wizard_37

I wrote about a problem with my 410H and no one can give me any advice this sucks

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gunboatstudio

Do you mean this thread here?

What is the best multi effects pedal to run with a marshall 410h head

It looks like you got a few suggestions there. I mean, "What's the best pedal?" is sort of subjective. Have you tried any out yet? What do you want out of your multi-effects pedal?

JohnH

Do you mean this thread?
jvm410H problem please help

You wont get answers without more info - forum members not being psychic.

What else have you done to figure out the problem? Tried a different guitar?, different cable? is the power light still on? do the tubes still glow? is the speaker still properly plugged in? etc

Lots of people here like to help others if they can, but need more to work with.

John

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DSL401
8412 cab
Crate Powerblock
1 x 12 Vintage 30 cab
'76 Shergold Masquerader
'93 Les Paul Studio
'83 Roadstar

madryan

First detail the troubleshooting routine you went through. The 410H is a head correct? If that's the case do you have pets or kids? Did one of them unplug the speaker cab? Do all your cables work including your speaker cable and do you have spares so you can check them? Is it a Marshall cab? Did that crappy little switching PCB in the cab blow?

Once you've ruled out everything outside of the amp and you're sure it's the amp then I'm sure folks can help. The problem is I don't own one and have no idea what kind of redundant fusing Marshall used in the JVM. I had Peavey's with multiple fuses so that even if the main fuse blew the amp would still power up and you'd have to pull the chassis to start checking fuses. Now you're talking about dangerous stuff.

So what's your status?

wizard_37

Guys i am so sorry i appolagize i have had a hell of a week, but it is nothing that simple, i double checked everything on the head, all the lights are coming on and the tubes aren't showing any signs of glowing, i am guessing it is the tubes, but then i don't see the preamp tubes glowing either, i have checked the fuses by the main power cord plug in and those are fine, i don't know if there are internal fuses or not and i did not want to open it up incase it would void the warranty, i did bring it in and they are checking it out and i will let you guys know what they find. Again i am really sorry i did not mean to affend anyone, i just took my fustrations out on this keyboard without thinking, i read this forum all the time and i know there alot of good people on here and i hope yall can forgive me for being a dick, it won't happen again.

JohnH

No problem - and good luck.

__________________
DSL401
8412 cab
Crate Powerblock
1 x 12 Vintage 30 cab
'76 Shergold Masquerader
'93 Les Paul Studio
'83 Roadstar

ToddOwnz

Did you get her fixed?

wizard_37

Found out its not the tubes, they are sending it off and the warrant will probably cover it so i will let you guys know as soon as they let me know what the problem is.

JimmyPage

I am having the same problem! Everything functional (foot-switch, selection buttons, lights) but no sound and no more warm glow. This was accompanied by an electrical smell briefly before the sound went out. I've had this amp three years now, is warranty going to cover this?
Does anyone know the cause?
If warranty won't cover it I'm not afraid to open it up, I've fixed many a marshall that just had weak soldering break away. I'm not gonna turn a screw on just a guess though, some insight would be awesome. I have no clue about the warranty info, guitar center sold me the damn display model (at no discount) and forgot the manual.

JimmyPage

OK, I'm not gonna be too much of a dirt-bag about it, but seriously, too many people post problems and never come back with real solutions.
... so...
I got tired of waiting and searching and dreading going back to guitar center to deal with more fools and waiting for my amp to be haphazardly thrown around in shipping.

If you have this problem, here is what the deal was for *ME*... *YOUR* situation is your own risk:

-Unplugged head/flipped upside down, removed 4 black screws. Carefully removed the naked amp.
-Was met with a terrible burnt smell. After searching pinpointed to one of the 10A 120V Slow-Blow fuses.
-Fuse had an apparent loose connection to one of the receiving terminals; The resistance caused some serious heat that still did not trip the SB Fuse. Luckily the solder inside the cap of the fuse melted away breaking the circuit before a fire happened.
-Soldered in a much more hefty replacement wire to beef up the circuit trace that was put through hell (just soldered point to point on backside of board, the tracer runs to one of the main transformer lead wires right next to the corresponding fuse.
-Thoroughly cleaned all contact area where the fuse will contact the metal terminal especially where it originally made the faulty connection and crimped the metal so that it now grabs the fuse tightly.
-If you can find the original replacement fuse that's always the best way to go! Radio Shack sucks and will have all the fuses you could think of accept up to the one you need... so if you can't find the 10A 120v go with the 8A 240v like Radio Shack carries. I wouldn't go any lower than this amp rating unless you like changing fuses, and it HAS to be a SLOW BLOW, read the labeling! 240v is ok over 120v, it's just a maximum value, and you've already left less room for trouble than marshall did by going to 8A instead of 10.
-Before you patch it back together, plug it in, turn on standby and let it cook for 30 mins to be sure your fuse didn't blow for a different reason (Same symptoms with a different problem?! ...don't think it doesn't happen). And for Christ's sake if you got this far I know I don't have to say don't touch anything with it ON, but I will.
-By now you should be very relieved to see your beautiful tubes glowing again, and you missed that glow so much... Next I hooked a load to the speaker out and gave a brutal high volume/high resonance/high gain stress test with the amp in a good position to monitor the fuse just repaired.

