Bugera 6262 problem please help !! Desperate.

[Enzo]

The A06 transistor is an MPSA06 type.

Note th bases of those transistors are controlled by the same current that lights the LEDs. When this thing changes channels on you by itself, do the lights change too? If they do, it is more likely the problem is on the DSP board. The channel switching logic is on that DSP card. Try giving thast little card a bit of flex to see if that triggers unwantedresponse.

And have you explored the push buttons? WHichever channel comes on by itself, watch the voltage sitting on its non-ground side, compare to the other two switches.

[MP4-22]

Thanks Enzo and Jazz p bass, I will try flexing the dsp board to trigger a issue. The lights do change with the channel when it switches. I changed t3 and t2 with new transistors still have the issue. i'm gonna try the flexing to trigger a issue before moving on to t6 cause its a PITA.

[Enzo]

My guts tell me those transistors are not the cause. I'd be suspecting an iffy solder joint on one of the 100-legged ICs on the DSP board.

[MP4-22]

So enzo you got me thinking about the switches... i hit them with my air compressor front to back and it's holding channels and behaving. Could dust be the culprit ?... after all this frustration solder transitors and resistors..... i hope so. fingers crossed going on 90 minutes hard playing and channel switching, no issues.

[daindm]

What happened with your switching prob? Was it just dust?

So enzo you got me thinking about the switches... i hit them with my air compressor front to back and it's holding channels and behaving. Could dust be the culprit ?... after all this frustration solder transitors and resistors..... i hope so. fingers crossed going on 90 minutes hard playing and channel switching, no issues.

Hi - I know it's been 3 yrs but can please tell me if your channel switching prob is fixed. Was it dust - I notice there's no posts I can find after this last entry so maybe it was? I am having same prob with my 333-212 Combo. For a while it was only doing it at practice sessions but it's done at the last couple of gigs - which I've temporarily got around by setting my Zoom pedal to similar distortion and volume on clean channel as the Crunch channel and let jit do it's thing regardless but I love this amp and really want to use it's full potential again.
How about an update, mate, thanks. (Aussie, living and jamming in Sri Lanka)

[bahr]

just same problem with my bugera 6260-212, the channel is switching by itself. Actually when the amp getting hot, about 30 minutes after start on. Anyone have solve this problem?