Absolutely correct.
It could be collapsed elastomer suspension mounts, guide rail damage/wear, lubrication of the guides, the linear motor windings could be fouling in the rails/magnets/gaps and the spindle motor thrust and/or sleeve bearing could be sticking/dry/worn. Pretty sure IIRC the PD91 has a BSL main motor, so it should be ok.
I wouldn't touch any electrical adjustments until the entire mech had been thoroughly checked out. The fact it plays perfectly when tilted means the laser Po pot shouldn't be touched. And if the 'tech' can't show you his laser power meter- walk out of the shop.
I presume most of the above few posts are aimed at me.
Please read my original few posts. NOWHERE did I say adjust anything. I said CHECK the adjustments.
As a 'tech' of 37 years experience, the majority of which was with a Pioneer Authorised Service Centre and attending numerous training courses with the renowned Ken Clements during the 90's (when this Player came out) I know that the first thing to do after removing the top cover is CHECK ALL THE ALIGNMENTS. Note :- CHECK.
This tells you so much. If they're all OK, then you know the electronics are almost certainly OK and there's almost certainly a mechanical issue.
If they're not right, as per the Manual, THEN and only then an attempt should be made to see if they're align-able back to spec'n. If they're not then start finding out why.
I have had many FOCUS IC's failed on Pioneers. TA7210/7240 from memory, but it's a while ago now since I looked.
No-where have I said to go blindly tweaking the alignment pots, no-where.
As I said in one of my earlier posts, the beauty of Pioneer players from that era was that they were fully alignable. Follow the manual and even the diffraction grating adjustment is easy.
There is a check for Laser Power, and yes, I own a Meter, but there is also a check on all Pioneers for RF Level where the adjustment is for RF pk-pk. A power meter is not needed for this and a good 'tech' knows not to violently turn any adjustment pot. I have never known any Pioneer Laser be destroyed performing this adjustment, in 37 years.
Other Manufacturers Lasers, yes.
P.
Please read my original few posts. NOWHERE did I say adjust anything. I said CHECK the adjustments.
As a 'tech' of 37 years experience, the majority of which was with a Pioneer Authorised Service Centre and attending numerous training courses with the renowned Ken Clements during the 90's (when this Player came out) I know that the first thing to do after removing the top cover is CHECK ALL THE ALIGNMENTS. Note :- CHECK.
This tells you so much. If they're all OK, then you know the electronics are almost certainly OK and there's almost certainly a mechanical issue.
If they're not right, as per the Manual, THEN and only then an attempt should be made to see if they're align-able back to spec'n. If they're not then start finding out why.
I have had many FOCUS IC's failed on Pioneers. TA7210/7240 from memory, but it's a while ago now since I looked.
No-where have I said to go blindly tweaking the alignment pots, no-where.
As I said in one of my earlier posts, the beauty of Pioneer players from that era was that they were fully alignable. Follow the manual and even the diffraction grating adjustment is easy.
There is a check for Laser Power, and yes, I own a Meter, but there is also a check on all Pioneers for RF Level where the adjustment is for RF pk-pk. A power meter is not needed for this and a good 'tech' knows not to violently turn any adjustment pot. I have never known any Pioneer Laser be destroyed performing this adjustment, in 37 years.
Other Manufacturers Lasers, yes.
P.
Hi percival007,
You did not read my post, or you misunderstand what I am saying.
You did not read my post, or you misunderstand what I am saying.
Hi Pericival007
Please don't take my advice to the OP as an attack on you, apologies if it came across this way. I think we are both tending to think it is a mechanical issue. I've also have done Pioneer factory training back in the day, but some manufactures don't understand not every alignment can be checked thoroughly when your in a small workshop with time constraints to get the repair done or without the correct jigs. Didn't many service manuals also expressly ask for the VCO free run to be adjusted as an alignment , was this ever off frequency?. Also I've looked into this units laser it also has Radial and Tangential alignements...so lots of fun there to be had, I do disagree diff grating is an 'easy' alignment though
I still have my Mini-disc laser power meter somewhere lol
Please don't take my advice to the OP as an attack on you, apologies if it came across this way. I think we are both tending to think it is a mechanical issue. I've also have done Pioneer factory training back in the day, but some manufactures don't understand not every alignment can be checked thoroughly when your in a small workshop with time constraints to get the repair done or without the correct jigs. Didn't many service manuals also expressly ask for the VCO free run to be adjusted as an alignment , was this ever off frequency?. Also I've looked into this units laser it also has Radial and Tangential alignements...so lots of fun there to be had, I do disagree diff grating is an 'easy' alignment though
I still have my Mini-disc laser power meter somewhere lol