Help please: Harman HD740 pickup trouble

[Extreme_Boky]

Originally posted by hiwiho
Boky,
it's pin41 at the 9240m, too. But unfortunately the chipset features some automatic gain control - it doesn't matter how i turn the laser current, it's always 2Vpp at pin 41. The pattern colapses just when the drive doesn't recognize any disc anymore.

Then I remembered a friend had the same player, grabbed my Hameg and i opened the friends Harman. 2Vpp at pin 41. I implanted my drive and had the same sort of misbehaviour

At home i tried the last i could do and replaced the ribbon cable of the new laser with the one of the old - just in case the ribbon was broken. But it wasn't.

I guess now it's the second time i got a defective laser from this crappy shop here - i won't go there again but will order online from well reknown distributors in the future. Rather pay shipping than pay for waste and twice

Thanks for your thoughts and patience!

matthias

Okay, in this case and at this point you'll need the circuit diagram to be able to tell if pins 1,2,3 and 4 are used for disk reflectivity detection. Is the mechanism used in over-scanning config? In other words, does the lens scan the disk as soon as the "mechanism" detects the disk is present, immediately after you insert the disk in the CD player? The spindle motor should start spinning really slowly during this detection, and the laser pickup should start moving slowly from the inner area towards the outer area, and then quickly come back to its "home" position = reflectivity detection finished. You can visually check this.

Boky

[helios999]

i have the manual service

my mail helios999@free.fr


i have a nad c540 player broken (with laser sfp-101 5/8 ) and i think ( i don't find the transport of my nad ) we can swap for a wsl-2130ccm (kss113c)
i hope find a used kss113 for this swap
someone knows if it's possible ?

[hiwiho]

Hey all,

sorry i suddenly vanished I was sick of fooling around with a new weak laser back those days.

I now want to give a short feedback to the contributors:
Lately i got a DX7711 (sfp100s) for little money with a weak laser. So instead of just buying one Sanyo pickup, i bought two and thus afforded another new SFP101 5/8.
I decided to first swap lasers on the HD740 to get into the groove again. Obviously the "new" one i got before was already defect - with the brandnew, the Harman now again plays perfect!

Thanks guys!

Matthias

[Mooly]

Result.

[hiwiho]

Originally posted by Mooly
Result.

Yes, a good one with the HD740 - a bad one with the Onkyo i tried to fix afterwards


Matthias