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Changing Main Board on DSL100

Discussion in 'The Workbench' started by OdgeUK, Apr 29, 2012.

  1. OdgeUK

    OdgeUK Member

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    Hi All,

    A while back I offered to retube and bias a friends DSL100, not because I'm a tech but because I have a Bias Probe and have done some light work on my old JMP amps at times.

    We found that the bias on the amp began to rise way above the suggested bias value after the amp had been played for 20 mins or so. We did a lot of elimination testing to ensure the fault wasn't following a bad tube etc and came to the conclusion that the tubes were fine (we used another set of tubes as well from an amp of mine).

    Having heard that the early DSL boards (his is late 90s) are prone to bias drift due to thin PCB board material and thin traces, we decided that rather than employ a tech to investigate, it would be more cost effective to order the replacement / revised board from Marshall for £70, which apparently does away with these issues.

    Tomorrow, we are going to attempt to swap the board. An initial look seems to indicate that no soldering is required, it's all plugs, so it seems straightforward if not a little tricky. If we get the board in ok, we pretty much plan to Bias and fire her up.

    Does anyone have any tips / warnings advice before we start this? Something that might save us some time or headaches?

    Thanks
     
  2. D-Max

    D-Max Member

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    Label the connectors - on both the old and new board - and cables.
     
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  3. keef1367

    keef1367 Well-Known Member

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    + 1 on this advice and I personally would take pic's too just to be on the safe side :)
     
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  4. sneakyybstrd

    sneakyybstrd New Member

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    Just curious how things went and what was the total cost? Did you replace all of the boards or just the main one with the electrolytic capacitors on it?

    Im think about doing this too. :\
     

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