Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: jukelemon on September 06, 2025, 11:59:22 am
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Hi all!
So this Blackstar Club 40 comes in. Power/Volume surging in and out.
Open it up and see 10 caps look to have exploded.
Getting high voltage when I probe the top of the power supply caps.
The "have you seen" question is this... I am ALSO picking up 250-400vdc when I probe that rust/brown residue.
It is as if the caps have bonded together on the top of the board?
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Wow! Looks like pancakes on the grill! Well, you know where to start at---might be a lot more to be found?
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---might be a lot more to be found?
Yeah...I am afraid that may be the case and that's a lot of time and money to spend for the customer.
These are known to have bad boards all the time and I am weary to repair these caps and then find another issue.
I may just buy another board if they are still available. I see them for ~200.00
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I may just buy another board if they are still available. I see them for ~200.00
Is that for an empty board? This could get unreasonably costly - you might want to check back with the owner first.
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I may just buy another board if they are still available. I see them for ~200.00
Is that for an empty board? This could get unreasonably costly - you might want to check back with the owner first.
Oh no no. Completed board i.e. literally a drop in.
It is what a service center would do in other words. The caps alone would run ~100.00 (I am not buying cheap caps like what came with it) so I think it makes sense IF he wants to fix it. I only posted a pic of a few caps. There are 10 that look just like these which makes me very suspect that other things are going on AND why I think a new board is the way to go as opposed to spending the money on caps only to then find out other components have failed-which is very very common on these amps.
If it were me...I would just buy another amp OR buy another used Club 40. They are 250-300 all day long on the used market. BUT he likes THIS one soooo who I am to judge :)