RCA boombox

Discussion in 'Audio' started by Taruno, Jul 12, 2018.

  1. Taruno

    Taruno

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    On my RCA boombox Mod. # RP-7991A one speaker stop working, is it repairable?
     
    Taruno, Jul 12, 2018
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  2. Taruno

    davenn Moderator

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    possibly
    are the speakers detachable ? Do they have their own plugs on the back of the unit ?
     
    davenn, Jul 12, 2018
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  3. Taruno

    dave9

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    Possibly. Open it up and play some audio, measuring whether there is AC voltage on the speaker wires, similar voltage to the left side. If there is, the speaker is probably blown.

    If there is not, you can trace the audio circuit backwards from the speaker, measuring for the AC signal, where it stops in the signal path.

    If it uses a chipamp, you might find that it is easier to use a currently produced product rather than hunting down old stock (which might even be counterfeit) and if it has a different pinout, using jumper wires from the PCB to the pins on the new chip. If it needs wires, try to keep them as short as possible.
     
    dave9, Jul 12, 2018
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  4. Taruno

    Taruno

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    No, unfortunately they are integrated to the unit. Thanks for your concern, though!
     
    Taruno, Jul 12, 2018
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  5. Taruno

    Taruno

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    Thank you, Dave! I'll try that this weekend (I work full time).
     
    Taruno, Jul 12, 2018
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  6. Taruno

    dave9

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    In some cases I've seen speakers held in by 3 or 4 little metal tabs that can be unscrewed, but in other cases I've seem them held in with what looked a bit like rubber cement. If it's the latter you may have to cut the cement the best you can, and pry to get it out, then cement in a new one IF the speaker is bad. It might help to heat the cement with a heat gun or hair dryer. Keep in mind that for left/right balance, both volume and tone, if you have to replace one speaker you ought to replace the other, unless you just want the cheapest repair possible.

    If you'll be running this off batteries, or it's the amp subcircuit that's damaged, something else to consider is ditching what is probably a class A/B amp, to a class D amp board off eBay. They're reasonably cheap (under $10 delivered?) for the low wattage you'd need and would make more efficient use of the batteries.
     
    dave9, Jul 12, 2018
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  7. Taruno

    Taruno

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    Thanks Dave! I'm printing your solutions for this weekend.
    I really appreciate your advise,
    Taruno
     
    Taruno, Jul 12, 2018
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