TV/VCR/Stereo Troubleshooting/srt-de705 blows fuses


QUESTION: srt-de705 blows fuses I know the out putswere bad mn2488 what else should I check and the right side never work

ANSWER: Yes, probably the audio power output transistors need replaced.

Also, for aged receivers like this the electrolytic capacitors in the power supply are always suspect.  Lytics are the shortest life components in electronic circuits.  Look for swelling of the case and sometimes electrolyte seeping out near the terminals.

That's my advice for starters.  Good Luck.

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QUESTION: audio power output transistors I replaced them all rdy juust dint know if I need to check the small ones on it and what oms should they read

ANSWER: I am worried about your installation of the mn2488 transistors. They must be mounted to the heat sink and a mica washer treated with silicon grease is needed for electrical isolation and heat transfer.  Are you certain they were installed correctly?

And did you check the lytics in the power supply? That is very important.

Ohm readings will not mean much at the output section; better take voltage readings ; maybe compare one channel against the other.  That will at least say if one channel is likely still bad.


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QUESTION: if it was blowing fuses how would it have power to check voltage and I fix computers you put less then .380 of a inch of tork on them and I installed them the same way they came out

You may need to disconnect the dc voltage line(s) to the audio power out stages and see if the power supply now comes up.  You may even need to disconnect the big electrolytics in the power supply to keep it from blowing fuses.

Try that.  You've got to find out what is causing the fuse to go.  

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