Bugera 6262 problem please help !! Desperate.

[MP4-22]

Hello, I've been searching the forum and google for a similar issue and i have only found one person with a similar issue regarding a 333xl. My 6262 is switching from the lead channel to the clean channel at it's own discretion. I saw a similar issue being reported with a Bugera V22 and they state to put a heatsink on the 7815 regulator, I tried this and it didn't work so i went ahead and change the IC1 and IC2 position with new 7815 and 7915 regulators. I still have the same issue.

I am confident now after disassembling and soldering these two regulators i have the ability to fix this but i do not have the ability to fig out what is wrong. I am very disappointed in my efforts failing.

Please if you have any advice ideas on what to try i'm all ears, please help. I'm begging.

I have the schematics but i don't know how to properly understand them etc...

If anyone knows a repair shop in NY/long island that's good i would a appreciate that too. Thanks Gentlemen and Ladies.

The one member that had this issue with the 333xl never posted back what the fix was. I like when people report back with the solution but unfortunately this member did not.

Don't know what happened to the thread i just made... weird..

[Danglin' Fury]

Hey guy. Welcome. There should be a discrete board where the footswitch plugs in. On said board, you will find a couple of transistors that will surely be bad. I had a problem with a Peavey Triple XXX doing this. change those and your problem should go away.

[MP4-22]

Thank you, I sent it into repair earlier today but i'm gonna try that if they can't fix. Thank you so much.

[MP4-22]

Yesterday it was bugging me so i cancelled the repair. I took the amp home and inspected the area you suggested. I saw this...



I know nothing about electronics really but you mentioned a transistor... I didn't see any of those (google imaged it) but i did see the R54 resistor looking crooked compared to the other 2. So i fig what the heck it's easy access. went to radio shack matched the picture i took bought the resistors and changed R54. The issue appeared to be solved but after 2 hours it did it. but it's doing it alot less frequently.

what do you think ? I'm super thankful for your help danglin' fury!!

[Danglin' Fury]

Follow the wires from the footswitch jack. they should either lead to some transistors, or some traces that will eventually connect to them. I will look at my schematic and try to be more specific. Oh, and please be careful. tube amps have voltages in them that can kill you! Seriously. even when its off. The manufacturer probably has cap bleed resistors but still, watch what you are doing in there. If you have never worked.on a tube amp before, The switching is kind of a big deal and it may be better to let somebody that has done this before to do it for you. My suggesting the transistror was in the vein of you having worked on tube amps before. but, since you told me you had to google what a transistor is, it may be better to start your troubleshooting career on something that WONT kill you.

[MP4-22]

I knew it could kill me, I've had bunch a tube amps. I know what the the capacitors are etc. I really appreciate your help.

[Danglin' Fury]

Ok. Sorry if I sounded condescending. Just didn't want you to cook yourself. Just follow the lines coming out of the footswitch jack and you will run into 3 transistors. Those should be the culprit.

[MP4-22]

Ok. Sorry if I sounded condescending. Just didn't want you to cook yourself. Just follow the lines coming out of the footswitch jack and you will run into 3 transistors. Those should be the culprit.

Na, it's all good i appreciate the help alot.

DF, are these the 3 transistors your mentioning ? T6,T2, and T3 ? They are labeled A06 transistors on the PCB. If these are them where can i buy them ? Is 2n3906 the same type of transistor ?

http://www.radioshack.com/product/in...uctId=2062585#

[Danglin' Fury]

Those are your huckleberries. Really, any NPN transistor will do that can handle at least 80 volts. That is what the data sheet rating is on this particular part, so I would stick to that. You can probably find one at Digikey.com. Or see if you have any local parts stores. NOT Radio Shack. I only say that because here in Tulsa, Ok. the Radio Shack's don't have much of a discrete parts selection. NPN is VERY important.

[Danglin' Fury]

Those little guys from Radio Shack will not work. The 2N3906 is a PNP transistor. The A06 is an NPN.

[MP4-22]

Unfortunately radioshack is all i got. Will this NPN transistor work as a replacement handles up to 75v, i think ?

MPS2222A Transistor : Transistors | RadioShack.com

[Danglin' Fury]

I think those will do fine. Before you get those, look at the boards and all the solder points. Make sure all the solder is good, as in, all points are soldered well and there are no solder bridges. But yes, those MPS2222A fellas should get you up and runnin'.

[Jazz P Bass]

The Radio Shack MPS2222A will work fine.
Make sure it is the 'A'.

[MP4-22]

Cool DG, thanks so much. I'm gonna give it a go and see how it works out. I already checked and the solder points look normal as far as i can tell. Any idea if i should just change one at a time or all three. Any idea on which of the three is prolly the culprit ?

[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.