help ME!!!!

[xbox540]

hey guys i gotta problem......i own a AVT50H marshall head and i was playing it the other day and while it was on i disconnected one of the cabs and the fuse blew out. i contacted some technicians and they told me it might be that the IC chip or something blew out and to fix it it would cost around 50 to 100 bucks. is there any way to know for sure that its the IC chip by looking at the circuit board or does my amp just need a new fuse? (which by the way i bought new fuses for it and it just kept blowing them out).....thanks for any help

[Bigred]

these could be of some help

http://www.indyguitarist.com/schemat...vt50_60_02.pdf
http://www.indyguitarist.com/schemat...vt50_61_02.pdf
http://www.indyguitarist.com/schemat...vt50_62_02.pdf

[jaycee]

Your amp will now need professional attention because you replaced the fuse multiple times and they all blew, causing further damage.

[anatech]

Hi Bigred,
Thanks for posting those links!

Hi xbox540,
1/4" plugs and jacks short when you are inserting or removing the plug. So it looks like you need a TDA7293. The tube amps were okay with this happening for a short (ha ha) time. Solid state isn't as you found out.

Are you good at soldering? If not, get it to someone who is. If you damage the traces on the PCB the fun will just be beginning. You will also need some fresh (as in new) thermal compound. Don't over tighten the screws on the chip. If you do, the tapped holes will strip. You don't want to go there.

-Chris

[xbox540]

thanks for your help guys. yeah i guess ill have a tech look at it, just wish it wouldnt cost so much.......im seriously gonna start getting into working on amps and electrical stuff so i can learn to do these things myself cuz i KNOW that this is probably an easy fix but since i dont know for sure how to do it ill end up messing something up lol

[Bigred]

Originally posted by xbox540
im seriously gonna start getting into working on amps and electrical stuff so i can learn to do these things myself cuz i KNOW that this is probably an easy fix

Speaking of easy fix xbox, many "diy'ers" see a blown fuse and rush out to get a replacement or worse yet bypass with foil or something retarded (Do you feel lucky?). One simple lesson you can learn is to never just go replacing a fuse in electronics as it can lead to further damage and definitely disappointment. Sorry if I offend anyone but what is another dumb dumb is to keep replacing the blowing fuse expecting a different result.

[MikeW]

You can get the chips from Digi-key. I think $6. My son blew his up last year.

[anatech]

Hi Bigred,

Speaking of easy fix xbox, many "diy'ers" see a blown fuse and rush out to get a replacement or worse yet bypass with foil or something retarded (Do you feel lucky?).

Very good advice.

If anyone wants to play the odds, I'll help you out. If the glass on your fuse is heavily silvered or blackened, do not try another fuse. The chances are high that you will make things worse. If you can still see the wire and there is only a little "puff" on the glass, you may be okay to try another exact same fuse, that means a fast blow for a fast blow and not a slow blow for a fast blow.

Hi MikeW,

You can get the chips from Digi-key. I think $6. My son blew his up last year.

It's never the chip I worry about. It's the PC board. That's the most expensive component in there. One ham handed attempt is enough to write the amp off.

-Chris