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.
Having bought a "cheap" BS9000 MK1, because the "laser was dead", and when opening it, and seeing the original 2 PCB's having been exchanged for single PCB42, and a VAM1250 drive, including the VAM1250 laser.
Obviously it does not work, and the testmodes for lightpen in/out, does nothing. Focus on/off works.
The MK1's has a standalone connector for the clamper motor which works, including the sledge, which also moves fine.
So here is the questions.
1. Does all MK1's have 2 PCB's in the sledge, and what are the numbers on those PCB's, or are there versions with a single PCB42, and it is only the laser that has been changed in this one ?
2. Can the MK1's in anyway be upgraded to a MK3 PCB41 ? I have a PCB42 with a drive/laser that works, but obviously the connectors for the clamper motor still needs to run off the original PCB's.
Any way to get life back to a MK1 drive, without the original MK1 parts ?
/Jacob
PCB42 is a replacement PCB in combination with the newer VAM1250 laser. So your set has had a new laserunit once.
You're lucky. Just replace the VAM1250 with a new original one and you'll have a nice quiet and steady machine. Going back to the older system with a cheap Chinese laser wouldn't be my choice.
In mk1 and 2's there are mostly 2 PCB's . Sometimes there are even 3 PCB's. But the later mk2 models used to have just PCB 41 and a newer ML board, where the DAC is placed.
Beobuddy: PCB42 is a replacement PCB in combination with the newer VAM1250 laser. So your set has had a new laserunit once. You're lucky. Just replace the VAM1250 with a new original one and you'll have a nice quiet and steady machine. Going back to the older system with a cheap Chinese laser wouldn't be my choice. In mk1 and 2's there are mostly 2 PCB's . Sometimes there are even 3 PCB's. But the later mk2 models used to have just PCB 41 and a newer ML board, where the DAC is placed.
So what you are saying, is that if I fit a new VAM 1250 laser on the PCB42, and still run clamper motor from original connector, it would work again ?
What I dont understand, is why the lightpen service modes cannot move the laser ?
I have a complete set of PCB41 and VAM1250 that is known as working. Would that work in a MK1 ? I just figured that MK3 replacement was not possible on MK1 ?
Hi again.
I have a few other questions.
1. It seems that the PCB42 has been connected to the power from the clamper motor ? That does not seem right ? Why would the clamper motor power, need to be fed into the PCB42, where on the MK2 and MK3, the power goes OUT to the clamper motor ? The ground for the clamper output has been removed completely.
2. I found a loose connector, located on the ML/PL board, does anyone know where this should be connected ?
And finally, is removing of the top aluminium plate, the same on MK1's as it is on MK3's ?
Thank you.
Weebyx: What I dont understand, is why the lightpen service modes cannot move the laser ?
That's a software issue. Don't bother about it. If you instruct to move then the laser movesa little and goes back again.
Weebyx: I have a complete set of PCB41 and VAM1250 that is known as working. Would that work in a MK1 ? I just figured that MK3 replacement was not possible on MK1 ?
That's a tricky question and can vary with different setups. all depends on the used ML board.The PCB42 was specially designed to replace the original boards when a new laser (VAM1250) was placed.
Beobuddy: Weebyx: What I dont understand, is why the lightpen service modes cannot move the laser ? That's a software issue. Don't bother about it. If you instruct to move then the laser movesa little and goes back again.
Thanks. On a MK2 and MK3 I have, it moves the laser in/out like it is supposed to. On this MK1 nothing happened, but late last night, I found out that the laser-sledge motor, has some issues, it has problems getting started with a 9V battery, but if helped with a finger, it spins like it should. I will try to change that motor with another. Unfortunately I do not have another VAM1205/1250 motor, can a CDM12.4 motor maybe be used, if the spindle is changed ?
/Weebyx
Beobuddy: Weebyx: I have a complete set of PCB41 and VAM1250 that is known as working. Would that work in a MK1 ? I just figured that MK3 replacement was not possible on MK1 ? That's a tricky question and can vary with different setups. all depends on the used ML board.The PCB42 was specially designed to replace the original boards when a new laser (VAM1250) was placed.
Ok, so the PCB42 is designed to be compatible backwards to processor, and forwards to VAM1250 ?
I will try with another 1250 laser, and see if that works.
My understanding is that judging by technical notes from Philips,the CDM/Ram 12 mechs are backward's compatible,meaning that later versions can be fitted to earlier Beosound 9000's.It was alway's B&O policy to replace the entire Cd module as a service solution,rather than individual components.
It's only since their(B&O) service kits have become unavailable,that enthusiasts have attempted other solutions's
I've often seen later mech's installed and working happily,but it must be stressed that this alway's entailed replaceing the decoder/servo module with correct type also.
The laser is by far the most common cause of failure with any of these otherwise reliable machines.
Now that new good quality lasers are available again,it's getting easier to keep these systems functioning.
A specialist in the uk can supply the correct laser.
Contact AV services of Exeter(good website too)for more info.
I have no commercial connection with this company,other than as a satisfied customer.
Good luck with the repair.
Nick
So, last night, I got the unit working again, seems that the MK1 with a PCB42 replacement board, and a VAM1250 laser is compatible.
I just wonder if the PCB41 board that comes as replacement for the PCB40, also works ? Could it do any harm just trying ?