Well, if it lives then you just won! Put it back together, flip your guitar store the middle finger and don't forget to unplug the soldering iron!

*Note-If you're worried about the 2amps less rating on the fuse, I taped the extra fuses to the inside of the amp in fear the 8amp fuse would not hold under all situations and might need a quick replace... but 2 blaring hard rock gigs and countless practices later, she's holding just fine. If you can't handle taking the small risk of a DIY repair, I'd recommend bringing it to a local repair shop, don't ship your amp cross country just for the few bucks you save on warranty. It may come back worse than it left.

rjohns1

Are you sure the original fuse was a 10A? That sounds a little high for a tube amp. I might be wrong but I remember an old thread about the fuse size for a Marshall head, granted it was an older head, but the size was I think 3A? I don't really see why a newer head would that much more current to run. I know it has more bells and whistles, but that is mostly solid state circuitry, for controlling the digital pots and saving the presets. How many tubes does the 410 have? Just playing Devil's Advocate here, I have not seen the 410 on the bench in person, I'm only throwing caution to the wind.

American Viking

hmmm... Don't take this the wrong way, but checking fuses is one of the very first things you should check when you have an amp problem. Always look at the easiest things first.

Never replace a fuse with one that is not the correct value. This is a big NO NO. Also, are you positive these are slo-blo fuses? I have never in my life put them in a guitar amplifier. I've only seen slo-blo's on Mesa's before. Either way, you need to correct that problem and find the correct value of the fuse and replace it immediately.

Finally, there is no reason to let the amp "cook" for 30 minutes. It only takes 30 seconds for the heaters in the tube to warm the electrons up enough to prevent them from shock when turning the amp on or in play mode. Why would you ever turn your amplifier on without a load connected? That is suicide for the amplifier and is killing the transformer. Of course if the amp was in standby the whole time that no current will travel through the tubes or OT but still, why run the risk?

I see you are kind of new here but I just wanted to tell you to be careful before you start spewing bad info like that. If you can't find proper fuses from Radio Shack then Napa, Advance Auto Parts, Auto Zone, Wal-Mart and many other places carry fuses all day long. Again, don't take this the wrong way because I'm not trying to be mean, but if you were stumped by a blown fuse then you may not be in the position to be telling people proper methods for amplifier repair.

Get the proper replacement fuse as soon as possible.

__________________


Transformers inside amplifiers were not originally designed to be in there, and the tube was not created for the guitar amp.
ANY recommended idle current is a guideline and in no way a necessary requirement. There is no skeleton key for any tube amp.

American Viking

Also for future reference to anyone else...

If you have an amplifier problem that typically starts out with loss of sound here is the beginning of the process for finding the problem...

1. At the first sign of a problem you do not recognize turn the amplifier off to prevent further damage. Fuses blow as a fail-safe to protect other components within an amplifier but do not necessarily guarantee full protection overall.

2. Check the easiest thing possible, fuses. Check the HT and MAINS fuse then if the amp is newer it may have fuses on the PCB itself. Especially Canadian issue amps as the electrical standards for the country are more stringent.

3. Check all preamp and output tubes for signs of problems. Cracks in the glass, getter flash that has turned white means that the vacuum seal is broken. Red plating is something else to look for. If you are the owner of a tube amp you should always have a full backup of tubes for your amp. There is no excuse not to have them. It's the equivalent of changing the oil in your car, if you do not maintain it, the car will stop running.

4. Check the load connected. If one speaker blows in a 4x12 you may never notice as good as any of us think our ears are. The open coil in one blown speaker is enough to throw the resistance of the cabinet to hundreds, possibly infinite ohms/resistance. This is going to likely result in blowing fuses, or worse, frying your output transformer. Too high a resistance causes electricity to become stuck in the transformer with no place to go until if fights it's way out by punching through it's insulation and windings, ultimately relating in your transformer's demise. It is important to learn to check speaker and cabinet impedance with a multimeter, also to learn proper methods of impedance matching.

