Technical info about PS1 PU-18

[master991]

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...pg&res=landing.

500X.jpg

Thanks

[master991]

Anyone can help me?

[svotib]

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

[master991]

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

[svotib]

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.You need a service manual SCPH-55xx, there are all the waveforms.Good luck.

[master991]

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

[svotib]

Hi!Sent a personal message.

[master991]

Oh thanks! PM'ed too :)

[H360]

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

LOL.

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

[master991]

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 ???

[CodeAsm]

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

[Bad_Ad84]

https://dl.dropbox.com/u/28488139/SC...e%20Manual.pdf

Shitty scan, but its the 550x service manual.

[master991]

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

[H360]

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 ???

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.

[CodeAsm]

Thx bad_Ad84 en Haunted,

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

[master991]

Thanks for the info haunted

There is no big hardware difference between the 7500 series and the 5500 series for your information.

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

[Bad_Ad84]

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.

[master991]

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
Thanks for the manual Bad_Ad84


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?

[Bad_Ad84]

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

[CodeAsm]

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