Hello friends,got this sent for repairs.No power.Check there's no secondary coming out from that tiny transformer.Never bought such component before nor have any idea about its type and data.I don't know what those numbers stamp on it means.

Would appreciate any info about it. Thanks.

Hello all,its me again.My apology

I'm troubleshooting this unit.Its distorted both channel.The output is low too.This is a second unit.I failed the first one last year.I gave it back due to my lack of time a.k.a I'm slow.

The problem come and goes.Feeding to return seems ok and I think it the preamp but I don't know where.I feed a 440hz sine wave for tracing on a on and off basis as the reading on my scope is ok(I think).Plugged in the guitar to play and trace at the same time is hard to do but that's when the problem can be heard.Is there a common spot at the PCB to focus on about this symptom.?I as much like to solve this with the help of you guys.My Marshall success repair is low.Trying to get back doing it good again.My amps encounter has few and much fewer when I started to do more guitar repairs.Those pays the bills quicker than amps.Hope most of you with such experience could give me pointers.


Thank you

Hello all,long time no post.

I have this Laney sent in after the authorized service center could not fix it.The owner took it back and came to me.I'm not an expert but would like to do my best.Hard to say no to circuit porn.

To begin with I opened the amp found a diode was put back wrong near the power amp tube circuit,I'm unsure what else was done to it.However the inside doesn't match the LC30 service manual I have.They have redesign it all.I'm not good with reading it without SM,I'm unsure whether I'm asking for right version as well.I think its version 3.Anyone here has the service manual to share.It would make a good reference on the bench.Would like to be alive after that too.hehe

Thank you sir.

Hello,I came across a Line 6 spider III 3012 that has power power problem,upon checking and comparing with spider II schems,I found some similarity between the two for voltages checking.

upon looking at it I didn't saw op amp near the EQ controls,then I found that they use codec.I am no codec expert but I don't like this,my work came to a stop.There's no such codec in my country.

Who else is using this codec IC?
I don't believe codec is equal to the hard working op amp,trannies etc.
Its a good way to kill us small time tech.

what do you think fellas?

hello..I'm trying to understand this.
lets say we have 2 amps and its gonna be like a shoot out or sound comparison.
both are identical solid sate type except for the power amp section.

amp A has LM3886t(found out about this when repairing Vox AD30VT yesterday)

amp B has maybe 2 BD909 or combination of 2 PNP+NPN power transistors that will produce the same watts as amp A.

Thank you all.


one more
what is equivalent to BD909(saw in laney hc30r schematic)

Hello to all,its been a while..I almost forgot my password on the way here..again I need help sourcing the mentioned subject.I've emailed them but no reply..and again I'm being chase by the client.

hello fellow forumer,i'm new to this forum thing,i dont know where to put this.I need some help,i have this H&K Attax 40 arrive for repair.wondering anyone has schematic or direct me to the site that has it.
Thank you and god bless you all.