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
Here I am with another BM1900(problem).
A few years ago I had put aside this one waiting for some courage to open it up and try to solve a noise effect. Speakers not connected, the standby led lights up, it allows me to select input sources, the respective lamps light also up, however, when speakers connected: same behaviour, ccompanied by the volume at maximum level, which cannot been brought back to normal. The volume level control has no effect.
It is hard to search for the culprit inside while the walls of my room almost are torn down by this deafening noise.
How can I bring back soft music to the connected speakers?
Aad
Does the volume lights indicate max volume when it happens?Has the lamp inside the LDR casing burned and the monitoring circuit gone bad?
Martin
Answer to your first question : yes.
I will check the LDR casing tomorrow.
Please show me the way to the monitoring circuit, what parts do this circuit comprise, where is it located?
It's the small circuit "feeling" the current flow of the lamp inside the LDR housing, activating the mute function if the lamp burns.A burned lamp would otherwise cause max volume. - But not max readout. Hence my question.So your problem is not the lamp or the monitoring circuit.Did you replace capacitors on the volume control board?Check for vertically mounted components inadvertently touching eachother.And check for cracked solder joints, particularly where wires are soldered in to the board.
Check also the solder joints on the small fuse/relay board. Especially where the heavy guage leads from the transformer etc. are fitted.
And check that no shorts are present where the large pin connector to the tonecontrol board is fitted (the tonecontrol board also carries the volume preset switch).The pin connector has some wires, that can sometimes touch joints at the solder side of the board and even eachother.
This will keep me busy for quite some time during a possible new lockdown over here.
Thank yoU