Technical info about PS1 PU-18

Hi people!
Someone can me explain what is the function of this trimmer on psone (scph 550X) motherboard PU-18
It's labeled with "RV703" (signed with red circle)
http://desmond.imageshack.us/Himg690/scaled.php?server=690&filename=500xb.jpg&res=landing.



Thanks

 

Anyone can help me?

 

RV703-trimmer,which regulates the sensitivity matrix of phototransistors.Without an oscilloscope is better not to touch.

 

WOW thanks!
Arg big problem, my friend regulated this without "sense"
Can you tell what can happen if the trimmer it's regulated out of standard?

 

Theoretically, if a clockwise rotation decreases the resistance, the sensitivity can be increased thresholds do not know, you need an oscilloscope.Otherwise the matrix is ​​simply burned.:sorrow:You need a service manual SCPH-55xx, there are all the waveforms.Good luck.

 

oh, big deal XD
Last question XD
Where is matrix phototransistor?
The service manual it's very hard to find....

 

Hi!Sent a personal message.

 

Oh thanks! PM'ed too

 

LOL.

By the way, you can find the schematics here: http://psdev.psio.com.au/downloads.html

 

LOL wath?
Can explain me better what does this trimmer sir?
And a PU -18 board it's a scph 550X. On your site the lowest manual it's a 750X ???

 

Manual for SCPH-55xx ? or is there almost no change? Thanks anyway anyone here
I do have a oscilloscope

 

Shitty scan, but its the 550x service manual.

 

Thanks Bad_Ad84 for the manual, i have already this version shity scanned
Tha main problem is, what is the Push-Pull Adjustment?

 

It's a trim potentiometer for the laser push-pull level adjustment. It must be 0.36Vp-p (peak to peak) on the wave (+- 0.025V). CL710 and CL751 are test points for the pot when adjusting.
The push-pull adjustment is an oscillator driver that will start tracking the signal when the laser pick-up crosses pits in a radial direction. Think of it as an auto-calibrating tracking mechanism for the CD-ROM's tracks.
There is no big hardware difference between the 7500 series and the 5500 series for your information.

 

Thx bad_Ad84 en Haunted,

Its indeed a shitty scan, but ill try to make something of it with the other manuals.

 

Thanks for the info haunted

Wrong. There is big difference in tracking-focus system between scph 550X and 750X (in fact in the last one there isn't any trimmer to calibrate the push-pull)
The only model that can be similar it's the scph 700X

 

Don't worry, he talks like he's the authority on all things PS1 - but all of that post was lifted directly from the PDF I posted above and reworded. Check page 5. Its obvious from his previous posts that was lifted knowledge.

I dont know why he continues to talk like he knows it all.

 

True! If I think he's working on the PSIO project... BRRRRRR:dejection:
Thanks for the manual Bad_Ad84 :triumphant:


P.S.: For the adjustment i need a special CD for the purpose? or I need only a PS CD or a normal audio CD?

 

Hes not making PSIO - someone else is. Haunted is just "Project Manager"

 

not all playstations has a pio... thats also sad.