Flea and other mods to CDi...
- Thread starter Dowser
- Start date
Dowser
Learning to bodge again..
Thanks, no - I was listening to it when it failed, mid track it just stopped playing.
Things to do;
- there are 2 low value tants around the 7310 - I try swapping them over
- 2 other very small tants, one used in CPU cct, one on servo board - swap them around
- trace laser RF signal through the chain from tda8808 (what I should have been doing yesterday
)
However, I need some time off from damned thing
Things to do;
- there are 2 low value tants around the 7310 - I try swapping them over
- 2 other very small tants, one used in CPU cct, one on servo board - swap them around
- trace laser RF signal through the chain from tda8808 (what I should have been doing yesterday
)However, I need some time off from damned thing
Dowser
Learning to bodge again..
Dragging this back up from the dead - a year and four months later I decide to attempt repair again. I recently bought Laverda's heavily modified CDi - it had a fault (white noise at output), but read discs. I figured I could track the fault on mine down using his, and vice versa.
Laverda's CDi *did* read discs - I stupidly stopped the disc motor manually by hand while it was playing a disc - it did not like this at all (but I am sure I did same to my CDi on occasion too without harm),and disc now spins slowly backwards constantly! What an idiot
So, I then started swapping bits to see what effect they had - one with disc running slowly backwards (Laverda's), the other with 2 or 3 little blips of spin motor and no more (mine) - neither reading TOC;
1.) I put my servo/laser in Laverda's - weird, same slowly running backwards, but now also with those 2 or little blips that mine experienced. Conclusion - problem with mine is with servo/laser.
2.) Laverda's servo/laser into my machine - no more backward spinning, disc spins correctly but fails to load TOC (you can hear laser trying to focus)
3.) I then check platter height on Laverda's mech - it looks a little low - sure enough, trying to prise it up shows the glue bond had broken. But resetting to 25 thou between bottom of platter and mech chassis made no difference - still spins up correctly, you can hear laser trying, but fails with ERR
4.) Then I try my laser on Laverda's servo - fault as per mine returns; 2 or 3 little blips instead of attempting TOC. Conclusion: something wrong with my mech
5.) Laverda's laser on my servo - disc only tries to spin clockwise when lid open! Conclusion: something wrong with my servo too!
6.) I then swapped the laser assembly from a working cdm9/44 in a Kodak PC860 into Laverda's mech - same issue - spins but no TOC, just ERR. Putting Laverda's laser ass back into the Kodak and it works fine.
7.) I noticed that on my player, the MN4264P-15 (DRAM chip) runs very hot, maybe hotter than the SAA7220. I later checked on Laverda's - it is warm but not hot on his. Need to check this point further.
8.) I put my machine away at this point, and went back to Laverda's - putting his servo/laser back into his machine. Same: disc running slowly backwards. Flea output looks OK scope, but to be sure I pulled the Flea out of my Marantz CD60 to confirm - still same.
9.) I then swapped the SAA7220 from the CD60 into Laverda's - still the same, disc running slowly backwards.
I now give up for the day While removing parts from the CD60 I see it uses the same chipset as the Naim, so will study it's circuit in more detail tomorrow.
At this stage I suspect I have separate faults on my laser and servo, and that Laverda's has a problem on the main board somewhere.
Has anyone ever had a SAA7310 fail? This is where the clock from pin 9 of SAA7220 goes to. And disc spinning backwards suggests clock fault?
Cheers, Richard
Laverda's CDi *did* read discs - I stupidly stopped the disc motor manually by hand while it was playing a disc - it did not like this at all (but I am sure I did same to my CDi on occasion too without harm),and disc now spins slowly backwards constantly! What an idiot
So, I then started swapping bits to see what effect they had - one with disc running slowly backwards (Laverda's), the other with 2 or 3 little blips of spin motor and no more (mine) - neither reading TOC;
1.) I put my servo/laser in Laverda's - weird, same slowly running backwards, but now also with those 2 or little blips that mine experienced. Conclusion - problem with mine is with servo/laser.
2.) Laverda's servo/laser into my machine - no more backward spinning, disc spins correctly but fails to load TOC (you can hear laser trying to focus)
3.) I then check platter height on Laverda's mech - it looks a little low - sure enough, trying to prise it up shows the glue bond had broken. But resetting to 25 thou between bottom of platter and mech chassis made no difference - still spins up correctly, you can hear laser trying, but fails with ERR
4.) Then I try my laser on Laverda's servo - fault as per mine returns; 2 or 3 little blips instead of attempting TOC. Conclusion: something wrong with my mech
5.) Laverda's laser on my servo - disc only tries to spin clockwise when lid open! Conclusion: something wrong with my servo too!
6.) I then swapped the laser assembly from a working cdm9/44 in a Kodak PC860 into Laverda's mech - same issue - spins but no TOC, just ERR. Putting Laverda's laser ass back into the Kodak and it works fine.
7.) I noticed that on my player, the MN4264P-15 (DRAM chip) runs very hot, maybe hotter than the SAA7220. I later checked on Laverda's - it is warm but not hot on his. Need to check this point further.