These are just the easiest things to check to start off with. 99 out of 100 amplifier problems are tube related and are simple fixes. The things I have mentioned are basics that every tube amp owner should know. In many ways the tube amp is like a car, if you do not know how to properly operate and maintain it, it will die on you. Unfortunately no one tells us how to safely and properly operate and maintain our amplifiers when we purchase them and some of us have to find out the hard way.

Good luck to all in the future and happy new year.

__________________


Transformers inside amplifiers were not originally designed to be in there, and the tube was not created for the guitar amp.
ANY recommended idle current is a guideline and in no way a necessary requirement. There is no skeleton key for any tube amp.

clydey

i am new to the site but would like to add a couple of points and if anyone wishes to correct me fell free and please. i am in uk so dont know if the american version differs
the jvm410 has 4 *el34 and 5 * ecc83 aka 12ax7
all fuses are 5*20 mm type (250 volts) slowblow
at the rear of the amp, where the mains lead enters, the value of the mains fuse is displayed.i believe this is 2 amps uk and 4 amps usa . at this point there is a pullout cartridge containing 2 fuses. the one going furtherest into the amp is the mains fuse and the other is a spare so if you have a mains fuse going down insert the spare .never insert anything other than the correct value.
i believe that all the inside fuses are slowblow but check with a call to marshall.
inside the amp on the pcb there is 3@1 amp fuse and 1@500ma fuse and
(2*10 amp fuses supplying the heater circuit for the 4*el34 and 4 of the ecc83).these (valves) are parallel wired so that if any of the above valves heaters goes open circuit the other valves will still glow. the other ecc83 which is the first valve in the signal chain has its heater supplied by a neg 12 volts separate supply.i believe to eliminate noise (hum).
all the valves in the handbook v1 v2 etc do not correspond to the schematic v1 v2 etc i think i read somewhere that this was done during final design stage but not rectified on paper
i also believe that in later marshall 410 (those manufactured after 27 th week of 2007 )had the 10 amp fuses bridged out.there is a mod sheet from marshall for this.
there is a jvm 410 forum (different site) where the guy who designed the 410 for marshall helps out (santiall)
never work on the amp with it plugged into the mains
always drain filter caps.
i am sketching out the signal stages of this amp including the switching (relay and logic sides) and building up the info to help out so any corrections or technical advise anyone has to offer will be most welcome

JimmyPage

Definitely 10 amp fuses, these are the ones inside the amp on the PC board AFTER the transformer, not in-line with the 120v before the transformer. They seem to be supplying the heater circuit as clydey mentioned above^; and the replacement IS OK because it's of a lower value and has yet to show any signs of weakness at ridiculously high levels which I'm completely incapable of even utilizing during realistic day to day use. And they are definitely slow blow, it's unmistakable, the slow blow is wrapped with something to apparently help it facilitate some extra heat before melting.

@Viking:

Sorry for the misinterpret, the amp was left to "cook" (I just like that word for glowing tubes) in standby, nothing more. This is really just a ritual of mine, I feel it is arrogant to go with a questionably lower rated fuse and/or make ANY repair and just go straight to a fully assembled powered and loaded run. So, just for karma I took it slow and just made sure there wasn't, for some crazy reason, really more than 8amps surging through that new fuse. This also needed to be done while it was still open so I could verify the contacts were no longer heating up due to resistance. This way if it didn't handle it, power was not lost again in the middle of a load if the fuse would blow. Yes I would've put a load on it just for the hell of it, even in standby, but that damn cabinet is all the way across the house from the work bench and I've got back-ache issues from that thing already. I was extra mindful of accidentally hitting the switch to ON during the time.

As for stumped by a blown fuse, you didn't read^
This was NOT a blown fuse. The electrical smell should make you weary of just changing the fuse that blew without determining a cause.
The fuse was visually still in tact, the extreme heat from the loose connection at one end of the fuse actually caused the solder to liquefy and run away from the cap, opening a gap between it and the filament. Serious damage occurred to the area of contact and also to the copper tracer on back side of the circuit board from the heat. It continued let current pass without overdrawing 10 amps. Replacing the fuse and ignoring this just would not do. And honestly, I feel better about the lower amp rating fuse as long as it handles more than what I need for a long duration, why do I need to go back to the higher amp rating? I don't recommend it, but there's a risk warning in my post. My situation merited a desperate test with the 8A fuse so I could play the gig days later. I was careful to make certain no over exertion was being put on the new fuse.
My only uncertainty was the 240V rating, which I was then assured would not be a problem. The 240V rating simply gives a maximum safe voltage factor, this deals with the gap when the fuse blows. A lower than 120V fuse would still blow at the correct amp rating, but would leave a small enough gap for an arc to continue to complete the circuit. Using a greater than 120V fuse is fine. It still blows at the rated amps, it just leaves a bigger gap after the blast.

