How much would you pay for a non-functioning tube head without knowing the issue?

[Adieu]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Hey Adieu, I just want to mention because I don't know your tinkering level -but you need to dissipate the filter Capacitors before messing around in there too much. You can die from stored energy in a 100W amp -long after it's powered down.

I'm sure theres a good video online with the TSL100 -my Marshall knowledge for where components are ends at JCM900s unless you post pics

FOUnd one
https://youtu.be/2iqmDf0QIyM

Sorry if you know all this already -but even though I don't know you, I do care.:haha:

Yeah i know enough to know to do it...but not enough to remember how it's done without googling lol

 

[NegativeEase]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Yeah i know enough to know to do it...but not enough to remember how it's done without googling lol

I got electrocuted onstage mid song in New York City 2 weeks ago -so It's a bit fresh on my mind!

 

[Adieu]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Looking forward to seeing how this goes. I want to get into amp tinkering.

Good luck!

I might even risk doing a youtube video and embarrassing myself in public lol

So far, just exposing the tubes and trying to boot her up, I got nada... 4 evenly glowing JJ 12ax7's and 4 evenly glowing TAD EL34B-STR Selected, nothing flickers, nothing dim, nothing red... all channel indicator LEDs light up when switched, but no input jack sound, no fx loop return sound

Though I guess that *IS* ~$150 in halfdecent glass already, then?

 

[NegativeEase]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

I might even risk doing a youtube video and embarrassing myself in public lol

So far, just exposing the tubes and trying to boot her up, I got nada... 4 evenly glowing JJ 12ax7's and 4 evenly glowing TAD EL34B-STR Selected, nothing flickers, nothing dim, nothing red... all channel indicator LEDs light up when switched, but no input jack sound, no fx loop return sound

Though I guess that *IS* ~$150 in halfdecent glass already, then?

Play into the Input and then listen to the FX send out by putting it into another amp -that way you can isolate the issue to Pre Amp stage or power stage.

 

[Adieu]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Play into the Input and then listen to the FX send out by putting it into another amp -that way you can isolate the issue to Pre Amp stage or power stage.

Do i need to have both amps attached to speaker loads, or just the other one?

 

[Adieu]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Silly question time: can I discharge caps with hugeazz automotive 6ohm 50watt resistors? Don't really have anything else on hand

 

[NegativeEase]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Do i need to have both amps attached to speaker loads, or just the other one?

well, do the test fast and you can just load the second amp so you can hear the test.

But don't do it (where the broken amp is unloaded) for more the long enough to establish if the preamp section works -which should take 10-20 seconds.

 

[NegativeEase]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Silly question time: can I discharge caps with hugeazz automotive 6ohm 50watt resistors? Don't really have anything else on hand

Scared to advise on this... lol . but it will work -hell no resistor will work -it may sound exciting though.

 

[Adieu]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Scared to advise on this... lol . but it will work -hell no resistor will work -it may sound exciting though.

Wait, wasn't a bigazz resistor soldered to a wire clipped to chassis and touched to v1 or something the PROPER way to discharge caps???

 

[Chistopher]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Definitely use a resistor. I'm saying this because I like you, but you don't seem to have a 100% grasp on what you are doing, so I'd suggest at least a couple of days of research before you go prodding around too deep into that thing. Death is a serious risk that must be considered when working on the circuitry of an amp. If you don't know what you're looking for or how to safely handle it, it's best to avoid doing so.

 

[Adieu]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Definitely use a resistor. I'm saying this because I like you, but you don't seem to have a 100% grasp on what you are doing, so I'd suggest at least a couple of days of research before you go prodding around too deep into that thing. Death is a serious risk that must be considered when working on the circuitry of an amp. If you don't know what you're looking for or how to safely handle it, it's best to avoid doing so.

Well my research keeps running into claims that the Marshall TSL design has self-bleeding resistors wired to the caps... but, then again, if an amp don't work, how do you tell if that part isn't affected as well??

 

[NegativeEase]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Well my research keeps running into claims that the Marshall TSL design has self-bleeding resistors wired to the caps... but, then again, if an amp don't work, how do you tell if that part isn't affected as well??

Indeed. You can't assume the amp's safety features are functional.

