Finally, an affordable CD Transport: the Shigaclone story

[Ed LaFontaine]

JC Fardo posted: About the O rings honestly I cant´t figure how they go with springs assembly

Good Morning form here

Take a look at Peter's post #868 & 869:

Peter's photo of Levinson

Don't look for a specific example of this in the thread...we are building this in my head for now...

Where Peter has used the mass of metal to load the springs in his suspension, I am suggesting the use of "tensioners". The tension springs in post 869 are an example of this.

The o-rings are used as tensioners. An o-ring is hooked onto a point of attachment on the plinth and then stretched gently to another point on the sub-base. This tension compresses the springs slightly. Each additional o-ring increases the compression of the springs. The compression of the springs is balanced against the tension in the o-rings along with the weight of the plinth.
I think I'll start with 2 o-rings on all 4 sides of the plinth, 1 on each side of a corner, 8 o-rings.

[spacemen12]

Hi all,
I don't know if I imagine all this or if it is real. I have the pdf document of Okapi and there is no type of cap for the transport board. I think I saw somewere a list of component with the type of all caps, not just the PSU. Can someone point me to the document/post, I cannot find it,

Thanks

[kevinkr]

Originally posted by quan
Thanks Kevin for the reply,
i have tried to connect the PS thru C952 which meant to removed anyway from RC-EZ31.
The problem is that- no power onto the transport board, the C902 which i think is a voltage regulator gets very hot and then smoke. It is not the cap that smoke.
The other thing that i noted as well that the transformer from the power supply start to hum or oscillate?.
Where should i check next?.

Hi Quan,
I think you have mis-identified C902, it is a cap associated the ASP chip. Did you connect the power up backwards by some chance? If any chip smoked it is likely you will need to look for another boom box. You might be able to find replacements but I don't know how likely that is.

[kevinkr]

Hi Quan,
I hope you did not mean IC902 because if that is the chip that smoked it is a clear indication that you made a serious wiring error and this board set is history unless you can get all of the chips IC901, 902, and 903 and identify all of the many other components that will need to be replaced as well. (The laser and photo diodes may also be damaged - so I would replace the whole thing.)

The fact that the power transformer buzzes loudly when connected is a strong indication that something has shorted out.

Do you have a meter? Can you measure the 8V supply, after carefully rechecking everything.. Incidentally I recommend soldering the wires on the bottom side of the pcb at C952. I don't recommed drilling any holes out as no one (myself included) other than Peter seems to be very adept at this.

Sorry to be a bearer of bad news, but this does not sound good.

FWIW I toasted the first micro-controller board in my RCEZ32 based version so I know what angst you must be feeling right now. Purchasing another one of these rather rare boom boxes was the only option in my case.

[hayenc]

Having applied too high voltage to the transport myself, I might offer a small glimmer of hope. Kevin is right in that if the voltage was applied backwards, there might not be hope. But I applied about 14 volts and the 10 v electrolyitc went, and the supply itself went (or was already bad), but the rest of the transport survived. The motor driver chip is rated about 14 volts with internal regulator. The rest of the chips on the 32 have regulators in front of them. Now those transistors may be fried, but the chips themselves may have survived.

Since you have a 31 and the service manual has been posted, it would be worth checking against the regulation in the schematic before tossing the transport to see if only the regulation was damaged.

But I do agree with Kevin. First step is to ensure you have a properly functioning power supply indepedent of the transport. I was able to fit short power wires into the holes that used to hold the inductor, but checked way too many times to ensure I did not hook them up backwards.

Good luck in your trials.

Craig

[Richard]

Hi Franz,

Because we have a long weekend, I decided to take a Studer D730 at home to do comparisons with my Shigaclone.

I'm curious to your findings. It seems that the Studer is using a CDM 4 variant.


I haven't had time to do any further mods to my JVC. Just some of my findings regarding the puck/clamp:

When playing with the Philips transports a friend and I found that the mass of the CD puck has an effect on the sound, we used blu-tac and washers to experiment, finding that the optimum mass was about 40 grams . I had an engineer machine a brass disc to about 42 grams which I glued to the original Philips clamp (lead mass removed). It worked well, the most important thing was that everything was correctly centred, this drastically reduced any vibrations.

I haven't implemented anything like this on the JVC yet, but lowering the centre of gravity of the clamp/puck may also be of benefit.

Happy modding

Richard

[luvdunhill]

I have a small trace that is popping up. Any recommendations on something to "glue" it back to the board?

Also, FWIW I have had luck enlarging the holes using a 1/16" bit placed into a tapping chuck and then using it by hand. I've enlarged a number of holes on this board using this trick. I'm still not confident enough to try and accesss the DOUT pin directly though.

[Pendergast]

Originally posted by luvdunhill
I have a small trace that is popping up. Any recommendations on something to "glue" it back to the board?

Also, FWIW I have had luck enlarging the holes using a 1/16" bit placed into a tapping chuck and then using it by hand. I've enlarged a number of holes on this board using this trick. I'm still not confident enough to try and accesss the DOUT pin directly though.

luvdunhill,

One trick I use in such circumstance is this:

1) get a magnifying glass from a watchman/clockman repair guy
2) get good lighting conditions
3) use a sewing needle
4) scratch delicately until you reach the metal

Alternatively, get the schematics, find where the line goes to the next submerging trace, then solder your component's other leg there.

I had that unpleasant experience several times, but managed to get by. If you have a component leg extending over a lot of other exposed components, use some isolation tubing to cover and isolate that leg. Very cheap stuff and always useful.

Hope this helps!

[JonHarrison]

I have a small trace that is popping up. Any recommendations on something to "glue" it back to the board?

Try a small amount of super glue.

[luvdunhill]

Originally posted by JonHarrison


Try a small amount of super glue.

Hey Jon!

yup, this is what I've done in the past... seemed kinda ghetto though...