Troubleshooting Problems

MP1 - Developed very loud hum on tube settings

Started by MR THUD

Replies: 8
Views: 3,928

August 29, 2022, 11:38:14 AM
by MarshallJMP

No sound on select preset channels and weird output level knob behavior

Started by Andrew Smith

Replies: 2
Views: 3,937

March 07, 2018, 04:22:32 PM
by Andrew Smith

Bad buzz or rumble on mp-2 high gain modes

Started by h.e.l.shane

Replies: 2
Views: 4,125

July 14, 2014, 09:43:55 AM
by W.Laturno

Hum and Crack on DIST mode

Started by Jonar

Replies: 3
Views: 4,139

August 31, 2014, 01:28:19 PM
by MarshallJMP

MP-1 Classic dead

Started by tangohf

Replies: 4
Views: 4,298

December 07, 2014, 04:50:19 PM
by MarshallJMP

MP1 and Cold Exposure

Started by Chip Roberts

Replies: 2
Views: 4,429

December 10, 2017, 08:17:01 PM
by herbyguitar

error codes

Started by Mike_Revis

Replies: 3
Views: 4,503

March 27, 2014, 03:45:20 PM
by MarshallJMP

Mp-1 v2 mod 3 no output in tube anything

Started by bunkyloo

Replies: 10
Views: 4,528

October 05, 2018, 02:16:17 AM
by rnolan

MP-1 full refurb and restoration

Started by Systematic Chaos

Replies: 4
Views: 4,573

November 23, 2022, 07:09:05 AM
by MarshallJMP

MP1 1.38 - Is my Chorus failing???

Started by skarkowtsky

Replies: 11
Views: 4,647

May 09, 2021, 02:50:58 AM
by MarshallJMP

No Distortion on the Distortion Channel

Started by Misticmyst73

Replies: 2
Views: 4,767

December 05, 2013, 04:44:31 PM
by SidecarJoeG

Programming patches - inconsistent behaviour

Started by MikeB

Replies: 4
Views: 4,808

March 18, 2015, 09:39:15 AM
by MarshallJMP

front panel

Started by kserri

Replies: 3
Views: 4,812

December 03, 2018, 01:11:27 AM
by rnolan

MP-1 diagnosis

Started by willem

Replies: 4
Views: 4,828

December 02, 2014, 10:55:53 AM
by MarshallJMP

V1.38 gain drop/loss just seconds after startup / warmup (solved)

Started by Systematic Chaos

Replies: 11
Views: 4,859

October 28, 2022, 07:26:03 PM
by rnolan

MB-1 no output

Started by peoriashows

Replies: 7
Views: 4,905

July 28, 2018, 11:51:45 PM
by rnolan

MP1 Classic Clean Issue

Started by AndiK

Replies: 7
Views: 4,974

May 01, 2019, 04:06:36 AM
by MarshallJMP

Ground hum noise

Started by dave_daut

Replies: 5
Views: 5,069

April 08, 2014, 08:45:59 AM
by rnolan

Front panel don´t work

Started by kserri

Replies: 5
Views: 5,181

January 30, 2015, 04:21:33 AM
by rnolan

Clicks when switching presets

Started by sadky

Replies: 6
Views: 5,328

October 03, 2014, 05:47:22 AM
by Systematic Chaos