ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hello everybody,
I'm new to this forum. I recently got my hands on a BM4000 from my grandma. The left speaker output had died. I replaced the big capacitors next to the big transformator but when i switched it back on, it made a popping sound from the right speaker and started smoking on the opposite side of the replacement. It still turns on (light is on) but no sound at all, not even a hum. This in FM mode. The fuses seem alright.
I've read about replacing all the capacitors and resistors on the board? But this seems quite an enterprise.
What is your opinion on this?
Greetings.
was there any particular reason for replacing the big capacitors (leaking perhaps?) or was it just a random choice? whatever the reason it sounds like you have made the situation worse......replacing all the capacitors is unlikely to resolve the issue. You will need to repair the unit first, which will involve tracing the fault you have introduced and then the original fault on the left chanel. Both exercises require a modicum of electronics knowledge and some test equipment.....there are a number of threads here that may help you decide if its something you can undertake yourself.....good luck
Regards Craig
Yes the capacitors (5000µF 75V) were bulging and leaking so I replaced them with 4700 µF 100V (easier to come by and cheaper). I'll take a look. Thank you for putting me on the way.
Whatever the fault has probably resulted in one or two components that are now shot. Power comes on but the fault in the amplifier circuit causes the Beomaster fault detection to keep the amplifier circuit shut down. It probably did (does) need a recapping but it sounds like some other fault was present or introduced. It also sounds like the fault is in the left channel. Recapping these low profile receivers can sound simple but it isn't if someone is not familiar with them. The board components are very close together and the main board does not easily come out to get to everything. I would check solder connections on the board too. Did you have the unit open when the fault occurred? If so do you know where it was on the board? Can you see any burned areas on the board? They can help show the are to start looking.