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Time to go through my stored items, the first one is my BM 4400, I did a big job on that one around 2012/13,
I took it apart changed all caps, trimmers and lamps, couldnt get it playing and had to order right and left output amps from Martin, that did it and it was playing ok and without problems, had it playing for a couple of years and remember that it had a scratchy bass poti, I changed it for my second BL 5000. At some point I took it out of store and checked it, and now it was not only a scratchy bass, now no sound from left channel, I put it back in store. Now after 4/5 years I opened it again to check what could be wrong. I connected it with antenna and speakers and found a FM station, both channels working, but after a couple of minutes I could smell and feel that something was getting hot I could feel it on the cooling fins more than hand warm. Turned it of and connected my DMM to check the idle current, around 130 mV on both channels, digital thermometer went within 5 min from 25 C to 50 C right channel more than left channel. Will continue tomorrow, I se a long haul coming up. Ideas welcome
Getting ready to clean, doing one channel to see difference, the thermal grease feel soft and not dry to the touch. I didnt find the thermal grease that Martin recommend but had to buy the one for CPUs that he doesnt like. Just to test and then change it later when I find the right one, if this is the failure
That didnt work, cleaned all properly and colocated the transistors again with new insulators and Thermal Paste in the left channel, and have the same failure. I have never had the same failure right and left, so I am a little lost where to start looking but as I never give up I will start checking from the preamps and onward
I took it apart changed all caps, trimmers and lamps, couldnt get it playing and had to order right and left output amps from Martin, that did it and it was playing ok and without problems, had it playing for a couple of years and remember that it had a scratchy bass poti, I changed it for my second BL 5000. At some point I took it out of store and checked it, and now it was not only a scratchy bass, now no sound from left channel, I put it back in store. Now after 4/5 years I opened it again to check what could be wrong. I connected it with antenna and speakers and found a FM station, both channels working, but after a couple of minutes I could smell and feel that something was getting hot I could feel it on the cooling fins more than hand warm. Turned it of and connected my DMM to check the idle current, around 130 mV on both channels, digital thermometer went within 5 min from 25 C to 50 C right channel more than left channel. Will continue tomorrow, I se a long haul coming up. Ideas welcome
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