Marshall Mode 4 schematic

[pbdog]

I'm looking for a schematic for one of these.Thanks pb

[Merlinb]

You'll be lucky, I tried and failed to get a schem too! Why not sell it and buy a real amp?

Anyhoo, the only useful piece of info I can give you is that Amp1 uses the valve closest to the FRONT of the amp, and amp2 uses the valve closest to the BACK of the amp.

[Enzo]

What is wrong with it? When an output module fails, they tend to fail as a team. And a burnt output module sometimes damages the mute circuit on the main board. Either the diode shorts or the transistor, possible the cap.

[pbdog]

4 modules replaced & blowen already.

A friend of mines Son blew his mode 4 again.So like a good father he loaned "The Kid" his jcm 2000 100 watter."He'll never get it back".He wants to fix and sell.How would I go about getting a schematic? Thanks Enzo .pb

[Enzo]

Send me an email with MArshall Mode4 MF350 as the subject line and ask for the drawings.

By the way, the amp is a MF350, Mode4 is just a series like JCM2000 is. You might find the schematic more easily looking for MF350.

My dealer page doesn't recognize Mode4 even, but it knows MF350.

If it is blown up, there are four of the power modules. They all use the TDA7293V. They are parallel in pairs. If you find only one bad, and just replace it, the others will fail soon after. Just bite the bullet and replace all four when fire happens. If it doesn't make sound - but the fuses are OK - after that, then the mute circuit got damaged on the main board.

Mouser sells them for $5.78 each.

If charcoal happens under the chip, I have never seen any of the little caps on the tiny power module board go bad. SO replace teh chip and be done with it. If a trace burns, patch it with a jumper wire.

tmenzo at msn dot com

[pbdog]

Thanks Enzo.

Thanks pb.

[Enzo]

The link you sent me came back as delivery failure. Please send an actual email and I will reply with the prints.

[pablocarrillo]

mode four schematic

Hi; i just have one mode four of a friend; and all four 7293v are burned; then i replace fuse; and replace all the IC,s

Preamp from input to send is ok; but no sound fron the poweramp.

Does anyone have the full schematic of this amp???


Thanks to all, and sorry about my bad english...

[jknopp2]

please send the MF350 Schematic.
Thank You,
John Knopp Jknopp2@twcny.rr.com