PS1 Help

I have an SCPH-1001 swapped with a KSM-440-BAM laser and it's working smoothly. My little problem is that some scratched discs depending on the game will give me little skips in the FMV. I also have discs with disc rot and one with a ring damage. Is this the cause of the FMV skip? Are TotalConsole KSM-440-BAM's good?
Would disc resurfacing or buying whole new copies of games help? And yes my laser is fine.
Please let me know. I tried them in a SCPH-7501 and they were skip free. Is because the 1001 has a different CD-ROM chip? I would like to use the 1001 because of the RCA Jacks.


This is what i'm talking about.
This is my Spider-Man and my Star Wars Episode 1 Discs.


Here is my Spider-Man disc (Notice the ring damage) Is that disc rot?
What is that?


And my Star Wars Episode I (Sorry you can't see the scratches good in that photo but i can see them in real life):



Is this is what is causing my 1001 to skip even with a good laser?
Do 1001 PlayStations read scratched discs differently?

 

when the scratched discs run on the 1001 do they skip at the same point every time or is it random ?

 

Well it's random. And yes i have a KSM-440-BAM laser. My 1001 does not have an ACM drive on it. Would resurfacing or buying new copies help. Well for the Spider-Man, It skips a little on the last part of the beginning of Spider-Man 2000 where the fog comes on. Could it be my disc at fault?

 

I'm not really sure what you're asking for... you say the discs work fine in another console. So wouldn't that point to your laser not being as good in the other console?

I always suggest cleaning the laser, it seems to be very under-rated.

 

I haven't personally tried the TotalConsole pickups, but according to people I know and trust they are identical in both appearance and functionality to the original Sony ones. It's quite possible they really are old stock Sony production as they are claiming - and even if they aren't, they are really good copies. I don't think this is your problem.

The short answer to your question is that what you are seeing is perfectly normal - even a correctly functioning SCPH-1001/1002 is significantly less tolerant of disc damage than the newer consoles are. The basic reason for this is that there are three things that need to be controlled to read an optical disk; the vertical position of the lens ('focus') the radial position of the sled/lens assembly ('tracking') and the speed the disc is spinning ('spindle') - all three of these are referenced to the signal being read from the disc.

If the read signal deteriorates (say because of major scratches on the disc or because of the holes in the reflective layer in the disc characteristic of disc rot) then the reference signals these servos use go away and they have to try and hold their position until the read data signal comes back.

The older (PU-7 / PU-8) boards use a hybrid servo system - the focus and tracking servos are analog but the spindle servo is digital - analog servos work perfectly with a good quality signal, but can sometimes misinterpret damage on the disk as a position error. When this happens, the servo starts to move the lens in the wrong direction and if this is followed by a signal dropout the lens can be badly out of position by the time the signal comes back - if the focus servo gets confused then the drive can't read anything at all and has to find the disc again (this is what causes the clicking noise - when you lose focus lock, the CD drive controller retracts the lens and that noise is it hitting the lower endstop). If the focus stays locked, but the tracking goes out then once the signal comes back the drive will find it's out of position and will seek back to where it should be - this delay while it finds the right place on the disc is what causes the FMV breakup.

On the later (PU-18 / SCPH-55xx) boards, the hybrid servo was replaced by a fully digital servo. This design carries out much more fine-grained analysis of the data it gets back from the disc (for example, if you are getting deletion symbols out of the EFM decoder it's very likely that the focus and tracking data are suspect) and since it's digital it's much better at holding the current position which increases the probability that the lens will be in the right place at the end of the dropout, and can just continue reading.

TL;DR - don't worry about it - it's likely that your SCPH-1001 is working fine (I.E. as well as it ever did) and replacement copies of the games that are causing you problems with less damage on them will work perfectly.

 

Great detailed info. Always fun to read your techical posts TriMesh

 

Hey, I just read your comment. Are you saying that an SCPH-1001 will damage my disc since you said "sometimes misinterpret damage on the disk as a position error."
Before i buy a new copy or resurface my copies, Would this help even more to make the 1001 read better?
Does it matter what position of the BIAS and GAIN pots are in.
Look at this picture:
Does the green mean good
Does the red mean bad?
What does the yellow mean?

Remember my 1001 does not have an ACM drive in it.
Would seized or worn CD-ROM motors cause 1001/1002's to spin crazy fast?
That's what would happen to me if i used an AEM or a badly worn ACM unless console was on it's sides.

 

No. It just tends to cause the drive to lose track and take some time to recover, which is obviously bad for FMV.

