Quote from: joecool85 on March 08, 2012, 08:38:34 AM

Quote from: probodger on March 08, 2012, 07:42:16 AM
Ok better way of posing the question would be, what size are the cators for anyone who has a G100? As they are the pop-out type, so if I can get some that will retrofit then life will be easy.
I don't really fancy redrilling the old box unless I have too.

Pull one off, bring it to the hardware store, match it and buy four.

Thats my issue, I have zero 

I need to replace all four.

and not lugging this heavy beast to the store to match things up 

Ok better way of posing the question would be, what size are the cators for anyone who has a G100? As they are the pop-out type, so if I can get some that will retrofit then life will be easy.
I don't really fancy redrilling the old box unless I have too.

I also need some castors/wheels for mine.
Any ideas where I can get some from?

CAn't remeber what the power switching on the rear of mine is, but its something like 110/210/230volts I think.

Another mystery to me is why does mine have a different style knob to any other G100 212 II I've seen, I guess it's possible somone may ahve changed them in the past.

I guess you saw the other G100 thread? It's a Japanses market only version of the G100 - read it online when I got mine, but can't for the life of me find the page with the info on again.

Yeah I know, that confuses things more 

When you say B100, do you mean a G100 212 ??

like this?


If so search for G100 as from what I've read in the past, these amps were only listed as "B" in Japan, rest of the world knows them as G. You can find service manuals for them online plus the Yamaha site has the owners manual for the Series III version (final version of the model run)
One pictured is a Series II, I bought it a few weeks ago off ebay UK and it came with the mutilated Duo Sonic.

Killer deal as these amps are fantastic and always go under the radar. I need to refurb it a bit, there is a split in the handle and the EQ pots are scratchy, but I'm holdign out on taking it aprt just yet as I've only just got it.

Yeah I read that thread too, although I get no sound from the guitar just hum/buzz from amp.

I ahve yet to try "wiggling" those big capacitors to see if the humm/buzz changes.

And I'm guessing the TDA2050 IC is the one that is stuck on the back of that big aluminium heatsink thing as it gets hot.

Ok, just had a chance to try out the amp.

• Altering the pots, does nothing to the "hum"  - it's constant.
• Checking the speaker leads I get 0.5V on the 20V scale of my multimeter.
• Also noticed the "power on" indicator LED on the front of the amp, hardly lights up

Thanks!

I'm at work today and tomorrow so I'll be getting the multimeter out on Tuesday and will report back with my findings 

Easiest way to build your own first pedal (mine was a Systech Harmonic Energizer)is cheat slightly and get a PCB from  somewhere like Madbean.com or GGG. That way you will usually get a parts shopping list of components and detailed instructions on how to wire all the off board parts like switches at pots.

If you are going "try bypass" and using a 3PDT you can just find a diagram online (Beavis Audio is a good place) and use that to guide you as it will be more or less the same for the pedal you are building.


edit.. should read page 2 before posting, didn't see this thread had one lol

Quote from: tonyharker on December 03, 2011, 03:54:53 PM
Sounds like you've blown the power IC a TDA2050. Youll probably have to replace it. Could have been caused by plugging/unplugging the headphones? - Switching transient? TDA2050s are a bit fragile in my experience, I've blown a few!

Is there anyway of testing the voltages on that IC? Or is that a bit dangerous 

Actually what you have said makes a lot of sense, If I think about it, I've blown ICs in pedals using this power outlet and extension 4way... think I need to use a different one.

I'm at work so can't currently do a "live" test to answer the questions but from memory and what I tried at the time.

It's a low down buzz, kind a like "mains frequency" buzz.

Pretty sure turning any of the pots did anything, just constant "buzz/humm"

Guitar & leads work fine in other amps.

I was playing through it at low volume (its a brutal little amp even at low volume!!) and with headphones plugged in when it let go. probably had a fuzz pedal or two in the chain.

Never plugged it in to an extension cab or any other speakers - other than using headphones.

I'm aware about the dangers of capacitors etc - I've made a few of my own effect pedals and modified guitar circuits quite a bit but never had a go at attempting a repair on an amp before.

Hello all!

I've recently bought a Fender Frontman practice amp off ebay. it was fine for a few hours use but now all it does is buzz. It's doesn't stop buzzing/humming when the strings on the guitar oare touched/earthed either.

I'd like to fix it but don't know where to start. I've opened it up and the internal fuse is ok so I'm taking a wild guess it's a capictor or something that needs replacing.
Hopefully not a speaker issue??

Any suggestions/ideas welcome.

its  15watt Mexican made one, Model PR241 I think??