubes to light up did not indicate the effects loop to me.

Will get him to look at all these things.

Cool man, hope that helps!

FWIW.. the bad tube, when i took it out of the amp, i could hear something rattling around inside the glass if i gently shook it. The others werent like that. That could be an indicator!

Is having one power tube in and turning it on bad for the amp?

Thought it would be.

Im sure you have a answer to that

Halford

 

[MrDan666]

Is having one power tube in and turning it on bad for the amp?

Thought it would be.

Im sure you have a answer to that

Halford

No its not a problem at all, just make sure the amp is on standby (not in playing mode). That way you aren't putting any HT voltages to the tubes. The tubes will be just receiving heater voltage.

 

[JerryP]

http://www.fjamods.com/phpBB3/viewtopic.php?f=11&t=2 Read my amp powers up but no sound
Jerry

 

[halford]

Have you tried cleaning the effects loop jacks? My old 5150 went silent on me once, and spraying some deoxit into the jacks brought it back to life.

Hey man

not on this one yet, happened last night, and he just grabbed another amp.

I have forwarded all these suggestions onto him.

We will see tomorow most likey!


JerryP - thansk for the link, GREAT faq page

MrDan66 - cheers for that!

Halford