MXR Phase 90 Pedal Logo

Related Topics:

Anonymous
Anonymous Posted on Apr 30, 2010
Answered

How do I fix a mxr phase 90 (overvoltaged!with 12V universal)

I just would like to know, how do I fix a mxr phase 90 which went dead after I overvoltage it with a 12V power supply(it's a non-regulated power supply, I accidentally push the switch to 12!).
i've done some googling, and found the schematic but still don't really get it. your help is really much appreciated.

Answer This Question
  • 1 more comment 
  • Anonymous Apr 30, 2010

    lol, looking at thesehttp://picasaweb.google.com/lh/photo/823...
    http://picasaweb.google.com/lh/photo/ZXw...

    looks like something is fried. btw, do you happen to know the part name for that input thing?

  • Anonymous Apr 30, 2010

    cant i just use a pen-multitester?when i checked it using my pen-multitester, it appears everything is working, i mean the LED of the pen-multitester lights up for every "solder bottom" it touches. weird!

  • Anonymous Apr 30, 2010

    cant i just use a pen-multitester?when i checked it using my pen-multitester, it appears everything is working, i mean the LED of the pen-multitester lights up for every "solder bottom" it touches. weird!

×

1 Answer

Anonymous

Level 3:

An expert who has achieved level 3 by getting 1000 points
Superstar:

An expert that got 20 achievements.
All-Star:

An expert that got 10 achievements.
MVP:

An expert that got 5 achievements.

  • Master 4,234 Answers
  • Posted on Apr 30, 2010
Anonymous
Master
Level 3:

An expert who has achieved level 3 by getting 1000 points
Superstar:

An expert that got 20 achievements.
All-Star:

An expert that got 10 achievements.
MVP:

An expert that got 5 achievements.

Joined: Mar 17, 2008
Answers
4234
Questions
2
Helped
1564380
Points
12312

My first guess would be that the zener diode is probably shorted. Also check the 2N4125 transistor for a short. Start there and update this with your results.

Dan

Testimonial: "fast response!"

  • Anonymous Apr 30, 2010

    The large part is the input or output jack and is not the problem. Unfortunately neither the zener nor the transistor will appear defective. You will need a diode checker to determine the problem. If you don't know anyone local, try locating my ad here on Fixya for direct contact. Perhaps I can help further.



    Dan

×

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

0helpful
1answer

MXR phase 90 swtiches on but I have no phasing
I would check the difference in sound between using an AC adapter and a battery. These things lose the effect when the batteries get low.
Read full answer
Mar 28, 2014 • MXR Phase 90 Pedal
0helpful
1answer

My old MXR phase 90 sounds weak (amplitude) and the frequency (range) of the sweep is rather narrow. Can you hep?
First thing to check is the battery or the adapterr.
Read full answer
Jul 24, 2011 • MXR Phase 90 Pedal
0helpful
1answer

I have the MXR EVH Phase 90. When plugged in, and unit is off my sound is fine. When unit is activated, the light comes on but there is no sound. The same thing is going on with my Maxon AD999 Delay pedal....
The fact that it happens with 2 different units may point to something in common. You just first eleminate the cables as a possibility by swapping. Also, most pedal problems can be traced to a battery issue, so make sure it is a good one. Make sure you are using mono, not stereo cables.

The footswitch could be faulty, try holding it in different ways to see if it makes contact.
Read full answer
Feb 27, 2011 • MXR Phase 90 Pedal
0helpful
1answer

I'm experiencing an unwanted gain boost when using this pedal
If using another pedal in the loop, change the orrder
Read full answer
Aug 21, 2010 • MXR Phase 90 Pedal
0helpful
1answer

Is there some sort of trim pot or something in the block letter phase 90 where I can turn the volume boost down when it's on. I don't hate the sound of it but it gives me too much gain when I click it. I...
Have you tried experimenting with the order of your signal chain? Have a look at this link:http://www.zimbio.com/Guitar+Boomer/articles/36/How+Choose+Correct+Signal+Chain+Order+Effects
Read full answer
Jul 02, 2010 • MXR Phase 90 Pedal
0helpful
2answers

Bypass is fine, LED lights when active, but signal is very low in volume when effect is active. Almost inaudible.
Make sure power voltage is adequate. If using a battery, the LED will light LONG after the batteery is beyond usability.
Read full answer
Jan 17, 2010 • MXR Phase 90 Pedal
0helpful
1answer

MXR Phase 90 doesn't phase only clean signal. The oscillator is working and I have changed the BJT's.
sounds like a switch contact problem, try some surgical alcohol. (for the MXR not for you!!!)
Read full answer
Dec 31, 2009 • MXR Phase 90 Pedal
0helpful
1answer

Phase 90 dead no led no nothing- it has tl062 and a tl064 chips block script, switch seems good on VOM, can the 2 diodes after the power input be likely problems? I can also swap out the IC chips for...
One needs to consider the history of the unit. Could someone have used a reversed power adapter? If so they probably blew those diodes.

Input power protection diodes are often in the 1N4004 family.

Do not change any diodes without knowing the type. There may be Zeners as part of the effect shaping.

Check the power getting to the Op amps... pin 8 and 4 are the power pins, 8 being positive. Don't get fooled as sometimes the circuitry has the positive as signal ground.

ONLY SHOTGUN a device as last resort.
Read full answer
Dec 11, 2009 • MXR Phase 90 Pedal
0helpful
1answer

Turns on, led works, just suddenly stopped applying its awesome phase 90 effect though.
If you are using battery power, just because the LED lights doesn't mean the battery is adequate. Check the battery voltage.

If you are on adapter power, make sure any bypass switch is in right state. Also occassionally someone gets the in's and out's cables backward... that can do it!
Read full answer
Nov 09, 2009 • MXR Custom Shop Phase 90 Led
0helpful
1answer

Mxr phase 90 block logo and the 9v power jack not working
These break and SOMETIMES the circuit board gets cracked.

Open up and inspect for damage. If board is cracked, bridge broken traces by soldering wires around the break.

If the solder is broken, resolder it.

If the connector is damaged or weak spring, replace the connector.
Read full answer
Sep 12, 2009 • MXR Phase 90 Pedal
Not finding what you are looking for?

View Most Popular

Phase 90 Pedal

  • Music

Related Question

MXR phase 90 swtiches on but I have no phasing

  • MXR Phase 90 Pedal

Related Topics

1,066 views

Ask a Question

Usually answered in minutes!

Popular Questions

MXR phase 90 swtiches on but I have no phasing

MXR Phase 90 Pedal

Bypass is fine, LED lights when active, but signal

MXR Phase 90 Pedal

MXR Phase 90 doesn't phase only clean signal

MXR Phase 90 Pedal

Mxr fullbore metal does not power up on battery or 9v adaptor....foot switch, diode?

MXR Music

I have the MXR EVH

MXR Phase 90 Pedal

Top MXR Music Experts

Brad Brown

Level 3 Expert

19187 Answers

john h

Level 3 Expert

29494 Answers

ADMIN Andrew
ADMIN Andrew

Level 3 Expert

66949 Answers

Are you a MXR Music Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...