Mesa Boogie Recto-Verb Twenty-Five Problem

[Travis8]

It´s doesnt work, it´s dead.

When I changue the fuse it´s work but he stop working fast.

Some time ago a technical changue the transformer becouse the problem was the same.

2 years later again I must changue the transformer???

Some help please?

[tubenit]

Do you know how to safely work on tube amps?  IF not, please consider taking it back to an amp technician.

IF you do know how to safely work on a tube amp, then:

1)  post high resolution pictures of the chassis interior
2)  post voltage readings on the tubes
3)  describe exactly what the problem is prior to blowing fuses.  When did it stop working?  And are you aware of anything
     that happened prior to it not working? 

Have you tried new tubes?

Do you know how to set the bias of the tubes?

IF all the tubes are removed from the amp, does it still blow fuses?

It would be unusual to have to replace a power transformer. It's possible to need to do that but I would guess something else is the problem.

With respect, Tubenit

[Travis8]

Yes im used to repair amps, but never a mesa boogie... I will take some pictures later.

[SILVERGUN]

I had one of these fail and it was because a trace on the board had become intermittently open.
It was the filament circuit and I could see it happening because the indicator lamp would blink and then go out after the amp started getting hot.
When I opened the amp up I could see where the trace was burnt and lifted. I got lucky and was able to repair the trace by using some wire to jump across the affected area.

[Travis8]

Here is some photos

[Travis8]

The fuse is ok now but it doesnt work, it doesnt take on

[dpm309]

You need to use a light bulb limiter. If you don't have one, they are very easy to build and you will find instructions on this website. That way, you will  not keep blowing fuses and can narrow down where you might have a short etc.

[Travis8]

But the fuse is ok, sorry I said bad in the first post.

The problem with the fuse was in the first reparation when the other technical changue the transformer.

Now its doesn´t work but the fuse it´s ok.

[Latole]

I agree with Tubenit to ask if you know how to fix.

Read transformer 's secondary voltages and you will know about transformer.....

 I can't find this schematic. I'll use the 22 Calber for voltage.

https://el34world.com/charts/Schematics/files/Mesa_boogie/Boogie_22cal.pdf

[tubenit]

Now its doesn´t work but the fuse it´s ok.

Please answer the following questions so we can help you.

Have you tried different tubes? 
Have you tried a different speaker?
Have you tried a different guitar and guitar cord?
Are you getting any noise from your speaker?
Have you taken voltages on the tubes plates, grids and cathodes?  Can you share those please?

What was it doing prior to not working?  Was it making any noises?  Was there some intermittent problem?

Please look at these helps on this website for trouble shooting:

- in ARCHIVES    https://el34world.com/Forum/index.php?topic=21999.0

- https://el34world.com/Forum/index.php?topic=19361.0

With respect, Tubenit

[Travis8]

Just I doesnt work, is not the speaker or valves.
The light doesnt turn on, I will read values from tubes later

[Travis8]

Also when I turn ``on´´ the tubes doesnt get voltage, becouse they all off.

[Latole]

Also when I turn ``on´´ the tubes doesnt get voltage, becouse they all off.

You mean NO heaters voltages ? Tubes don't glow ?
Read voltage at transformer secondary

[SILVERGUN]

Amp is dead:
1) Is there power to the power switch?


2) Is the power switch working?


3) Is 120V making it to the PT? (check tightness of ribbon cable connections) I would be very suspicious of these


4) What voltages do I have on the secondary of the PT?


5) Etc...
6) Etc...

[Latole]

Yes im used to repair amps, but never a mesa boogie... I will take some pictures later.

About transformer and power supply ; all amps are same.

What you write, it is a basic issue. The problem is Mesa amps are a nightmare to work on

[Travis8]

Amp is dead:
1) Is there power to the power switch?


2) Is the power switch working?


3) Is 120V making it to the PT? (check tightness of ribbon cable connections) I would be very suspicious of these


4) What voltages do I have on the secondary of the PT?


5) Etc...
6) Etc...

Let me look and I answer this questions

[Travis8]

Sorry I can't do It before.

The transformer it's not working.

Do you know Where can I buy one from Europe?
I don't know how to find the original transformer. Thanks. :)

[Latole]

8 months later......Welcome back.

You are sure you have some 240 volts going in the primary ?

You may read some output voltage at heater or B+
Or primary winding is open ????

Read ohms at each winding , you must find a open one or more than one.

Finding a Mesa PT in Europe ???? You may order one from a Mesa dealer ?

Picture for winding only ;

[Travis8]

Primary doesnt works

[Latole]

Primary doesnt works

Do you read ohms ? How many ?

[Latole]

Some dealer in Europe for Mesa B parts

https://www.banzaimusic.com/search.php?mode=search&page=1&keep_https=yes

[Travis8]

The primary is broken, my friend is so good with amps he open and saw that the problem is in the winding.

So I must replace it but I don´t know how to buy the original one.

Thanks :) I will take a look from banzai

[Travis8]

Mesa Boogie said this to me: The part number of the Recto-Verb 25 220-240V power transformer is 561841


Can I use this one? https://www.tubeampdoctor.com/en/mains-transf.-for-mesa-boogie-transatlantic-ta15

[Latole]

Mesa Boogie said this to me: The part number of the Recto-Verb 25 220-240V power transformer is 561841


Can I use this one? https://www.tubeampdoctor.com/en/mains-transf.-for-mesa-boogie-transatlantic-ta15

I don't know, you have to find the specs of the original one.
Do you have the schematic ?

Tubesamp doctor PT is the same Mesa Boogie part number, he must fit. How can we be 100 % sure ?