Just to be jokingly frank... The show MUST go on! The fans got the face-melting rock they deserved. Screw the equipment risk. I was in no danger with a fuse that will act faster now. I say risk blowing the bastard up if it could mean the difference between playing the gig with the big Marshall or settling for the mediocre backup Peavey amp whilst I scour the globe for the perfect fuse... That's me... and there are more of me out there.. this kind of post is for us and the headache we face too often living in fear of warranties and the nonsense we get from having to find equivalent parts and methods to fix things in a world that is growing increasingly more scared and less tech-savvy due to the false idea that they are helpless without a "qualified servicer". If you can read and process logic, you can do just about anything yourself with help from people who post on internet forums and websites. I wouldn't have learned a lot of what I know if not for some people with balls posting the reality of a situation they took by the horns. Like I said.. just being frank. As a senior member here you've got your place posting warnings too, I'd hate to hear about the fool who just decided to throw in a piece of copper tube in place of a fuse with his bare hands with the amp on blazing away under no load because he didn't read my post right. But for the guy at 2am waiting to play his first gig in years tomorrow night who is freaking out about the fact the he only has 8amp fuses in his hand and is running out of time... if you're up this late reading this just to get some clear facts from a real situation and a push to do it- here it is!

American Viking

word up!

__________________


Transformers inside amplifiers were not originally designed to be in there, and the tube was not created for the guitar amp.
ANY recommended idle current is a guideline and in no way a necessary requirement. There is no skeleton key for any tube amp.

clydey

just checked the current draw from an old tube book
el34 is 1.5 amps times 4 valves = 6 amps
ecc83 0.15 amps times 4 = 0.6 amps
total amps 6.6 amps
(valve 1 the first valve in the chain gets its heater current solid state)
but when you switch on from cold you get a surge voltage (xtra current draw)
later marshalls are modded for no 10 amp fuses
and a mod sheet provided for the earlier amps to i believe bypass the 10 amp fuses
if any of the techs have got the mod sheet perhaps they could publish it for us
i will give marshall a phone this week to see if i can get hold of it
but i dont know if they will release it to me as in the UK they have no marshall service agents

clydey

240 volt fuse against 120 volt fuse
the 240 volts means that the max voltage across the fuse that it is designed to operate at is 240 volts
now in the uk we would not put a fuse in that was designed for 120 volts
where 240 volt was specified
in the above case a fuse with a higher voltage rating (VOLTS not AMPS)
is perfectly ok

JimmyPage

"later marshalls are modded for no 10 amp fuses
and a mod sheet provided for the earlier amps to i believe bypass the 10 amp fuses "


Clydey:

Are you saying it may be ok for me to bypass these? Am I misunderstanding? If there's no real present danger in the circuit to necessitate the fuses I would surely like to phase out the weak link. It was a most disturbing scenario.

Thanks for the additional amp draw info, glad to have real evidence I'm close enough in spec not to have to sweat it.

clydey

yes spoke to marshall this morning
at switch on app 8 amps is flowing (due to the heater resistance of the valves which changes with temperature) and then settles down to app 4 amps.
marshall are bridging these two fuses with 16 guage tcw (tinned copper wire)
this wire MUST BE SOLDERED to each ends of each separate fuse (i believe it may be better to do it on the other side of the pcb but your choose
ie bridged
BOM (bill of material)
2 small strips of 16 guage tcw (tinned copper wire)
4 tidy solder joints
they dont have the mod sheet but explained it to me
hope this helps

JimmyPage

Thanks, it definitely helped! That's the most useful piece of info I've received on this amp. The possibility of the troubled fuse connection repeating during a performance has been a major worry in my mind that will now be eliminated.

Much appreciation for this Clydey!

clydey

not a problem
i am only standing on the shoulders of giants
but cheers anyway

www.extend-yourlife.com

I think you should check first when you have an amp problem. Anyway i wish you good luck and hope it works

JimmyPage

I think since everything's fine for the moment I'm gonna wait 'til I get a hold of a digital camera to mod the fuses. That way I can post the pics here. I'd like for people to see the original damage, too. Other out-of-warranty JVM410H owners need to see why this is an important mod.