Pascal x-Pro Modul clipping with 4V output

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Hello I own a Pascal X-Pro1 modul which is limiting the speaker output to 4V.
If i try to get more out of it , I get a clipping signal at the output.
Up to 4 V Output voltage raises normaly, than the clipping led starts to light an the sine wave on the output gets deformed.

I have a second one which is working properly in the same Setup.

I have checked the four transistors of the output stage and checked the +90V -90V rail, also checked the +15 -15V , everything seems to be ok.

Does anyone have any Idea where else i can search for a defect?

Does any one have a schematic for the modul?
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I used an 8R Load.
The X-Pro1 only has the 2500W Output, this should be a bridged Output.
Grounded only through the main plug wiring.
Atached the pics from the good and the bad modul.
Both at the exact same Setup, only the signal-input voltage of the second one was reduced.


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If you have two, one working, one not, you can walk trough the whole cirquit until you find differences. This is how repair technicians have been working for the last thousand years.

While repair in ancient times was always an option, today one must accept that most stuff is NOT made for any repair. Check fuse, if still not work, throw away, done.
Yeah,, I know about that option, but it takes a lot of time because I have no clue where to start the search.
Electronics isn´t my favourite.
I know how to use the measurement tools, but walking through whole the circuit will be a pain for me, I know only a little about class D designs.

Fuse checked ;)
Will probably end with throw away.
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Emailed them, but no support from them for customers, only for oem buyng big numbers. :(

Yeah, more or less the same response I got, except I had a very different question.

Have you checked if there is something wrong with the "Amplifier Output Voltage readout" or "Amplifier Clip readout" pins?
Something wrong with these might cause "Dis_Read/Protect– This readout is an open-collector output which will be pulled low when the module is either muted or has entered an internal protection." In which case you can measure it and figure out the general part of the board where the problem is.

Other than that I'm not much help.

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