 

[Adieu]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Hmmm.... I found a (the?) culprit



Blown HT fuse... do I understand correctly that it MAY be just from somebody trying to run the amp without a speaker load or a mains power surge, and swapping the lil thing COULD resolve all problems?

Or does it mean that there's almost certainly something else wrong and the replacement will cook as well? Also, IF that is the case, am I risking further damage by just trying to replace the fuse first?

 

[NegativeEase]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Hmmm.... I found a (the?) culprit
View attachment 95361


Blown HT fuse... do I understand correctly that it MAY be just from somebody trying to run the amp without a speaker load or a mains power surge, and swapping the lil thing COULD resolve all problems?

Or does it mean that there's almost certainly something else wrong and the replacement will cook as well? Also, IF that is the case, am I risking further damage by just trying to replace the fuse first?

So all of your pre amp and the 4 power tubes were coming on and glowing red even though the HT fuse is cooked? How many fuses does a TSL have? one preamp and one HT fuse? wouldn't the power tubes be off if the HT went?

Also, HT fuse is easy to blow disappating a caps incorrectly -did you maybe blow this after you got home?

 

[Lake Placid Blues]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Make sure you replace the fuse with the proper value and type. Should be a slow blow. A Slow Blow fuse has a T subfix on the part number. A bad tube could have caused it. If so it will do it again. Get a few fuses. Tubes lighting up means nothing. That's just the heaters. On the other hand with a new fuse in there, if one the plates inside the tube start glowing cherry red-shut it down!

On another note you can drain the caps by running a jumper from one the preamp tube plates to the chassis. You don't need a big resistor or anything. It will drain slowly through the plate resistor.

 

[Adieu]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

So all of your pre amp and the 4 power tubes were coming on and glowing red even though the HT fuse is cooked? How many fuses does a TSL have? one preamp and one HT fuse? wouldn't the power tubes be off if the HT went?

Also, HT fuse is easy to blow disappating a caps incorrectly -did you maybe blow this after you got home?

Nope I only got around to getting the guard grate off and trying to heat the tubes via normal operation...then went to grab some dinner while reading up on possible issues and contemplating whether to trust Marshall's bleeder resistors

Then checked fuses, found a fried one, and went to the electronics store and picked up a baggie of replacements....as well as, don't worry, insulated 16 gauge alligators and a 200k ceramic resistor in a whopping 10w (Marshall forum suggested 2w, but that's all the shop could find 5 minutes before closing, and assured me it'd be ok) just in case

 

[Adieu]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Make sure you replace the fuse with the proper value and type. Should be a slow blow. A Slow Blow fuse has a T subfix on the part number. A bad tube could have caused it. If so it will do it again. Get a few fuses. Tubes lighting up means nothing. That's just the heaters. On the other hand with a new fuse in there, if one the plates inside the tube start glowing cherry red-shut it down!

On another note you can drain the caps by running a jumper from one the preamp tube plates to the chassis. You don't need a big resistor or anything. It will drain slowly through the plate resistor.

Yeah I got a baggie with like 5 fuses in the matching T1A 250v slow blow... if they cook again, gonna start by pulling power tube pairs, and if that doesn't do the trick, hitting the sockets with Deoxit

And only if that fails will I actually dig in and open her up.... although I've done it before on a TSL to switch it to Euro voltage (stupid switching is inside chassis, probably to idiot proof the thing?)

 

[Securb]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

You got this brother I think you are headed in the right direction.

 

[Adieu]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Well I'll be...

$0.80 FUSE SWAPPED & SO FAR SO GOOD

All channels work, sounds grrreat and hella raunchy through my ol g12-65/k85 Carvin 4x12 , even the volume is manageable from quiet to deafening... kinda makes me wonder if I shouldn't forgo flipping this for a quick $400-500 profit, and instead chuck my 2-day-old Mesa Boogie F100 back on craigslist

 

[Gtrjunior]

Re: How much would you pay for a non-functioning tube head without knowing the issue?

Well I'll be...

$0.80 FUSE SWAPPED & SO FAR SO GOOD

All channels work, sounds grrreat and hella raunchy through my ol g12-65/k85 Carvin 4x12 , even the volume is manageable from quiet to deafening... kinda makes me wonder if I shouldn't forgo flipping this for a quick $400-500 profit, and instead chuck my 2-day-old Mesa Boogie F100 back on craigslist

ATTA BOY!!!!