Sony CFS-99 dead after potential wrong voltage

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SpaceLobster

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Hello,
So I have this Sony CFS-99 I've been working on for along time now.. Bought it a while ago and it worked fine on batteries. Then I decided I should try to use the plug and I had a shaving cord that seemed to fit. But it was the wrong voltage and I think it caused some problems, and the boombox didn't make any sound after that.. Then I bought some new innards and circuit boards from Japan. And now I have finally put those new ones in but now it's completely dead.. I don't know of any fuses etc or where the damage would be from the wrong voltage, someone said sound board. I checked all the connections and it looks good but nothing happens when I turn it on. What could be wrong, where should I check ? I can provide alot more details and pics but this is the basic problem.

Peace
 

JVC Floyd

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Have you tried a different cord.
If you have a spare power supply that's the right voltage you could use it to power up the main board and see if the problem is the transformer board.
 

nikonfoo

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If the voltage overloaded the fuse may of saved you
there is a fuse soldered to the transformer its not obvious at first
take of the plastic cover that is over the transformer and you can see it
it is not mounted on the board
I will try to take photos tomorrow
nothing happening could be good news
lets hope its the fuse
:yes:
 

SpaceLobster

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I don't have a cord that fits, just the same one that broke it.. It does not power on with batteries. I can't get any life-signs at all. I looked at the transformer but I don't know what the fuse looks like.
Thank you for your replies.

Peace
 

nikonfoo

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docs

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When you find it on the power board near the transformer, remove it from its holder and use a multimeter continuity check and put the probe on either end, you should have continuity on a good fuse.

 

hopey

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Generally speaking the AC input can include a mechanical interlock which isolates the DC battery supply, These can be jammed in an open position so you get nothing.
 

SpaceLobster

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There is a fuse that looks like that. I don't know if its blown though. If it is should I remove it ?

How do I change this jammed position hopey ?

Peace
 

hopey

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Have a look at the orifice where the ac cable connects. There is a little lever that get depressed.
 

JVC Floyd

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First thing I would do is get a 12 volt test light and check the output wires from the power board and the battery compartment to see if power is even coming out of the power supply .
 

SpaceLobster

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This is getting complicated for me. I cant see any depressed levers Hopey, but I don't have any test lights.. What are the odds its something I can fix easily ? Like if there is no power from the supply it's not just replace one fuse right ?
Or should I just sell it maybe..

Peace
 

hopey

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Have a look at the ac input in the below picture there is a lever that is pressed when you insert the cable. When you remove the cable sometimes it doesn't lift back up.

AC DC Interlock.jpg
 

SpaceLobster

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hopey it's lifted back up. and from I can understand it wouldn't work to change the fuse either. so there is some more advanced trouble somewhere..

Peace
 

Line Out

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Have you tried using a power adapter?
In the power connector section there is more than a few contacts, that may oxidize and cause problems.
Have you tested the transformer, that it delivers voltage? If so, the problem seems pretty bad.
 
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