Yet another Bugera 333 XL - 212 fuse blows at power up

[TrajanGregory]

I do have the Infinium model, in this case.

When I first received this amp a few months ago, it worked without any problems.

Then one day, it suddenly died when I switched from the clean channel to crunch channel. I checked the mains fuse, and it was open/blown.

I acquired one single fuse from a local shop, and, then tried to power up again - I thought that maybe the problem was in the crunch channel side only, but the new fuse blew immediately in the clean channel mode, so it didn't need to switch to crunch to blow the fuse. I ordered a crap load of fuses to continue troubleshooting ...

Once the new fuses came in, I instead removed ALL tubes, and replaced the fuse again.

It again blew .... I do have a set of NON-Infinium schematics, and I am a Certified Electronics Technician, who has worked primarily in aerospace systems, so I can see that I will probably have the opportunity to demate connectors and isolate sections of the circuitry in order to locate the 'bad component'

Silly me, some months after I bought the amp, I threw away the box ... I don't have much room in my smallish apartment, and so it was in the way ...

I now regret that choice ... I may have to buy a travel worthy box in order to obtain warranty work.

On the other hand, this might be a great opportunity to learn about guitar amps, my first love before I started working in aerospace ...

If I continue and remove the chassis from the cabinet, I will most likely void the warranty, so, that's the choice I have .... find the problem, or find a box ....

Enzo? ... any advice here? ... The amp is on my kitchen table, and I have a choice to make ...

Anybody got a spare 333XL-212 amp box?

[The Dude]

1) Many companies do not mind and actually prefer you send in the chassis only to keep shipping costs down. I don't think sending it off without a cabinet would void the warranty, especially considering you haven't tinkered with anything yet.

2) Your post hints at wanting to fix the amp yourself and then goes on to the warranty issue. Are you looking for repair assistance, or just a box so you can send it in?

[TrajanGregory]

Well ... I am a little torn ... As a tech, I want to take it apart and figure it out...

But as an occasionally rational person, I think obtaining warranty work when I can is wise ...

So ... yeah, I'm torn ... But I'm not terribly stupid ...

Returning for warranty work is my best option.

I guess my next step will be contacting Zzounds, where I bought this little gem.

They will let me know what's what ...

[The Dude]

IMO, if the unit is under warranty, that is the best route. Let's say you start tinkering and find out it needs an expensive part like maybe a power transformer. You may void the warranty and have to pay for the part yourself if there is evidence that you took the thing apart. If you have trouble getting results from Zzsounds, you could also go directly to the Bugera warranty support page here and fill out the request.

BUGERA-AMPS: Support

[TrajanGregory]

Thanks Dude ... I appreciate it ... I'll come back with updates ... I like this little forum due to the intelligence I am seeing here ... I can learn a lot here ....

[52 Bill]

Welcome to the place.

Thanks Dude ... I appreciate it ... I'll come back with updates ... I like this little forum due to the intelligence I am seeing here ... I can learn a lot here ....

Here's a first lesson, fuses blow for a reason. After the first one blows, build yourself a light bulb limiter and save the other 28.

[Enzo]

Look at your schematic, the power tube plates are powered even in standby. Check for a shorted flyback diode between power tube plates and ground.

[J M Fahey]

Don't waste time, send it at once to Authorized Service.

Every day you waste, is one lost warranty coverage lost.

Having the option, even Mr Bugera himself would do that.

[Muskratt]

I do have the Infinium model, in this case.

When I first received this amp a few months ago, it worked without any problems.

Then one day, it suddenly died when I switched from the clean channel to crunch channel. I checked the mains fuse, and it was open/blown.

I acquired one single fuse from a local shop, and, then tried to power up again - I thought that maybe the problem was in the crunch channel side only, but the new fuse blew immediately in the clean channel mode, so it didn't need to switch to crunch to blow the fuse. I ordered a crap load of fuses to continue troubleshooting ...

Once the new fuses came in, I instead removed ALL tubes, and replaced the fuse again.

It again blew .... I do have a set of NON-Infinium schematics, and I am a Certified Electronics Technician, who has worked primarily in aerospace systems, so I can see that I will probably have the opportunity to demate connectors and isolate sections of the circuitry in order to locate the 'bad component'

Silly me, some months after I bought the amp, I threw away the box ... I don't have much room in my smallish apartment, and so it was in the way ...

I now regret that choice ... I may have to buy a travel worthy box in order to obtain warranty work.

On the other hand, this might be a great opportunity to learn about guitar amps, my first love before I started working in aerospace ...

If I continue and remove the chassis from the cabinet, I will most likely void the warranty, so, that's the choice I have .... find the problem, or find a box ....

Enzo? ... any advice here? ... The amp is on my kitchen table, and I have a choice to make ...

Anybody got a spare 333XL-212 amp box?

I have owned a Bugera 333xl 212 and if you are under warranty you might ask for a supervisor and see if they can either send you a box or ask if they can just send you a new amp and let you send the one you got back.
They offered me this option way back. You can also try a guitar store and find out what day they get the shipments in and see if you can get them to save a box and packing for a 212 size amp.

[The Dude]

If it were mine, I would ask about pulling and sending in the chassis only. Shipping would be much cheaper.

[Enzo]

Muskratt is right. If going for warranty, contact either the place exchanging or the warranty center and ASK how they prefer to handle it.

[TrajanGregory]

Bingo .... D4 shorted ... Replaced w/ R2000F ... sparkling tones once more ...

[Stratovarius]

Bingo .... D4 shorted ... Replaced w/ R2000F ... sparkling tones once more ...

I have the head version , no schematic but should be the same I think.
Mine blew the main during practice, then same as you , whenever I go to turn it on, tubes in tubes out, same thing... pop!!!
I find D10,11,12,13, then 19 somthing through 29 or so, but haven't found D1 through 4, did you have to unscrew the 3rd pcb to find yours ?
Bugera will not let me see a schematic, it might be under warranty still but I don't have the box either and may have
a heck of a time finding warranty card.

[Jazz P Bass]

D1-D4 flyback diodes are connected to each EL34 pin #3 & then all go to the B+ (Designation 'F')

I don't know what "the 3rd pcb" is, so you will have to trace it out.

Bugera 333 xl Flyback diode.pdf

Complete file: (BDM1) Bugera 333 xl.zip

[Stratovarius]

D1-D4 flyback diodes are connected to each EL34 pin #3 & then all go to the B+ (Designation 'F')

I don't know what "the 3rd pcb" is, so you will have to trace it out.

[ATTACH]34828[/ATTACH]

Complete file: [ATTACH]34829[/ATTACH]

I'm referring two the board that holds the el34's , it's mounted so the componenets are hidden, I have to
break the factory goop on the screws to look at it, and will do so.
The pdf you provided shows the section very well, Thanks!
I have tons of 4007's I'm sure , don't remember every having r2000f's, it's worth ordering
and not substituting on this do you think, shotkey = ?
I need to lift one side of each diode to get a reliable reading don't I, I'd also be happy to chg them
all out, but would also like to know for future.
I don't find Germanium r2000f's on ebay , is there a supplier that will sell me them without
a $35.00 etc min order that you know of?

Thanks a ton...



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