Sony PS1 model SCPH-5502 trimmer RV703 broken.

Discussion in 'Modding and Hacking - Consoles and Electronics' started by arny91, Jan 19, 2014.

  1. arny91

    arny91 Member

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    Hi, i've bought a ps1 scph-5502. While i was trying to tune rv703, (just by putting a game with a long fmv on it, as i don't have an oscilloscope) i spoiled it. I managed to desolder it. It's a 47k carbon smd variable resistor, according to the service manual. Anyone knows where can i buy a similar trimmer?

    P.S: These pots aren't rotative, right? (do they have a limit?) If i had known before, perhaps it would still work.
     
  2. master991

    master991 Enthusiastic Member

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    Use a standard pot, and next time don't touch things that you don't know :p
     
  3. arny91

    arny91 Member

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    Using a standard pot requires soldering wires and means having another mobile part inside the case (unless i tape it), not to mention that there's the risk of lifting the pads if the wires get pulled. I found those:

    http://www.aliexpress.com/item/100p...tentiometer-Trimmer-Pot-3x3mm/1611212781.html

    i think they should be good.

    And if you want to know why i moved the pot, well, this ps1 came totally dirty, with a big picture of dragonball on the top, attached with stick and vinyl glue together, and of course, with the lens and push-pull not calibrated. It took me days to remove the sticker and to clean the whole case. It has a ksm-440adm laser unit, which works at 24,4 mV, the voltmeter signed less than 14 mV. I raised it to the right value, but it had anyway fmv skipping problems. As i had fixed the same problem on a scph-5552 in fall 2012, i tried rotating little by little the rv703 pot. But now that i think about it, that pot had the wiper at minimum since i opened it. After various tries, i found this pdf:

    http://bitokorleone.tripod.com/atlasman.pdf

    It's for the SCPH-100x, but i think it's good also for the other. I placed the pot with the wiper at ~2 o'clock, and it skipped fmv less than before. But it was too late: the trimmer was spinning freely.

    Now i have to change and adjust that.

    By the way, i was also thinking about buying an oscilloscope, but in the service manual, i see there is an "adjustment jig" between the oscilloscope and the ps1 motherboard's test points CL710 and CL751. Does anyone know what is that thing?
     
  4. master991

    master991 Enthusiastic Member

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    You shold have play with the pot on the ribbon cabl, not with the push pull, you can also use a fixed resistor or use a small pot as said above.
    I don't see why spend so much for a pot and how you lif the pad if you a clear job :p

    Honestly i don't know what is that damn "adjustment jib", and as you can see, you nedd also a special CD called “QA-DISC” or “AGING DISC" and a SCD-2700 DISC. Maybe someone more expert can help us..

    Buona fortuna paseano :p
     
    Last edited: Jan 19, 2014
  5. Mechagouki

    Mechagouki Site Supporter 2013,2014,2015

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    No PS1 is worth this much effort.

    Unless they cost more than $10 USD in Italy of course.
     
  6. arny91

    arny91 Member

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    Would this have been useful? I don't think there are any improvements by raising the laser intensity more than necessary. And, as i said, both laser intensity and push-pull were surely misaligned.

    You mean it isn't worth the effort? Anyway, with that price you get not 1 but 100 of that pots, i don't know what to do with all those pots, and if i could buy less of them for a minor price, i'll try.

    Regarding a possible fixed resistor, what value should it be? I also have a ps1 SCPH-9002, and it doesn't have any rv703 trimmer. Does it use a resistor for push pull adj?

    Grazie e speriamo bene!
     
    Last edited: Jan 20, 2014
  7. master991

    master991 Enthusiastic Member

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    No, from 7502 RV pot was removed
     
    Last edited: Jan 20, 2014
  8. arny91

    arny91 Member

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    Ok, has it been replaced by a fixed resistor on newer consoles?
     

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