Arcam Delta 70.2 drive

[chlo]

Hi Mike,

Send an email to Arcam tell them you need it for repair purpose, they will send you (free of charge). I obtained one for the amplier last few weeks. I have schematic (Arcam Delta 70.2) for audio boad only.

Chlo

 

[Mike McMahon]

Chlo has been very helpful supplying some spares and advice... thanks. I still have a problem though...

1. CDM 4 motor spins continuously when powered up, even when drawer is open
2. CD's are not recognised
3. Drawer behaviour (open/close) is sometimes irratic (opens part way then closes again)

Here's what I've tried so far...

I replaced the CDM4 with a known working unit, but no change

Arcam suggested checking the 5V rails and the PSU board for cracks. All OK

Arcam also suggested checking the X1 and X2 clocks and the MAB chip on the decoder board. I don't have access to a scope, so I replaced the MAB chip (supplied by Arcam), but no change. I now have a spare chip!

As a precaution I have replaced all the electrolytics on the decoder board (except the 6.8uF one... not sure how critical this value is)

Using the service tests in the Arcam manual, the CDP goes up to service position 3 without a problem, but at 3 it holds for around 10 seconds, then reverts to position 0. This would seem to indicate that the laser is focusing fine, but the CD speed is wrong (or some other logic problem)

I could, of course, replace the 2 crystals at X1 and X2 just in case (though the value of one is a little odd)

Any more ideas?

Thanks for all your help and happy new year!

 

[Mike McMahon]

Is it OK to start this as a new post? It's gone a bit off-topic from the original

 

[Bricolo]

I don't remember who, but a member of this forum recently explained how he repaired his old cdm4 by addind (or changing) a cap at the cdm4's "head"

if Jean-Paul reads us, he may remember more as men maybe he remembers who told this

 

[Mike McMahon]

I don't remember who, but a member of this forum recently explained how he repaired his old cdm4 by addind (or changing) a cap at the cdm4's "head"

Thanks Bricolo. I have swapped out a working CDM4 assembly, including the boards associated with it, so the fault is not here.

Regards
Mike

 

[guido]

Hi,

The 7210 is probably defect. It's in my repair database from the old philips players:

disk turns constantly: 7210 defect, check pen 17 it should have a square-wave signal 0 to 5V at stop position.

One other fault with this symptom is a missing clock, but you checked that already (?).

Regards,

 

[jean-paul]

I don't remember who, but a member of this forum recently explained how he repaired his old cdm4 by addind (or changing) a cap at the cdm4's "head"

if Jean-Paul reads us, he may remember more as men maybe he remembers who told this

That was about the axial 33 uF cap that causes trouble on CDM 2.

 

[Mike McMahon]

Good evening gentlemen. Thanks for your input here...

Hi,

The 7210 is probably defect. It's in my repair database from the old philips players:

disk turns constantly: 7210 defect, check pen 17 it should have a square-wave signal 0 to 5V at stop position.

One other fault with this symptom is a missing clock, but you checked that already (?).

Regards,

I have not been able to check the clock because I don't have access to a scope. Is there any other way to check? Alternatively, which components constitute the clock and would benefit from replacement if I'm unable to check it?

If the clock is OK (or is replaced just in case) and I still have a problem, is there a source for the 7210. Is this a programmable device or a standard replacement?

That was about the axial 33 uF cap that causes trouble on CDM 2.

The working CDM4 has all new caps, including the 33uF axial.

I really do appreciate all your help

Thanks

 

[TDA1540]

saa7210 defect???

I suppose it is possible.
More likely a clockproblem(as stated above) or a problem in the motordrivecircuit.
Eitherway,you'll need a scope.

Martijn

 

[Mike McMahon]

saa7210 defect???

I suppose it is possible.
More likely a clockproblem(as stated above) or a problem in the motordrivecircuit.
Eitherway,you'll need a scope.

Martijn

Replaement crystals are cheap enough (for X1 and/or X2). Certainly cheaper than a scope. Is it worth replacing these or might the clock problem lie elsewhere?

 

[chlo]

Hi all,

For the Arcam delta 70.2, It's likely the control logic IC 74HCU04 defective?..

Regards,

Chlo

 

[Fin]

Is it needed?

Hi all,

For the Arcam delta 70.2, It's likely the control logic IC 74HCU04 defective?..

Regards,

Chlo

Hi Chlo

I'm thinking of removing this 74HCU04

If the clock is replaced (as you did) - 3 of the 6 inverters are disabled. Then if the SPDIF is disabled - another inverter and half of the 74HC74 can be disabled - which should reduce jitter. Also, I'm planning to use a Tent XO2 which has 3 outputs - one of which can replace the inverter going to the filter. That just leaves one inverter in use for BCK to the DAC. I don't think this is required - especially if WS and DATA are also reclocked.

What do you think?

 

[Mike McMahon]

Hi all,

For the Arcam delta 70.2, It's likely the control logic IC 74HCU04 defective?..

Regards,

Chlo

Thanks Chlo. RS have these in stock, but only sell in multiples of 20. Anyone got spares?

I have also moved my attention to the audio board following Chlo's comments about the chip on that board being the potential culprit. The board offers various voltage test points, inluding a +11V rail at the back of the board. This point reads arond -4v. Any thoughts?

 

[guido]

saa7210 defect???

I suppose it is possible.
More likely a clockproblem(as stated above) or a problem in the motordrivecircuit.
Eitherway,you'll need a scope.

Martijn

It is not possible, it is likely. The euras database is made up with the most found faults in the players. So it is a repair manual for dummies: e.g. if machine 'x' does 'y', replace resistor 'z'.

For a constant spinning disk-motor it is the 7210 as most found problem in more than one machine (if the disk-motor is spinning in the opposite direction, it is the motor driver's mass connection not being there btw).

Handy stuff, allthough laser worn out is not in the book.
Not the most found fault in those days

Regards,

 

[TDA1540]

CD371,CD373AH00,CD373AH01,CD471AH00,CD471AH01,CD472,CD473,CD650,CD660,CD670,CD771 or Marantz CD65DX, CD75DX. These players has CDM4/11 or CDM2

I opened up a cd473/30. It has a cdm4/19.
(the 473/00 I have,is fitted with a cdm2)