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Post subject: Blues deville drive channel problem
Posted: Mon Oct 20, 2014 2:59 pm
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Hi all,

I have a '93 American 212 Blues Deville. It has recently developed a problem where by when i change to the drive channel, the amp seems to get stuck between the drive and normal channel, and the "volume" knob (which normally is disabled on the drive channel) seems to control the volume some what, aswell as the "master" and "drive" knobs. This issue seems to happen after ive been playing for 10 minutes or so.

I have read that the resistors R85 & R86 could be the problem, and they can develop cold solder joints? I have already had this amp in the tech shop when it died and turned out to be bad caps which cost me £85, so id like to do it myself. I have a schematic but as I look at R85 & R86, they dont seem to have anything to do with channel switching;

http://www.blueguitar.org/new/schem/fender/blues_deville.gif

Does my porblem sound like a resistor or resistors have got bad connections?


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Post subject: Re: Blues deville drive channel problem
Posted: Mon Oct 20, 2014 4:26 pm
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R85 and R86 are in the supply which provides power to the op-amps that control channel switching, reverb and the loop. Cold solder joints, or broken circuit traces, around those resistors is likely the cause of your problem. You have to disassemble the amp, remove the main board, touch up the joints and/or repair broken traces, then reassemble. Be careful when removing the main board, do not flex the ribbon cables, where they meet the circuit boards, enough to disturb the solder joints.

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Post subject: Re: Blues deville drive channel problem
Posted: Tue Oct 21, 2014 10:41 am
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Do you know where I can get instructions or a video to explain how to do this?


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Post subject: Re: Blues deville drive channel problem
Posted: Tue Oct 21, 2014 1:01 pm
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If you need a video, you are better to see qualified tech

1- tube amp have lethal voltage even it is disconnected
2- Ribbon cable must stay in same position. if you move them they could make some noise
3- Printed circuit copper are fragile , you must know how to solder and desolder
4- Blues Devill is kind of tough amp to fix if no skill


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Post subject: Re: Blues deville drive channel problem
Posted: Tue Oct 21, 2014 4:37 pm
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stratele52 makes some very good points.

When starting a job like this, the amp should be unplugged from electricity, then measure the DC voltage across the large capacitors to be sure that they are discharged (around 20 volts or less is fine).

Unplug the amp from electricity.
Remove the back cover, check that the caps are discharged. Discharge using an approximately 100 ohm, 5-watt resistor, from the positive of each cap to ground if necessary.
Remove all knobs and the nuts and washers under the knobs.
Remove the nuts from the jacks.
Cut the wire ties on the transformer wiring on the left, to allow the main board to move more easily.
You might need to push the reverb cables through the chassis hole for more length if necessary.
Remove the screw for the green ground wire (on the right?)
Remove the six black screws that hold the main board to the chassis.
Carefully lower the board down to clear the pot shafts from their holes and swing the top outward to access the solder joints. Be careful not to flex the board.
Inspect all solder joints and traces, use a magnifier for a good close look.
Touch up any joints that need attention, and bridge any broken traces.
Reassemble in the reverse order of dis-assembly.

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


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Post subject: Re: Blues deville drive channel problem
Posted: Wed Oct 22, 2014 1:53 am
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Before working on ; takes many close ups of the ribbon cables .

This amp series is one f the toughest amp to work on for a beginner and many techs


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Post subject: Re: Blues deville drive channel problem
Posted: Wed Oct 22, 2014 11:55 pm
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Thanks fellas. By the sounds of it this isn't a job for me. I don't have a multi meter or any resistors to dissapate the caps. I've heard these amps can be unreliable and $@!& to work on and now I'm seeing why. Wish I had bought the peavey Classic 50. Never mind. Thanks again.


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Post subject: Re: Blues deville drive channel problem
Posted: Thu Oct 23, 2014 2:13 am
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lodgi wrote:
Thanks fellas. By the sounds of it this isn't a job for me. I don't have a multi meter or any resistors to dissapate the caps. I've heard these amps can be unreliable and $@!& to work on and now I'm seeing why. Wish I had bought the peavey Classic 50. Never mind. Thanks again.



A 1993 amps with is first ( ? ) problem after 20 years, unreliable ???

Are you kidding :lol:

See a qualified tech and you'll be good for long time :)

Most if not all modern amps ( or any mass products ) are not easy to work on . Peavey is not better , I have one .


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Post subject: Re: Blues deville drive channel problem
Posted: Thu Oct 23, 2014 2:50 am
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stratele52 wrote:
...A 1993 amps with is first ( ? ) problem after 20 years, unreliable ???

Are you kidding :lol:

See a qualified tech and you'll be good for long time :)

Most if not all modern amps ( or any mass products ) are not easy to work on . Peavey is not better , I have one .


+1 stratele52

If you think that the BDvl is difficult to work on, then a Peavey Classic xx would be a nightmare for you. Instead of ribbon cables, Peavey uses individual small pieces of bare, solid wire to connect three boards. The three boards are arranged as three sides of a box, and all of the solder joints are underneath the boards. I would rather work on a BDvl than a Peavey any day. Don't get me wrong, Peavey's are nice amps, and I have a Classic 30 myself.

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---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


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Post subject: Re: Blues deville drive channel problem
Posted: Thu Oct 23, 2014 3:20 am
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I write ; " Peavey is not better " .

I work often on these amps . Yes they are nightmare

By the way ; I don't like Peavey sound


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