No Sound & No Lights on LD 150

[mrtiv 0]

My Lowdown LD 150 powers on with a nice thump but there are no lights and none of the controls work. There is a light buzz from the speaker and plugging an Ipod into the 3.5mm jack produces sound (but still with no control from the front panel). The two input jacks on the front panel don't work at all. I've had a look inside, tested all the voltages I could with a digital multimeter and they checked out fine. I wasn't able to definitively check any capacitors but visually they looked ok. An internet search revealed at least two other people with exactly this problem but no solution. So..... any ideas?

[mrtiv 0]

After a bit of disassembly and investigation, I found that the PCB shield on the passive input jack was loose and behind it, a ferrite bead: L5 had blown. No idea how or why, or if replacing it will fix the problem.... but at least I'm a bit further down the road :)

 

[psarkissian 364]

Bass guitar with active 9-Volt powered pick-ups?

 

[mrtiv 0]

I have a Westone Thunder 1A, which is powered by 2 x 9-Volt batteries.... but I always used the active input with that bass.

[psarkissian 364]

Two 9-Volts might be too much. Would need to know more on how the circuit is implemented.

 

In the meantime, it should be checked out by a Line 6 authorized service center who knows the

product to check that. Looks like chassis ground issue.

 

https://line6.com/find/service_center/ 

 

Or Mark Wright Music in Northampton,... he used to be a repair tech at Line 6 Rugby when we had a location there.

 

[mrtiv 0]

Thanks for your help. It seems strange to me though that an active bass should be the reason, even if it were to be accidentally plugged into the passive input. After all, I've had that bass since 1982 and it's been plugged into many different bass amps of varying types over the decades with no problem.

[psarkissian 364]

Don't know if it's the reason, but an intermittent chassis ground wouldn't help.