Marshall JVM410H JS Foot s/w issue

[Arbutt]

Hello
I customer dropped this in to me. His daughter was playing about with the amp and pulled the foot s/w lead out suddenly and foot sw then stopped working.
The controls on the front work perfectly, He went off and bought another foot s/w but not the JS version which won't work.
JVM410HJS Main Circuit Diagram.pdf
So however i have the amp here, checked the circuit
i have 4.2v on the D105
11.8v supply and 10v on R123 ( 150R)
diodes test ok.
TR101 tests ok
As i had one of the Zvn4424 in stock ( don't remember why ) i changed it
still the same

The foot s/w is the original and not lighting up. Tried to check over the best i could , all looks ok

I don't want to buy another foot s/w as expensive and if it don't fix it, its more cost to be added on
Marshall spares said they can't supply me as i have a spares acc only

at power on there is no LED's on the foot s/w that light up, all switches on the panel work perfectly and reverb
so my thinking is .... IC105 is ok??
I ain't uploaded the rear panel where the foot s/w jack is. as it just the jack socket and a couple of beads and coils

many thanks
Mr A

[Jon Snell]

Check IC2 output. Depending on the suffix, there should be corresponding output voltage. No voltage, no lights and it won't work.

[vintagekiki]

I customer dropped this in to me. His daughter was playing about with the amp and pulled the foot s/w lead out suddenly and foot sw then stopped working.
The controls on the front work perfectly ... ...

The schematics midi controller VM410H is missing.
Proper operation of the controls on the front work indicates that the midi controller in the VM410H is working properly.

Check the connecting cables from the foot controller (sw) to VM410H that they are not break.
Check solder the jacks, and probity the jacks on the foot controller (sw) and on the VM410H.

[J M Fahey]

Just checked with a friend of mine whoīs my "go to" for all things Midi, who manufactures MIDI controllers here in Argentina and he told me you are not *stuck* to the expensive original Footswitches, as an example some of his customers have that Marshall amp model and contol them (and lots more stuff) from his Universal/Programmable MIDI controllers, no need at all for the original FSW.

hereīs a free sample of fine Argentine Industry:

https://maxcontrol.com/sp/products/fcx-8/

[nosaj]

Juan, it's always interesting when you post something from your neck of the woods and how you guys tackle the same problems .
nosaj

[Arbutt]

Thanks I have check the connections are OK and lead is. I've put out a call to a friend who has a Joe satch head. To let me check the foot sw. To buy another foot sw from Marshall via a retail shop will add another Ģ100 will a little on for me. Or I could go with the jm farey midi pedal and spend Ģ418 + postage or $540. Hardly an option I think.
As the foot sw is classed as finished goods its not available on a spares acc

[Jon Snell]

Thanks I have check the connections are OK and lead is. I've put out a call to a friend who has a Joe satch head. To let me check the foot sw. To buy another foot sw from Marshall via a retail shop will add another Ģ100 will a little on for me. Or I could go with the jm farey midi pedal and spend Ģ418 + postage or $540. Hardly an option I think.
As the foot sw is classed as finished goods its not available on a spares acc

But the faulty parts are!
Fault find and repair.

[Arbutt]

But the faulty parts are!
Fault find and repair.

thanks jon. But the bloke has bought a standard jvm foot s/w that wont work. ok not my fault. The amp is in for 4 x new power tubes, I don't mind charging him for a foot s/w if it works, But don't really want to say, " yeah i bought a new foot s/w but its not that, but im still going to charge you for it?? that is ok i think if its a few quid , but even if i charge cost its still over Ģ70.
waiting to check with friend who has one.

[Jon Snell]

If you can try a known working pedal or, a bit cheeky, try the pedal in the local amplifier store on a known good amplifier.
Not sure where you are situated but there are lots of stores around the UK that have amps in stock. If you get nowhere I am in Weymouth if you need a hand.
If the pedal is not at fault, remove the amp from the box, check the +5FP supply and check the switching lines are working (from the output inwards to the pedal socket), if it was OK and when unplugged hasn't worked since, seems a little strange.

[Arbutt]

I spoke to Marshall tech today they confirmed it is the pedal. Have ordered it through a shop and we shall see

[Jon Snell]

Seems a shame to purchase a new pedal as it is only 6 touch switches that send a ground to the microcontroller; ATTINY2313A if it is not a pulled ground wire in the pedal and ATTINY2313A

are only Ģ0.86p each, assuming the regulator has not failed at a further Ģ0.88p from RS, both of them are available.
At least as Marshall pointed the finger at the pedal and if it turns out not to be the fault, they will accept it back for a full refund.

[J M Fahey]

Or I could go with the jm farey midi pedal and spend Ģ418 + postage or $540. Hardly an option I think.

Oh, I was not trying to sell you *this* one, by any means, or any other; rather emphasizing that you are not stuck to that single trick pony of a pedal which does not even work on other models of the same amp BUT suggesting that a Midi Controller, ANY midi controller can supplant it.
And thatīs important to know.

Imagine in 5 or 10 years the proper pedal is NOT available, at any cost ... what will your customer do? Junk the amp if he needs one?
Stop a solo to push front panel buttons with his pick?

To be used just as a pedal , for a single amp, yes, a programmable Midi Controller is overkill.

But the idea behind it is that it can control a ton of stuff ... even stage lighting if you program it so and lighting controlles has MIDI input, go figure.
Now such a controller price starts to sound cheap

In fact, I guess a Tech could test *any* Midi controlled amp (or keyboard , or effects, or ... anything) at his own shop without needing all the different dedicated pedals.
Even if after checking function he orders the individual ones

EDIT: canīt your customer send the useless (for him) pedal back?
Maybe not getting a cash refund but credit towards future purchases?
Absolute worst case, he should EBay it, *somebody* will need one.

[vintagekiki]

I spoke to Marshall tech today they confirmed it is the pedal. Have ordered it through a shop and we shall see

Why don't you ask Marshall tech if they can take over the faulty foot controller for repair.

[Arbutt]

Marshall UK said we don't repair them. I'm hoping to keep hold of it for further investigation and possible repair

[vintagekiki]

I'm hoping to keep hold of it for further investigation and possible repair

https://music-electronics-forum.com/forum/amplification/guitar-amps/maintenance-troubleshooting-repair/913456-marshall-jvm410h-js-foot-s-w-issue?p=913480