That photo is only useful if you have access to a scope and can monitor the eye signal test point - it's illustrating what happens to the signal as you move away from the optimum setting. It doesn't show the actual pot position needed since that will vary between units. Note that claims you can set the pots up using a multimeter are equally bogus - if there was a specific resistance value that worked best for all units then Sony would not have put a pot there in the first place.

If the disc is overspeeding, the most likely cause is a weak laser diode or dirty components in the optical path. The disc speed is controlled by monitoring the rate that data comes off the disc, so if the signal is very poor the servo may try to speed up the disc to compensate - this is something else that's more likely to happen on the old boards since the newer CD control chips have a better spindle servo.

For all practical purposes, the -BAM is the same as the later metal frame -ACM. The only changes are that the flex cable has a pull tab on it and the color of the top cover.

 

So you're saying if the board is dirty the SCPH-1001 can overspeed? Because this is what happend to me with a bunch of 1001. This is the model of PS1 which made me rage quit and made me cuss at a Fix It Phil group.

 

He's saying that the servo circuit will speed up the motor if the signal is weak, which if possibly caused by a weak laser diode or if there is dirt in the path of the beam (i.e. the laser or disc is dirty). Not the board.

 

What am i gonna do? I'm planning on buying replacement copies of games that are not scratched. Would that solve it 100%? Because the 1001 is the model of PS1 which made me rage quit and made me cuss at a Fix It Phil group and it's driving me crazy!

 

A bad optical pickup can do that on those old units, but there are many possible causes for it. A bad laser is one, and contamination on the optics is another. Dirt on the PCB shouldn't be a problem.

If most of your games work OK and there are just a few that don't, then it's likely those discs are bad. The basic issue here is that the older (PU-7/PU-8) consoles need better media quality to work properly, so just because a certain disc works OK in (I.E.) a SCPH-7501 doesn't mean it will necessarily work in a SCPH-1001. Incidentally, the same thing applies to the optical pickup - you might have a heavily used PSone that has a worn but still working KSM-440BAM in it, but when you put that same pickup into a SCPH-1001 it doesn't work realiably. This doesn't necessarily indicate that the SCPH-1001 has a hardware problem.

 

UPDATE: I tested the Spider-Man disc in the 7001 and 7501 and turns out it was doing the same thing. It was skipping on the Neversoft logo. You guys were right, It is the disc that is bad. Would buying a new copy help?

 

If your disc is bad then obtaining a good copy would help. You could try resurfacing it but I don't know how effective it really is. Maybe others who have tried it will chime in.

 

Yeah, if it's bad enough to mess up even in a 7501 (which has a very good servo system) then it's pretty clearly a bad disc. I would just get a different copy and see if that works - the apparent delamination around the hole for the spindle suggests that one was stored in poor conditions at some point.

 

UPDATE: I tested more games in my 1001 and they were skip free and had minor scratches. I had a little problem with Tony Hawk 2, It would hang on a black screen and stop spinning and make me punch the PlayStation out of anger. I cleaned the disc and it's working again. This is why i go for newer PS1 models. The 1001 is driving me nuts and making me want to destroy it out of anger! I've had it!!
Also is there a way we can upgrade a servo to a SCPH-1001 to have the SCPH-7501 and newer servo?

 

Sadly no - it isn't a simple component replacement, Sony pretty much completely redesigned the CD subsystem in the later models. The new chips have different pinouts (and in some cases are in different packages) and also required significant changes to the control firmware so even if you could somehow manage to install the newer CD DSP and RF amplifier the firmware in the HC05 wouldn't know how to talk to it.

 

It's because of the limitations of the system that they came up with better designs - you really cannot expect it to be as good as a later model when it comes to robustness. If it was that great, then they would not have invested resources into changing the design.

These devices were not designed to be user-serviceable either, so you cannot expect to be able to repair one without the necessary skills, tools and knowledge. It's not like Sony even released the service manuals for this model anyway, so you needed to fill in the gaps with technical know-how.

To me, it sounds like you just want a working set. If you're not planning to make it a point to actually learn how to fix one, you should really just let it go and get something that works.
The optical subsystem is also a piece of precision engineering, so exposing it to shock isn't going to help you.

 

An interesting but pointless fact is that the optical system in the PlayStation CD-ROM drive was probably the most robust of any of the machines from that generation - it was the rest of the CD transport that caused all the problems. All the optical components except for the turning mirror and the objective lens were implemented using a single holographic optical element and the HOE, laser diode and the PIN photodiode array were all built into the same chip. Everyone does this now, but back in '95 it was pretty bleeding-edge technology for a large volume consumer product.

 

Often the problem with scratches is they trap oil from your fingers and dirt and dust. Clean the disc with liquid soap and your problems will often go away.