2. amps-preamps
  3. 141396-109166

Filter capacitor issue

I've been a member for over 10 years and have never posted anything on here so please bear with me. My main system is a Bedini BA-802 solid state amplifier, Music Hall Maverick SACD player, Magnepan MG2.6r speakers, Denon DP-59L turntable with Micro Acoustics MA-2002e cart but I have an issue with a Marantz 2220b receiver that hopefully someone on here can help me with. I bought the receiver with plans to do some simple upgrades ie: replace some caps, etc. and resell it. I When I changed out the large filter caps I inadvertently installed the cap for the left channel backwards. I put both negative terminals on the buss bar. The right channel cap is installed with negative on the buss bar and the left channel cap should have been installed with the positive terminal on the buss bar. Needless to say the left channel cap got angry and blew it's top. After realizing my error I put in a new cap correctly but now the main 2 amp fuse is blowing after about 20 seconds. I'm thinking I may have damaged the power transistors or smaller transistors on the main amp board. The service manual also says to check the thermistors on the amp board. I'm not an electronics tech but my brother is and has been teaching me some basics over the last few months. Unfortunately he's not here to help me out this week so if anyone has any insight into this it would be much appreciated. Thanks in advance, Eddie D.
128x128skymunky57
stereo5's avatar
stereo5
6,382 posts
 
Knowing my poor diagnosing and soldering skills, I would toss it in the trash and move on.  I certainly wouldn’t buy anything you repaired as there is always a chance the unit could catch fire down the road.  If you don’t know what you are doing, you should leave it to the professionals. 
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vt4c
31 posts
 
There is no room for guesswork in electronics. If you can't explain everything in that schematic diagram find somebody else to do it.
If you don't have a schematic and better yet a sevice manual don't even try to do the surgery. Some little detail may not be obvious to the untrained eye which may cause you grief.

mrdecibel
3,063 posts
 
To the OP, obviously your brother did not teach you enough, or you did not learn enough from his teachings. The fact that you thought you can do all this work, with the intent to selling it ( probably to profit ), I am glad the piece did not go into the home of a prospective buyer of yours, as you likely would have stated to this buyer, " it was upgraded by an experienced technician ", which certainly, at this time, you are not. As far as the unit, I would wait for your brother to return, take a look at the piece, and together, determine a fix. Always....Enjoy ! MrD.
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