8.) I put my machine away at this point, and went back to Laverda's - putting his servo/laser back into his machine. Same: disc running slowly backwards. Flea output looks OK scope, but to be sure I pulled the Flea out of my Marantz CD60 to confirm - still same.
9.) I then swapped the SAA7220 from the CD60 into Laverda's - still the same, disc running slowly backwards.
I now give up for the day
While removing parts from the CD60 I see it uses the same chipset as the Naim, so will study it's circuit in more detail tomorrow.At this stage I suspect I have separate faults on my laser and servo, and that Laverda's has a problem on the main board somewhere.
Has anyone ever had a SAA7310 fail? This is where the clock from pin 9 of SAA7220 goes to. And disc spinning backwards suggests clock fault?
Cheers, Richard
Dowser
Learning to bodge again..
Thanks. I'm going to check all voltages on Laverda's as a next step. Have you ever had problems with the MN4264P-15 (DRAM chip) - how hot does it normally run? I really wish I had a fully functional laser/servo combo...why did I manually stop the disc?!
Yes, I saw this - forgot to comment. Seems a bit weird, how many other pins does pin 9 have continuity too? And literally a short circuit?
Dowser
Learning to bodge again..
I don't think you can rely on checking continuity with a DVM while the power is on
Which 3 pins does your pin 9 have continuity with on your saa7220 (with the power off)? I can check this for you.
Dowser
Learning to bodge again..
Sorry, but when you say continuity, what do you mean - how many ohms are you reading?
For example, pins 12 and 24 are ground and 5v supply pins respectively - if they were short, as a result of the saa7220, the associated 5v reg would have gone bang
Continuity of a few kohms is possible - I'll measure one of mine tonight - but equally is not a fault condition.You need to be careful measuring in circuit - only sure fire way to tell is to remove the saa7220 from circuit and then re-measure. I suspect this is a red herring though - will confirm the ohms i get between saa7220 pins 12 & 24 later tonight.
Richard
iqpi
Member
By continuity I mean they are connected to each others.
Mine reads the same in circuit ~381ohms but not necessary indicate the IC is alright (for mine anyway).
The DRAM chip gets very hot and so is one of the other 317 regs. To me this indicate something is not right, yours DRAM is also running hot. Maybe the fault is related to DRAM chip, a schematic would help in this situation.
Dowser
Learning to bodge again..
There is no schematic
See below - I ignore DRAM chip heat currently - using a scope both look similar, and the one with the platter spinning slowly backwards is not as hot as the one that does not read TOC after 2 or 3 blips. How fast is yours running backwards? Note that both of mine use the CDM9 Pro laser and servo board...a definite difference from yours.My work tonight;
Compared clock signal between my CDi (stock clock currently), and Laverda's (running a Flea I had in my Marantz CD-60). They're different, but am not sure if it is significant - this is from pin 9 of the saa7220p/b;
Mine;
Laverda's;
Significant? I assume not at this stage.
Then I compared connectors into the servo board of both machines - using below image descriptor for connectors. I'm focused on repairing Laverda's currently, as I assume easier to fix, but also looking for differences to my machine too (which defvintely has a servo board *&* laser mech fault;
Main take-aways;
- Laverda's machine has a waveform coming into connector 4/pin 4 that mine does not - this is what is causing the platter to spin slowly in reverse
- My machine has 2.5v on one of the lid switch pins (connector 3/pin 4) which Laverda's does not
- While the MN4264 DRAM chip definitely runs hotter on mine than Laverda's, all waveforms and voltages are similar - I ignore for now
So then I traced the waveform causing platter to spin backwards on Laverda's machine back to main board - it comes from pin 7 of an NE5532 opamp. Pins 5 & 6 have a bit of noise but look OK. Plus and minus 10v fine on pins 4 & 8. There is a perfect sine wave presented to one of the pins 1-3, can't remember which currently - and I have no idea yet of both channels of this dual opamp perform same function currently.
Drawing;
Given up for this evening, need to eat. Will compare with my machine tomorrow.
If anyone has any input or advice, please let me know. I really am flying blind here...but will fix these f*cking CDPs
Thanks, Richard
iqpi
Member
Mine is at moderate speed, I havent try the sticky tape measurement but definitely not at warp speed. Feeding off a constant control votage of 4.3V off the NE5532 via pin 7. Pin1 of 5532 also has a constant output of -4.3 V but doesnt make it to the Vc of the motor connector. Pin 2 has input from the 4066 opamp and the system controller IC.
I replaced the 5532 and 4066 and even the LM324 , made no different.
What is the voltage of pin1 on your NE5532?
Aaron
Dowser
Learning to bodge again..
Dammit - looked at this again tonight, moved laser mech out of way to be able to measure around opamp- thing span backwards for 30 mins, then I went for a cigarette - come back and it has stopped. Tested, it still has a little backward inertia, but try a disc and it reads TOC. It's been playing on repeat for 5 hours now, fecking thing!
russel
./_dazed_and_confused
If you smoke then the laser can get fogged, lasers on CD players can fail or go low output, particularly early ones, carefully clean it with alcohol and it may work for a bit longer.