Troubleshooting Problems

No Power, No Display, No Output

Started by Chip Roberts

Pages1 2 3

Replies: 38
Views: 18,315

December 23, 2017, 08:35:04 AM
by MarshallJMP

No Sound

Started by 2ndmoto

Pages1 2

Replies: 18
Views: 13,071

January 18, 2014, 05:50:06 AM
by MarshallJMP

no sound on outputs A and B, effects loop works

Started by ang3lus

Replies: 4
Views: 2,960

April 15, 2020, 01:27:32 AM
by rnolan

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

Started by Andrew Smith

Replies: 2
Views: 4,183

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

No SS voicing

Started by Tweeddeluxe1

Pages1 2 3

Replies: 41
Views: 928

June 28, 2024, 02:46:53 AM
by rnolan

Programming patches - inconsistent behaviour

Started by MikeB

Replies: 4
Views: 5,002

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

Rack grounding?

Started by Georgeclooney0

Pages1 2

Replies: 29
Views: 10,210

December 04, 2018, 11:07:57 AM
by rabidgerry

Rear Input Jack

Started by Jaster

Replies: 1
Views: 4,075

March 16, 2015, 04:05:22 AM
by rnolan

Solid State Clean Gets Nasty

Started by Moff40

Replies: 5
Views: 3,811

August 29, 2022, 09:34:51 PM
by Moff40

Sound issues after noise mod

Started by Deregorn

Pages1 2

Replies: 29
Views: 15,429

June 19, 2014, 02:41:35 PM
by MarshallJMP

Srange Chorus problem

Started by Pete66

Replies: 2
Views: 2,693

September 26, 2020, 12:43:27 AM
by Pete66

Troubleshooting hum and weird microphonics

Started by DesmoBob

Replies: 5
Views: 5,833

July 01, 2015, 05:51:55 AM
by rnolan

U.S. MP-1 Repair

Started by kfowler8

Replies: 5
Views: 5,821

September 06, 2016, 06:28:36 PM
by kfowler8

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

Started by Systematic Chaos

Replies: 11
Views: 6,027

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

Very OT: Refrigerator repair

Started by vansinn

Replies: 12
Views: 7,608

July 12, 2016, 12:50:14 PM
by vansinn

Very Strange Behaviour

Started by MikeB

Replies: 4
Views: 6,169

June 12, 2015, 03:21:17 PM
by MikeB

Viper probs, info moved from Schematics section

Started by guitardude57

Pages1 2 3

Replies: 32
Views: 16,289

June 02, 2017, 03:28:21 AM
by MarshallJMP

Viper trouble

Started by Dante

Pages1 2

Replies: 18
Views: 14,865

May 05, 2018, 01:24:28 AM
by MarshallJMP

Wrong channel comes up on my MP-1

Started by Darth Infernus

Replies: 9
Views: 7,103

May 22, 2015, 01:36:41 AM
by rnolan

[Solved by MarshallJMP] MP1 doesn't start up - mysterious blinking

Started by hal2000

Pages1 2

Replies: 21
Views: 14,769

January 27, 2014, 10:03:05 AM
by MarshallJMP