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I have my lovely BM 2400 on the bench. It has been playing good for about 3 years, here the old thread.
The BM 2400 has not been used for about 6 months, Friday I connected it, it played good for about 3 minutes and then shut down totally, no bad sound, no smell, nothing, it just stopped working, no standby. Today I opened it, checking the fuses, OK, checking the voltages from the toroidal transformer I got 129 VAC in, secondary 25 VAC and 18 VAC, After the rectifier (D50) for the 15 VDC supply nothing, with the 15 VDC the RL1 should be activated and give the 25 VAC to the OD1 rectifier, the OD1 is supposed to give 31 VDC to the main feed, 18 VAC to D50 should be enough to give 15 VDC but 25 VAC to OD1 is in my opinion very low for the 31 VDC feed. Do I have a bad transformer ???
I desoldered the D50, and a diode test shows OK
Collecting Vintage B&O is not a hobby, its a lifestyle.
Hi Søren,
Have you made any progress? I'm interested in knowing how your troubleshooting goes. If I understand correctly, there is no 15v supply? If so wouldn't the standby circuit would be to blame instead of the transformer?
Last time I troubleshoot one of these, I found a completely opened resistor, without any burnt sign.
Guillaume
I changed the bridge rectifier and have the 15 V supply, but there is something else wrong, didnt have time to search further but I will be back with more in a couple of weeks, going on vacation.
If it turns out to be a transformer or perhaps the electric contact relay switch LMK - I am sure I have a spare I can send you, I dont think it is the transformer.
Ricardo: If it turns out to be a transformer or perhaps the electric contact relay switch LMK - I am sure I have a spare I can send you, I dont think it is the transformer.
Not transformer, I have 20-22 V after the rectifier, 15.8 V at TP16, "0"V at TP15, and if I remember right 15V at TP17, when I get to it again I will check the failure circuit and TR31/32
I have guests using my guestroom/workshop, and we are going on vacations for 2 weeks, will be back with more.