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
Hi All,
I have an Overture that has been in storage for a while and appears to have developed a fault. When switched on it works perfectly for a minute or two, then the display starts to dim from normal brightness to off over the course of around 10 seconds, and at the same time, mains frequency noise starts and builds in intensity until it is very loud (tested only using the headphone output at this stage)
The CD also stops spinning at this point (if it was playing beforehand) - but the problem does occur regardless of the source in use at the time.
The glass doors will still open and close, as will the clamper, and it sounds like the volume and source buttons are still functioning, as well as the standby light flashing on each button press as usual, so I suspect the microprocessor is still functioning throughout.
Given the unit will again operate normally for a few minutes once it has been powered off for a while (presumably once any residual charge in the capacitors has leaked away, although I suppose it is also possible it is once the faulty component has cooled) I'm suspecting a faulty capacitor in the power supply circuit, and having examined the schematics, my suspicion is that the fault lies somewhere in the -15V section of the power supply, as this is common to the affected components but not to the parts of the device that appear to continue to function throughout.
I am away from home at present so don't have access to the overture, which means I'm unable to diagnose further at this stage aside from studying the schematics for clues but wondered if anyone had encountered a similar issue? knows of any common faults I should look for? or could offer any further pointers so I'm as prepared as I can be to diagnose further once I'm back at home?
Kind Regards
Martin.
Ok, I'm working locally again now so back at home and have managed to find a little time to start investigating the issue further. It does appear I was correct in my assumption that it is a fault with the -15V line, but I have yet to determine the exact cause.
Does anyone here have access to an original copy of the Ouverture service manual. I could really do with a higher quality scan of the PCB component layout drawing for PCB12 (page 2.12) as it is impossible to read some of the component labels in the pdf copy on beoworld.
This ouverture also has an 8k2 resistor that has been soldered across (in parallel with) R181 - I'm not sure if this was some B&O recommended modification made at some stage or a poor solution / workaround to a previous fault.