Bugera 333 XL Infinium problems.

[Ramtheman]

Well got my Bugera 333 Xl a week ago and yesterday I plugged in amd was playing I did notice some crackling here and there So then the sound just declined and eventually gave out which led the standby light to start flickering as well as the 4 red led lights in the back completely on.
I did power off the amp waited half an hour and restarted it. This time no sound what so ever just the same standy light flickering and the infinium red led lights on.
Has anybody had this particular problem with their bugera amp.

[nickb]

Sounds like a bad connection in the power supply. First thing to check is try a different power lead and make sure it's firmly plugged in.

On line help is going to be very limited due to a lack of schematics for these.

What test equipment do you have and what is your level of experience?
Please update your profile with your location as this helps us to direct you to local resources if need be. Thanks.

[bob p]

> Sounds like a bad connection in the power supply

I suppose that the problem could also be outside of the PSU proper, and in the bias control board. The infinium amps have a separate bias control computer that's PIC based. It would pay to check all of the jumper cables, just in case you should get lucky and find a bad cable connection somewhere.

If you lose one of those bias control cards in an Infinium amp then you may be SOL; Bugera won't offer support services or sell their parts. In that case your only options are: SMD board level repair; find a board from somebody who is parting out an amp; or convert the amp to an old-fashioned manually adjusted bias supply.

[Ramtheman]

I went ahead and took a look at it I see no burned connectors not wiring. I also checked my fuses and they are all good. The amp itself powers on what I do see is 3 pre amp tubes lighting up on my power tubes none light up What so ever.So I'm guessing a transformer may have malfunctioned.

[nickb]

I went ahead and took a look at it I see no burned connectors not wiring. I also checked my fuses and they are all good. The amp itself powers on what I do see is 3 pre amp tubes lighting up on my power tubes none light up What so ever.So I'm guessing a transformer may have malfunctioned.

I would still suspect a connection in the power supply. What you have said narrows it down to the AC heater circuit. Transformers don't go intermittent, well I've never seen one in decades. Start measuring the ACV along that circuit until you find where it's open.

[Ramtheman]

Oh ok yea I'll look into that as well. I'm thinking about having it looked at buy a tech and see if they can fix the problem.Its a good amp and I'm loving the tone being on a budget helps the affordability.

[Steve A.]

I'm going to assume that this is a used amp because otherwise it would go back to the store under warranty. Is there any recourse with the seller or was this a special "as is" deal? If the latter if it turns out to involve proprietary circuitry which is not available one option might be to rewire it, like if it is related to the Infinium circuit replace it with a normal bias circuit.

Steve A.

[bob p]

It would be interesting to know the build date on your amp. That's on a rear panel sticker. Early on the Bug amps had a problem with a power supply to PCB connection that would routinely fail. If you're getting preamp filament warmup but not power amp filament warmup, then trace along the AC filament wires like Nick suggested. Chances are that you might find a carbonized connection where the low voltage line feeds the heaters. Those amps are known to do that.

[Enzo]

The Bugera connector problem only occurred on the first models, and even then only on early production.

That problem was the Molex type connector where the PT plugged onto the circuit board. Their solution was to solder the wires to the Molex pin headers on the board. They made the change in production, and sent out a bulletin instructing us to change any existing units we encountered. It was to be a warranty repair even if the amp did not come in with the problem.

[bob p]

was it on the HV lines or the heaters?

[Enzo]

five pin connector, the heater pins burnt up. But whole connector was snipped off and hard wired. This was the transformer wires, so it ought not be selective preamp versus power amp tubes.

The whole bulletin was very detailed, even down to how the styrofoam blocks went into the box and where the footswitch, manual, and power cord belonged in the box. All in case you were opening new in box units for the change.

[Ramtheman]

Update guys well I decided to take it to a tech and he found thr problem in which you guys were right and this was his diagnosed.voltage leaking on the filament supply that caused circuit protector to blow prematurely that's why I need to let it run for an hour or so.
He now has the amp running as we speak to ensure it doesnt give out.