Marshall MB4210 Owners - Your Help Required

[GT40Graham]

Hi All,

I've just done my first gig with my Marshall MB4210 combo and MBC115 speaker cab. Unfortunately I was a victim of the amp overheating scenario which I now find has been a regular topic on here (teach me to research properly before buying). Anyway I've checked everything and can't find any loose components/poorly soldered joints but what I have noticed is this - I think the fan on the amp is blowing the wrong way! I could be wrong about this but the fan on my amp is sucking air into the amp but I think that it should be drawing air out. The reason that I think this is because the amp chassis has grilles on the bottom so I would expect the fan to PULL air in through the bottom grilles and be exhausted through the fan. If it was supposed to work the other way around I would expect the grilles to be on the top of the amp (hot air rises, cold air falls etc).

I will get in touch with Marshall tomorrow but if possible, could any MB4210 owners check your amps and let me know which way the fan blows.

Regards,


Graham.

Edited August 8, 2010 by GT40Graham

[leonshelley01]

Just checked, mine sucks air in rather than expels it. I've never experienced this over heating issue, but Marshall have always been very helpful when contacting them about my dodgy Valvestate guitar combo, give them a ring.

[GT40Graham]

[quote name='leonshelley01' post='918827' date='Aug 8 2010, 04:20 PM']Just checked, mine sucks air in rather than expels it. I've never experienced this over heating issue, but Marshall have always been very helpful when contacting them about my dodgy Valvestate guitar combo, give them a ring.[/quote]

Thanks for checking. I'll be in touch with Marshall tomorrow and see what they say.

Regards,



Graham.

[Ancient Mariner]

It makes sense that it would suck cool air in from outside and blow it directly onto the components on the circuit board, rather than draw it in from underneath. Warm air from electrical components won't rise very much relative to a cooling fan blowing it around, and will be insignificant by comparison.

[GT40Graham]

[quote name='Ancient Mariner' post='918998' date='Aug 8 2010, 08:01 PM']It makes sense that it would suck cool air in from outside and blow it directly onto the components on the circuit board, rather than draw it in from underneath. Warm air from electrical components won't rise very much relative to a cooling fan blowing it around, and will be insignificant by comparison.[/quote]

Hi,

I hear what you're saying and you're probably right but the layout does seem all wrong. The fan blows onto a large aluminium heatsink which is situated above the vents in the amp chassis so the air is exiting the amp from underneath the fan, seeing as hot air rises it seems to me that the fan will then recycle the hot air that has just exited the amp. If the amp had vents on the top then the fan sucking in would make more sense.

If the fan was pulling air out of the amp it would still pull cool air in but from under the amp and the hot air would exit via the fan.

You would assume that Marshall have tested all this but the fact that there are many reports of this overheating problem does give cause for concern.

Regards,


Graham.

Edited August 8, 2010 by GT40Graham

[Lozz196]

[quote name='GT40Graham' post='919013' date='Aug 8 2010, 08:16 PM']Hi,

I hear what you're saying and you're probably right but the layout does seem all wrong. The fan blows onto a large aluminium heatsink which is situated above the vents in the amp chassis so the air is exiting the amp from underneath the fan, seeing as hot air rises it seems to me that the fan will then recycle the hot air that has just exited the amp. If the amp had vents on the top then the fan sucking in would make more sense.

If the fan was pulling air out of the amp it would still pull cool air in but from under the amp and the hot air would exit via the fan.

You would assume that Marshall have tested all this but the fact that there are many reports of this overheating problem does give cause for concern.

Regards,


Graham.[/quote]
Hi Graham

I had the 4210, and have the 450H (though sale agreed for this) and never had any problems with either. However, in my dealings with Marshall, they have been great - real customer service, the type we used to have, before automated telephone lines etc. So I`m sure that they will manage to sort this problem for you. Depending on where you are, if you can get to Bletchley, I`d advise booking the amp in to coincide with one of their tours around the factory. That way, it gets checked out, whilst you see what goes on in Marshall HQ. Not many companies offer this.

Lozz

[munkonthehill]

I had the combo on it's own, infact I had 2. Both failed on me, one whilst I was at a gig!!!!

I got an exchange sorted for a h&k and never looked back.


My advice is get shot of them, they are so unreliable I can't believe they are still being sold via stockists.


IMHO of course!!