Was the problem present before you started work?

They usually dont go out of alignment by themselves.
Either someone messed with the alignment or something has gone wrong in the tuner frontend or IF stages.
You could check the voltages and signals around IC TBA460 - though this IC rarely fails.
It's less unusual to see the frontend FET go weak. Tim wrote about it at some point on Beocentral and suggested
a replacement FET and some modifications, but it may be a lot easier to simply replace the complete frontend module with a
known good used original module than attempting repairs and aligninment to the defective module.

Martin

Thanks for reply Martin ,
yes the unit was stocked for years and I lit a week ago .
Just noise and very far station .
Alignment is still original , no one seem mess with adjustment 
but some trimmer are very scrapped .
Voltage around the tba460 are around 20% lower than on schematic (fm mode no bracket value ) but no fm signal on input , just dipole .
Today I spent some time and start replacement with new pot for R9 (I've read the value on PCB for near value position)
And some elko around front end / decoder ; the orange caps .
They seem fine and esr & cap are ok.
turn on , now I've tuned some station , great improvement .
I don't think that the replacement  all tant caps around will go better . Anyway the fault seem caused from component deterioration .
In green part replaced for tuner ; in red still in progress AF pcb

Play a cd from input sound fine .

system down ,, I can post picture ..will try later 

many thanks

Login to view image

I suggest you replace those Ducati capacitors. Ten in total.
They may not be the reason for the fault in question, but they will cause problems - sooner rather than later.

The three large electrolytic cans are not original but may be fine.

Check the power supply voltage adjustment. It can cause strange problems if far off.

Martin

The not original parts  (in red on picture  ) has been changed by me few hours ago .

But now  It's frozeen in garage 

The unit was original ; go for ducati .

I can not find replica of antenna wire connector  , with 2 spade . I have lot a receiver but got only one .

When will change all others parts will be check bias again  I give feedback

Gabriele

ciao ,

After a  healthy recap things get better station are stronger but no way to light stereo lamp .

 Great improvement has been reached when test some resistor in fm path .

Some resistor measure 50% off value , they are most 1/2W carbon ; now the receiver get FM STEREO station🙂

Now I'm getting into restore a BM4400 !

some resistor :

[View:https://imgur.com/a/jd89mLt:800:0]

https://imgur.com/a/jd89mLt

Hi ,

Thanks for your thread who helps me,  i have similar problem, (weak FM) and for me it's the TR1 in FM section (MPF120) who is dead

you can see my topic /forum/imported-unmapped/beomaster-901-tr1-in-fm-mpf120#post-2213838