Re: PIONEER PD-T505 schematic

If I wish to spend mony on it , I would have done that ...

Maybe someone has a PDF- file of it ?

wim

"Alex" snipped-for-privacy@no.spam.com.au> schreef in bericht news:bf54st$qnb$ snipped-for-privacy@lust.ihug.co.nz...

How about telling us whats wrong with the unit, it might be a well known fault. Theres plenty of people in this NG who have repaired many Pioneer cd players who could also assist as well. I have seen relatively little go wrong with Pioneer home cd stackers as far as the circuitry is concerned, its quite often been a case of a problem with the optical pickup/worn spindle motor or some other silly mechanical problem (just gen servicing) or maybe a mechanical alignment problem.

Alex.

so the skipping happens straight away? or only when the volume is raised and some vibration is introduced to the unit?

did you check the laser lens closely for dust? (dont do this with the unit on). I need to know If you have checked the things I suggested In my last email. if you do find the laser lens to be dirty, **dont** clean it with any solvent or water. U can clean it with a clean, dry cotton swab, or u can use a pure alcohol based liquid such as isopropyl alcohol if it is really bad.

disconnect the unit from the mains, you will notice a sled gear (this assists movement of the laser pickup from the inner most area to the outter edge during playback)

try and move it by hand and see how freely it moves. Of course, the other option is to place the unit in test mode and using the track up/down keys observe the behaviour yourself.

Theres a couple of ways to check the spindle motor. One is to disconnect it from the servo, connect it to a 1.5v power supply and hook up a meter in series and watch how much current is being drawn. If you find it drawing more than 600ma, time for a new motor. Although this method will not reveal a noisy motor, which can cause skipping too. With the unit turned off give the motor a quick flick in the clockwise direction. If it doesnt spin at all or sounds noisy, the motor is worn. U can try a very small drop of light oil into the shaft of the motor and see if this frees it up.be careful doing this.

skipping is not normal behaviour. component deterioration after an extended period of use IS normal :) The repair cost could go either way actually. If it is only a spindle motor that has to be replaced or a plastic gear, it will be quite cheap to fix. Should the laser pickup be faulty, this can get rather expensive. You would have to find out for your friend how much he is willing to spend on fixing it.

the entire laser assembly does not have to be replaced, individual components are usually available.

The unit should be able to handle some degree of vibration. This could be signs of a weak laser or a worn spindle motor.If you want to check the lasers strength, you're going to need some specialised equipment and tools. One would be an oscilloscope, and a test disc that conforms to a special standard. Using these tools, u can place the unit in test mode and check many things. One would be the RF amplitude of the laser.

In the service manual, they will give u a nominal peak to peak value of the RF signal, this varies depending on the circuitry and of course, the laser.

typical values are 800mV to 1.2v p-p

obviously if you check this and find the amplitude to be 200mV p-p. the laser is weak and should be changed.

There are other things to check as well besides RF.

You must be prepared to do this if you want to check everything yourself. or you can take a blind guess and change the laser.

I suggest checking what i said earlier in this email and in my last email, and posting the results..

regards, alex.