REPAIR GUIDE - Super CDROM2: Total capacitor replacement chart

[thesteve]

it runs all over, but I've seen the issue under the board near the 1000uf cap

[thesteve]

The crackles are from that voltage

[pnauts]

from that voltage ? the 0.9V, what is yours on connector ?

here are an image of what I think is wired (except error) all discrete components are close each others I wrote the measured values.

http://postimg.org/image/8ipv7j2ix/

when I use the DMM on the Q308 base, more crackling noises.
I think about a problem on Q308 ? what do you think ?
still dirty residue in your opinion ??

Thanks.

Edit: ok my pin is the one you talk above (antithump) that should be close to 0V ?

[thesteve]

my tests oc crackling units was 0.9-1.2
good was 0.0-0.15

[pnauts]

I'm pretty confident the issue is fixed, because I removed the 1000µF, there was capacitor's leakage, the varnish and the via was attacked.
I washed all and set a product to minimize contact resistance, and changed the capacitor.
For whom want to know, I answer to one of my question, yes a capacitor can have a good value but be defective.
I'll test tomorrow and keep you in touch.

[BlueBMW]

Did you replace all the capacitors or just some of them?

[pnauts]

for the moment I replaced 2 leaded capacitors, I didn't change SMD.

[BlueBMW]

Ahh....  I would highly recommend you just go ahead and replace all the capacitors.  Its a pain but will save you headache in the future.

[pnauts]

well, I'll perhaps change leaded and the ones which are under the top RF shield.
Others are accessible later just by removing the laser unit.

[pnauts]

Hi, after cleaning under the 1000µF and had the capacitor changed, sound is better but I'm not sure with the results.
Volume from SCDR² AV connector is lower than Console AV connector, is it normal ?
The voltage on pin is around 0.6V, I don't see any residues on the coper wires and vias between the components mentioned in my post above. The diodes measured on Q308 and Q309 (PNP) are ok.

edit: to be more accurate, the voltage is around 0V but after something like 10 minutes of run, with an initial voltage of around 1V with cold start, so there is a drift but for the moment I didn't succeed to find out. The volume on SCD² seems lower than direct to console anyway.
I'll reflow welding around this components tomorrow.

[BlueBMW]

I've typically noticed it to be a little quieter from the SCDROM2 versus the core system.

[thesteve]

that voltage should start higher then bleed off (sounds like its doing that now)

[pnauts]

then the sound beginning a few lower and a little crackly is normal ??
I measured a low resistance at ZD303 (around 90 ohms between A-K), I don't find where it come from.

[pnauts]

Up, please.

[pnauts]

I think it's fine, I changed some others leaded capacitors + test with RF shield, the voltage is around 0.5V at start up then decrease, a SCDR² is reborn, great ! and thanks for help I appreciated it.