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AVT50 Repair
AVT50 Repair
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Old 23rd July 2012, 07:06 PM   #31
j4976 is offline j4976
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Join Date: Jun 2012
Could you be more specific?
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Old 23rd July 2012, 11:29 PM   #32
Enzo is offline Enzo  United States
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Join Date: Sep 2004
Location: Lansing, Michigan
As it sits it makes loud hum. That is almost always either DC on the outpout or bad filter caps. DC will make the speaker cone move one direction and stay there. If it does that, TURN IT OFF. Disconnect the speaker. If it doesnlt do that, we move on.

Never connect a speaker to an amp until you knoiw it is not making DC on the output. Measure for DC voltage between the speaker wires while it is running. Should be none.

If no DC offset, then you have probably lost filtration. even if you replaced the caps, there may still be a bad connection to them or a cracked solder or circuit trace connetion.

The AVT50 uses the little power amp ICs TDA7293 on the very small circuit board mounted to the heat sink. Fan cooled. The little circuit board with IC I call a power module. It connects to the main board via cable. If there is DC on the output wires, than almost certainly this TDA7293 is bad.
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Old 24th July 2012, 01:05 AM   #33
j4976 is offline j4976
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Thanks. I will do some more checking.
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Old 12th December 2012, 11:09 PM   #34
moonmark is offline moonmark
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Join Date: Oct 2012
I, I have an AVT 50, and it keeping blowing fuses when poweramp is connected. I changed BR, fuse (6 times) and Tda7293( twice) ..so, Im checking deeply and found that on LT+ it has 32V DC but 67V AC ??? Is it normal ?? ...On LT- is -32VDC with 0v AC.... Could you help to find out if it something wrong?? Any idea to solve this issue?

Last edited by moonmark; 12th December 2012 at 11:24 PM. Reason: grammar corrections
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