Ok I need to pick the brains of the technicians in this group. Maybe someone will have a clue, cause I sure don't! lol ... I have a CD player (B&O CDX) that once turned on, has to sit for 5 - 10 mins before it can be played. The strange thing, is how it tells you when its ready to be played. I press power, don't touch anything else and just let it sit .. 5 or so mins later, it will emit a loud static out of the speakers, which will then slowly taper off over about a minute. After this, I can play the CD no problem (with a bit of static here and there). If I try to play a CD before that, it will just sound distorted until that same 5 or so minutes passes, then the sound clears. Anyone have a clue?
Things that have recently been done to this player, so can be ruled out as the cause are:
-Griplets fixed (common philips CD 104 issues)
-solder touch ups
-RCA cables replaced
-lens cleaned
-voltage regulators replaced
-reed switches replaced
-OP-AMPs replaced with TI LME49720
-electrolytic caps replaced on pre.ampl. & Laser PCB
-electrolytic caps replaced on motor board - PCB disc motor stop
-electrolytic caps replaced on decoder board
-electrolytic caps replaced on power supply board
-electrolytic caps replaced on servo board
Things that have recently been done to this player, so can be ruled out as the cause are:
-Griplets fixed (common philips CD 104 issues)
-solder touch ups
-RCA cables replaced
-lens cleaned
-voltage regulators replaced
-reed switches replaced
-OP-AMPs replaced with TI LME49720
-electrolytic caps replaced on pre.ampl. & Laser PCB
-electrolytic caps replaced on motor board - PCB disc motor stop
-electrolytic caps replaced on decoder board
-electrolytic caps replaced on power supply board
-electrolytic caps replaced on servo board
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Could be many things tbh.
It might be worth trying judicious use of freezer spray on some of the chips to see if that brings the noise back once it is playing. Cheap cans of air duster (butane based) make a decent alternative. Invert the can and practice dispensing it drop by drop.
An oscilloscope is pretty much mandatory for all fault finding on things like this... you need to look at rails and so on for correct values and noise/ripple.
It might be worth trying judicious use of freezer spray on some of the chips to see if that brings the noise back once it is playing. Cheap cans of air duster (butane based) make a decent alternative. Invert the can and practice dispensing it drop by drop.
An oscilloscope is pretty much mandatory for all fault finding on things like this... you need to look at rails and so on for correct values and noise/ripple.
Thanks for the reply Mooly. Due to the way this player is built (top loader needing the top half of the chassis in place to clamp the disc.. among other things), Its near impossible for me to run it while having access to the servo board to freeze spray it, however, I may be able to get to the decoder board while it is playing, I will try this as tricky as it might be. Also, I don't have an oscilloscope so I guess the point for my post is that I am hoping someone has already run into this issue before and was able to diagnose and correct it and share their thoughts.
Thanks, I will check into the RAM chip, too bad it will be so hard to find one if I need to replace it.
Id check every voltage with voltimeter since you power up until it gets operating, +5, -5, +12, -12, etc...
Bang Olufsen uses Roederstein capacitors. My opinion about Roederstein capacitors is bad, very bad. The logo of this brand is ROE. I change this capacitors every time I see them.
Don't confie in Ebay or Aliexpress components, like Op-amps, power regulators. I'd not change any component until I were sure it is bad.
Well, like i said in the begining, the most important, check all voltages in power supply, looking any variation.
Bang Olufsen uses Roederstein capacitors. My opinion about Roederstein capacitors is bad, very bad. The logo of this brand is ROE. I change this capacitors every time I see them.
Don't confie in Ebay or Aliexpress components, like Op-amps, power regulators. I'd not change any component until I were sure it is bad.
Well, like i said in the begining, the most important, check all voltages in power supply, looking any variation.
The ROE caps have been replaced with Nichicon, not from ebay. I buy all my parts from authorized dealers.
Thanks for that. I have been trying to source a RAM chip as others have also suggested I replace it, but seems impossible to find from my usual sources. Do you have any reliable sources for OKI ram chips that ship to Canada?
Unfortunately that is just as hard to find, and much more costly as people know that the Philips CD 104/CD 104 based is highly collected. I do look for them on a regular basis and even non working ones are $300+. I did find the chip in a couple places for $5, however, with shipping it quickly became $35 lol .... I guess this one is going to take a while.
Looks like I found a modern day substitute for my old OKI ram chip. I will confirm next week and if its a go, I will report back my results!
fingers crossed then 
It had to be tried
I'd probably go down the route of using freezer spray (very sparingly) now.
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