Denon TCD-784 (ABEX) Test CD ISO

[Nevillet]

Hi All,

I'm trying to find an ISO image of a test CD called: TCD-784 (ABEX)

I'm guessing ABEX is the manufacturer,

I'm try to repair a Denon UD-M30 which is a compact all in one CD/Amp/Tuner and the service manual calls for the above test CD.

The track listing can be found here: https://www.almedio.co.jp/wp-content...pdf?2015060501

The service manual is attached.

https://www.badcaps.net/forum/attach...1&d=1645995712

[petehall347]

Re: Test CD ISO

check this out it may do same things . https://audiophilestyle.com/ca/ca-ac...download-r780/

[R_J]

Re: Test CD ISO

What is the problem with the cd? Do you have a scope?
If the cd is working and you just want to do the alignment you can likely just use a good store bought cd, I would not use a cd image you burnt yourself.

[Nevillet]

Re: Denon TCD-784 (ABEX) Test CD ISO

Thanks both.

I've just opened the box and after the tray loads the CD it's doesn't spin up.

I've cleaned the lens with ipa but it still won't spin up.

Any thoughts?

[Nevillet]

Re: Denon TCD-784 (ABEX) Test CD ISO

The difficulty is that in order to get to the CD PCB (which lives on the underside of the drive) you have to disconnect it from the rest of the circuitry. So I'm not sure I can take measurements with the CD drive powered.

[pecrie]

Re: Denon TCD-784 (ABEX) Test CD ISO

I`m not really sure , but is there not a switch that must be activated to let the player know , that the drawer is closed ??

[R_J]

Re: Denon TCD-784 (ABEX) Test CD ISO

If you close the tray without a disc, can you see if the optics are moved to the inner part of the disc, Does the laser light? does the lens try and focus (move up & down)?
When there is a disc in the tray, does it spin freely? or is the spindle motor sticky.
If you can operate the mechanism manually (turn the sled motor gear) to move the optics to the center of the disc, then load a disc and see if the optics move to the inner part of the disc. This will check some of the operation.

There should be a tray in position switch, but if it is not working the tray usually will just eject.

[Nevillet]

Re: Denon TCD-784 (ABEX) Test CD ISO

After taking the CD deck out I can confirm that the in & out limit switches work at the appropriate time.

The motor that spins the disk does not turn on when the tray loads the CD.

The motor itself works when powered with 5V.

[Nevillet]

Re: Denon TCD-784 (ABEX) Test CD ISO

After taking the CD deck out I can confirm that the open & close limit switches work at the appropriate time.

The motor that spins the disk does not turn on when the tray loads the CD.

The motor itself works when powered with 5V.

[R_J]

Re: Denon TCD-784 (ABEX) Test CD ISO

Do not hook 5 volts to the motor with it connected to the drive board, you can damage the driver ic.
Usually the optics will focus before it spins the disc, does this happen?

[Nevillet]

Re: Denon TCD-784 (ABEX) Test CD ISO

Thanks for that.. I disconnected the motor/switch board before i powered the motor. The red/black wires were principally to measure V across the motor when in use.

[Nevillet]

Re: Denon TCD-784 (ABEX) Test CD ISO

Q: does the laser briefly switch on to check for a disk before the motor spins?

Or does the laser power on after the disk spins?

[R_J]

Re: Denon TCD-784 (ABEX) Test CD ISO

Usually the sled drives the optics to the inner stop, the laser will light, the lens will focus and the disc should spin.