I have two Spider IV (75 and 150) with the same signal path disruption

[spydox]

Oddly, both my Spider iv 75 and 150 have developed almost the exact same issue. 

 

Play the guitar , and the sound is attenuated like 99%, even with volume up, but sometimes pops up to full volume when changing settings like to BLUES for example.  Full volume resumes for a second or two , then goes back to like 1% volume.

 

The input jack seems ok- moving it about doesn't change things.

 

Seems like the signal path is disrupted- some plug or cold solder joint perhaps? Seems like a mechanical issue not a chip fault. I did perform a factory reset. No difference.

 

Advice on self-diagnosis/repair is appreciated. I have a VTM, mini color o-scope, and signal generator and more on my bench. 

 

Since two of my three Line 6 amps (the other is Spider V 240HC) have this issue , statistically, sounds like this is a probable fault that many many people have had.  I'm hoping that there are many methods to diagnose and fix it..

 

TY,

Eduardo

 

[psarkissian]

1-Double check your speaker cable. Make certain they are 8-Ohm speaker cable with 1/4" plugs and not guitar cables.

2-Make certain that the 8-Ohm speaker out is going to an 8-Ohm jack on the speaker or speaker cabinet.

 

Last time this issue showed up in our lab, it was one of those two reasons which are a result of impedance mis-match.

 

[spydox]

Ty for this reply. These are both COMBO amps with everything 100% original. So none of that applies. The Spider 240HC is a head, but its performing great. I was just mentioning that to indicate that 66% of my gear has this issue!

 

TY

[spydox]

On 9/9/2024 at 12:15 PM, psarkissian said:

1-Double check your speaker cable. Make certain they are 8-Ohm speaker cable with 1/4" plugs and not guitar cables.

2-Make certain that the 8-Ohm speaker out is going to an 8-Ohm jack on the speaker or speaker cabinet.

 

Last time this issue showed up in our lab, it was one of those two reasons which are a result of impedance mis-match.

 

PS Im not seeing service centers close to 32905.

 

 

[psarkissian]

Used to be a couple between Homestead and Jupiter. One might have retired, he was older than me.

hmmm,...

 

[spydox]

Jupiter isnt too too far but doesnt show up on the map?

 

[psarkissian]

Use Firefox or Chrome.

 

Also, if there's a problem with the headphone jack, like a short, it will put the output amp into "Mute" mode.

Rare, but it can happen.