Bang and Olufsen Icepower 500asp module sch

[Misley]

Did someone manage to find service manual or just sch for mentioned power amplifier module?

[Jazz P Bass]

Nope.

Unobtainium!

The manufacturer will not release it.

[J M Fahey]

I bet the service manual has just 1 line:
"Get a new one"

and I´m only half kidding

[Misley]

[A lot of bad words here]

Thanks guys. At least, I have another working board for inspection and compare. But,the time is not working for me.

[J M Fahey]

About Ice Power not releasing schematics, Fender who usually do , in an amp where they DO use one of them, they show the full schematic of *everything* ... except the built-in Ice Power module, which they treat exactly the same as if it were, say, a TDA2050 or LM3886 IC .... as in: "you really won´t think about opening and repairing one, will you? .... they are straight replaced !!!!!"
FWIW; I know of people who open sealed Sanken hybrid power IC modules and replace dead parts inside, so ......
look at:
Fender Rumble_150_2010_schematic_Rev-B.pdf
obviously such module is not intended to be repaired, period.

At he same time, besides a power amp, it´s also the power supply to everything, line cable goes straight to it, so if it does not work, nothing else does, not even the preamp .
Oh well, as disposable as:

[MarkusBass]

You haven't mention what exactly problem you have with the module. I fixed several B&O modules (without the schematic) but they all had problems with the power supply. I think I was lucky to fix them.

Mark

[martinmur]

Well, the most common problems are related with Power Mosfets at the audio output . Did you check if you have the auxiliary voltages at the P1 and P2 connector? you should measure +80V, +50V and +/- 12 volts. If you have those voltages present at P1 , probably your issues are related with Output Mosfets 75639P, for sure broken, just replace the 4 mosfets and that's it. Module will work again. The most difficult problem with this module is the power supply , Ice power uses an UCC3808-1 PWM chip in a very very strange configuration, The current sensing reference is taken from a small transformer T201 ( instead of the proper switching mosfets) it feeds the voltage to a very small fast recovery diodes A7W (normally broken when the problem occurs at the same time a resistor of 2.2K is also broken or burnt) this signal or voltage goes directly to the pin number 4 (CS) of the UCC3808-1 , I do not understand clearly what for or why the use it in this way, Sometimes if you remove those diodes and the resistor, the module works again, obviously without the current protection. If you attempt to fix the power supply to replace the parts for original ones should be necessary otherwise the current sensing will protect the power supply even the parts you already replaced are in good conditions and brand new but similar and not original. To be honest those modules are a real nightmare when fails.

[glebert]

Well, the most common problems are related with Power Mosfets at the audio output . Did you check if you have the auxiliary voltages at the P1 and P2 connector? you should measure +80V, +50V and +/- 12 volts. If you have those voltages present at P1 , probably your issues are related with Output Mosfets 75639P, for sure broken, just replace the 4 mosfets and that's it. Module will work again. The most difficult problem with this module is the power supply , Ice power uses an UCC3808-1 PWM chip in a very very strange configuration, The current sensing reference is taken from a small transformer T201 ( instead of the proper switching mosfets) it feeds the voltage to a very small fast recovery diodes A7W (normally broken when the problem occurs at the same time a resistor of 2.2K is also broken or burnt) this signal or voltage goes directly to the pin number 4 (CS) of the UCC3808-1 , I do not understand clearly what for or why the use it in this way, Sometimes if you remove those diodes and the resistor, the module works again, obviously without the current protection. If you attempt to fix the power supply to replace the parts for original ones should be necessary otherwise the current sensing will protect the power supply even the parts you already replaced are in good conditions and brand new but similar and not original. To be honest those modules are a real nightmare when fails.

This thread is over six years old, but welcome to MEF!

[Jazz P Bass]

Agreed.
What a good post.
Thanks.

[Rup]

Well, the most common problems are related with Power Mosfets at the audio output . Did you check if you have the auxiliary voltages at the P1 and P2 connector? you should measure +80V, +50V and +/- 12 volts. If you have those voltages present at P1 , probably your issues are related with Output Mosfets 75639P, for sure broken, just replace the 4 mosfets and that's it. Module will work again. The most difficult problem with this module is the power supply , Ice power uses an UCC3808-1 PWM chip in a very very strange configuration, The current sensing reference is taken from a small transformer T201 ( instead of the proper switching mosfets) it feeds the voltage to a very small fast recovery diodes A7W (normally broken when the problem occurs at the same time a resistor of 2.2K is also broken or burnt) this signal or voltage goes directly to the pin number 4 (CS) of the UCC3808-1 , I do not understand clearly what for or why the use it in this way, Sometimes if you remove those diodes and the resistor, the module works again, obviously without the current protection. If you attempt to fix the power supply to replace the parts for original ones should be necessary otherwise the current sensing will protect the power supply even the parts you already replaced are in good conditions and brand new but similar and not original. To be honest those modules are a real nightmare when fails.

Amazing piece of information !

I am currently trying to fix a 500asp from a B&W ASW610XP subwoofer, maybe you might have an idea of what could be the weird failure I have !
Mine stopped working suddendly. One day it simply did not turned on...
I measured the power section not to work (no +12/50/80V). However, no component seemed burnt anywhere, and the module looks perfect. But most of the time the power does not start.
I tested the electrolytics capacitors on the power section, since they would be the usual suspects, but they are all within specs.
As suggested, I tried the option of removing the 2x A7W diodes and the resistor and this made the module power up, but only temporarily !!! After a second power up 2h later, no more power. So I placed back the component, module worked again a few times. Hurray ! ...
But 2h hours laters power gone again...
Lol.. very weird isssue
I though about "cold" joints since moving//heating the board seemed to have some effect, but obtained again on/off results after reflowing quite alot of joints.


Anyway, if anybody has a lead, I'll take it !
And I definately concur, those modules are real nighmare to repair
I hope it's an isolated case since this does not show very good reliability for these board...