Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Rich on October 01, 2013, 03:54:32 pm
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Short of cutting a hole in the chassis, how do I get at them??
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I take it your saying they are under the PCB?
You probably have to lift the board out? Might have to disconnect some other parts/wires/wire clips/pots from chassis, to lift the board? Go slow, make a very detailed drawing of everything you disconnect and take a bunch of hi-res close up pics if you can so you can put it back together.
Brad :icon_biggrin:
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I have the slightly older Studio 22 and changed the caps in it a few years ago. I expect its remarkably similar to yours.
The board is mounted on plastic stand-off pillars that protrude through from the component side. You have to squeeze the ends that poke through with long nose pliers until the catch releases and then ease the board up over them. About 6 or 7 of them if I remember. You can then lift the board up enough without de-soldering all the wires to get at the filter caps.
Not great to work on, but I've seen worse!
Good luck
JB.
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Oh man, those were my worst nightmare when I did repairs.
I have seen the upside down tubes get so hot that they unsoldered resistors and the resistors fell off the board.
been many years since I worked on one so I don't remember the exact procedure but you have to lift the board and it is a royal pain
Good luck, charge double your normal rate on those bastards
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where i'd start - from looking at the pic below; remove the nuts off of the pot and jacks on the rear panel - board should lift up and out the way with parts still attached by their wires. you may have to clip off the wire ties off of the grey reverb cables and push the reverb cables up through the chassis hole. of course, disconnect the reverb cables from the tank first...
--pete
(http://uraltone.com/info/wp-content/uploads/2009/08/mesa_boogie_studio22_2.jpg)