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Flea and other mods to CDi...

Cough - thanks Martin, OK, I've read again and think I understand this time :) I'll bodge a 317 with a second 317 tpr onto veroboard for the 7220 reg - if nothing else it will help with excess of volts I will have!

I work on a full parts list in next day or so - any recommendations on what red and green LEDs to order for testing? I normally use Farnell, but will also be ordering a host of mounting hardware from eBay seller Mike linked to earlier, so multiple suppliers ok.

Thanks again for everyone's assistance - I love this place :)

Richard
 
Actually Martin - was the CD2 7220 supply dedicated for that chip, or shared? I need to map out the 317 type regulator strategy in my CDi - there's 10-15 of the little buggers in there...and Naim didn't do a bad job in stock form on these early players either! Maybe I could modify the onboard 317s and feed them with a dedicated raw supply?
 
The CD2 uses one 317 as a pre-reg feeding a couple of rails, after which there are two 317s feeding (1)5v only to teh 7220 and (2) an lm317 feeding 5v to teh microprovessor.

Easiest fix is to wrap the prime reg around the 317 to the 7220 as a tracking prereg arrangement. The lm317 feeding the microprocessor can than hang off it, or (as I did) just be fed from the raw rail - it only draws mA. Bonuse onts add a little RC filtering beween teh raw DC rail and teh tracking preger - 2.2R/100uF or so - huge benefit in knocking-down the kind of HF/rectifier noise that passes straight through the regs for only half a volt or so of lost overhead.

These days I used a completely transmogrified fleaboard (onboard T0220 output transistor, plus separate regulated 12v supply for error amp) as the reg for the '7220, with the output stage all inside the f/back loop using that original 317 as a tracking pre-reg as above. Blinding performance, but requires a little finesse - not a beginner's recommendation!
 
Damn - listening for first time in few days tonight (man-flu, hearing shot) - half way through disc sound stops and get an ERR on display. TOC still there from before, try and play again and ERR. Try and re-read TOC and no go, but no ERR either.

Need to pull it apart and see what I have screwed up!
 
Sadly our creations often take a step backwards out of spite, mine do anyway so your not alone.
 
As far as I can tell, the failure is not related to the fitting of the flea. I'm going to open a separate thread to fault find - just replaced the 3 electrolytics to no avail :(

Richard
 
If the clock signal goes AWOL, the norm is for transports to runaway and spool-up to quite high rpm (because the disc servo has no reference) - you'd know about it.

Do check for dodgy solder joints on any changes you have made.
To read (or rather, re-read) the TOC, the laser has to find focus first.
To do that, laser swingarm/sled has to be in right range of start position.

Good hunting!
 
Thanks Martin - yes, to confirm; swing arm heads to inner of disc, laser emits red light and tries to focus with no disc mounted. However, spin motor just pulses as per this dropbox link.

I don't really believe in coincidences, so will also strip out main PCB and check everything tomorrow - probably also connect scope to crystal output - but there is only the 2 wires i mounted for TDA crystal feed, plus the one pin of the 7220 I lifted - everything else I did is external...and Flea's green LED is still happily shining :)

Richard
 
The disk motor will not spin if the controller cannot see the disk for whatever reason. The normal sequence of events is to position to index track, attempt focus on the disk and then spin the disk to lock on and read it. The laser may be working but the the photodiodes may not be seeing the reflected pattern properly.
 
Thanks - yes, did some reading up today. It's the CDM9 Pro based model - so focus and then spin I think. With no disc the arm moves to Centre and attempts focus (laser light there, lens moves up and down) - I haven't tried with something shiny yet to see if it tracks it.

With a disc though, the spin motor just pulses the 3 times, with that worrying flashing of display and stop/play LEDs.

There was zero warning of the fault - half way through a CD sound simply stopped, I looked up and display showed err and returned to TOC.

I've got a Marantz cd23 service manual, also cdm9 pro based, which I hope uses the same servo chipset (why didn't I take a photo of the surface mount chips while I had it in bits last night...), tda 8808 & 8809 I hope.

Guess I dust off my scope and check the clock is all OK first, and then check under main PCB to ensure I didn't screw anything up when fitting flea - but this is a PITA player to have full access to, and to be able to run it. Can see me making some extension looms.
 
That all sounds completely normal for a Philips Laser based player that can't read the disks whether it's a swing arm or linear meachanism. It sounds like you'll need a new laser. The heads are transplantable between CDM9 and the Pro models.
 
Thanks - although it's had a lot of use, I already transplanted the laser from a 9/44 into it 8 or 9 years ago. Maybe it has failed again (although when I bought it faulty symptom was spin motor would take off at high revs while trying to read TOC), and I'm keeping an eye out for suitable donors anyhow, as at some point I will need to rule it out.

Thanks again, Richard
 
Richard - if its a CDM9 have you checked the turntable height? They can just slip down the motor shaft with heavy use (repeatedly dropping the puck on!) and that interferes with focus. Had exactly what you describe before with my CD2; the turntable is a simple push- fit and easily tweaked.

LesW long ago posted for the arcam alpha 5 a good description:
Taking a couple of thin bladed knives, insert one under each edge of the platter and gently twist them both at the same time a 'click' should be heard. This generally signifies that the platter has been restored to it's detent position on the motor shaft and should turn with very little resistance when coaxed by a finger. Should the above procedure overdo the the lifting operation, insert a piece of cigarette packet or preferably a 25 thou (Imperial) feeler gauge under each edge and gently push down on the platter. It should now have settled in the correct relationship with the motor shaft and should now play as God intended.

Similar problems encountered with the CD3 may be tackled in the same way but I counsel that the feeler gauge procedure will be preferable to guesswork as to where the platter should rest.
Click to expand...

Practically translated to the Naim 'tray' use, I find you should be able to just fit two business cards between turntable skirt and the metal of the mech below - it's the right ballpark.


ETA just measured one of my cards; 0.35mm = 13thou! happenstance, or design? hmm...
 
Thanks Martin - I haven't checked it...but will :)

I bought my CDI faulty originally, and someone had tried to prise the original metal platter off, warping it badly. So mine has the plastic 9/44 platter on it it - redrilled and remounted. It did slip down once, when my ex-wife had access to the player and was a bit bit "clumsy" placing a disc on the platter, but that was a good clout that made it obvious. Maybe this time it has slipped just a little...I check.

Damn - 9/44 mechs got expensive! Grandata had them for £24 back when I repaired mine (but I ended up getting a known good one from Les for a bit more)...Grandata want £180 now! I should have stock piled :)

Richard
 
MJS said:
There's one going on Ebay right now. No bids, runs until 10/2.
http://rover.ebay.com/rover/1/710-5...0001&campid=5338728743&icep_item=262274322819
Click to expand...

Thanks Mark - unfortunately he had it for sale to uk only. I contacted him and he opened it for EU just before boarding a flight back to UK from US...but Switzerland is not part of EU formally (from a tax perspective :))...so I still can't bid on it.

Anyone fancy buying it for me,I'll pay a finders fee if it stays below £60? :)

I checked the platter height tonight, it's fine and still stuck fast in position after my last repair to it a few years back.

Richard
 
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Thanks - no worries, I'm patient...and don't even know for sure it is the laser yet. I need to get my proper fault finding head on with a scope and spend some proper time on it - not going to happen for 2 weeks...

Richard
 
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