Playstation 1 SCPH 7502 making clicking noise while disc spins no loading

Hi,

I've searched thoroughly for answers within the forum and overall in google and can't find a similar case solved.

So I've got a free PS1 SCPH 7502 that was sitting in a friend's basement, before I even open it, I plugged it in to make sure it was not dead and the first response I got was a weird mechanical clicking sound from the disc drive. I cleaned the console inside out and try again. With disc on or off, same sound; I put in a disc and pressed down the "button" to simulate the lid was closed and notice that the discs start spinning (that's when the clicking starts) it spins for a few seconds and when the spinning should get 2x faster it stops, it doesn't load the game and it goes straight from the Sony Computer Entertainment screen to the Main Menu. I've tried original PS1 games, music CDs and CD-Rs and all I get is the same response. I swapped the disc drive with another which works flawlessly in another 7502 and got the same result, tried the disc drive of the "clicking console" in another SCPH 7502 and it worked. Finally I placed the motherboard of the "clicking console" in a perfectly working one (again 7502) to rule out Power issues and again the clicking noise and no loading.

Finally, I'm assuming that there's an issue with the motherboard as all the other components seem to work fine with other consoles of the same model.

I notice that there's a chip in the motherboard, it has 3 wires solder to it and the motherboard and in the motherboard itself there are 2 pins joint together by a single wire (I will try to make a good pic to post it).

I'm not sure what to make of this, I thought that maybe it was a modding gone wrong, however it looks quite professionally done, the solder is not messed-up, the wires look good quality, the chip is glued with hot silicone to the mobo and even the aluminum plate that grants access to the mobo was solder back in place.

I'm pondering whether to desolder the chip but something tells me that maybe the issue is not chip related?

Another thing, my friend has no clue whether this unit ever worked as he bought together with like 4-5 more in a job lot and we has satisfied to find that 2 out of the bunch were already modded and working so the rest just sat in his basement until now.

Any clues will be much appreciated.

 

i think the clicking sound you are hearing is the laser lens moving up and down. i had a launch console that did it and the only way it would read a disc is if you turned the console upside down.

 

If you hadn't swapped the drive around then I would have said it was likely to need a new drive assembly.

It could be a problem with the mod chip, I'd remove it and see what happens. If that doesn't fix it then you're going to need to get the schematics and start measuring voltages etc.

 

Hi stevo9389, thanks, I tried the upside down, on the side, but it didn't work. Thing is the lens works just fine with other 2 7502s I have and doesn't make any noises in those.

 

Hi, thanks for the advice, I'll try removing the chip over the weekend, I wonder whether to get a solder wick or a desolder pump before actually removing the chip, just to make sure it won't get messy.

 

I use a pump and a needle nose soldering iron, but it still tends to get messy.
Photograph it in case you ever want to put it back though.

 

Hi there! I finally removed the chip and still no joy loading games (I used a solder wick, pretty clean job, checking with a magnifier afterwards it look perfect). I guess that there's some small component that gave up (maybe someone with the proper tools and know how could fix it).

 

If you really think it's worth the expense, replace the laser unit.

 

Can you check if the laser is actually emitting a beam?

You should notice a faint red dot on the top side of a cheap CD-R when powering up the console with the lid open but the lid switch tricked. To help see it, turn off all the lights.

If no laser beam is present, you should check the power section of the laser unit on the motherboard. Grad a copy of the service manual and check every IC part number until you find the Chip responsible for the laser's power management. Once you found it, probe the board following the service manual to check if any part might be broken.

It's a long process but you'll probably find out a burned or partially desoldered component this way!

 

I mean the laser, but you can just replace the whole unit above the shield, yes. Run it with a new unit without the lid on, holding the lid switch. That should run with no noise. If it comes back when you reassemble it, you've probably fitted something incorrectly or have some warped plastic.

Have you checked the spindle isn't broken?

 

Hi, thanks. bennydiamond, I'll definitely try that. Hmmm... actually I will need an oscilloscope right? a multimeter won't do here I guess.

BTW retro, I forgot to mention that after I removed the chip there's hardly any clicking noise and the and when I put a disc in and turn the PS on now the disc spindles for longer than before an faster.

 

Well, it's not unknown for chips to cause issues, either because of incorrect fitting or otherwise. However, you could find equally that it happened because something (e.g. the whole laser unit, or the top plastic) was misaligned, and taking it apart again realigned it

However, unless the controller has some kind of sensor for obstruction, it shouldn't stop. I'd go more with an issue with the laser, or perhaps a faulty controller.

You didn't buy a new laser unit, did you? If so, did it have the blob of solder you have to remove?

 

No, I didn't buy a new laser unit, I used one from another PS I have know to be in good working order.

 

I have a similar problem with my SCPH-1002. 2x speed simply won't work. 1x works and Audio CDs can be played but games can't be booted.

However, I have traced the problem to the "BA6397FP", a 4 channel BTL driver. I've tried using the one from the dead 9002 unit but unfortunately it uses a different chip/model and pinout is not correct.
Needless to say, after I desoldered it CD doesn't even spin now and laser shows no life. One of these days I'll replace "BA6397FP" and update my findings.

Anyway, seems to me like you might have the same issue. You can try ordering a new chip (make sure it's the same one) and replace the old one.

 

I don't think this is the same issue that the OP is talking about - that clicking sound is typically caused by the CD drive being unable to obtain focus lock - and if your machine was playing audio CDs then that can't have been the problem since both the focus and tracking servos have to be locked before you can read anything from the disc at all.

 

This happens to my japanese PSOne once in a while, the lens pickup is stuck. Gently move it to the outer edge and turn the console on with a disc in, it will stop doing that noise and will read the disc fine.

 

for me it sounds like a voltage issue. Old vorn out lasers might need a little different "settings" to be able to stay operatinoal, whereas a new laser assy propably runs just fine without touching those knobs.
Calibrating is one thing to try, or alternatively just replace the whole assembly.

when calibrating the laser's voltages (intensity/gain/bias) extreme values on either end will cause the clicking and in worst case fry up the whole thing.
i would suggest you read this and assuming that you have a multimeter, attempt to adjust it a little. however i can't stress enough that too high volts will cause permanent damage to the laser and/or motherboard. so only adjust very little, then test, then do it again. From my experience, adjusting gain is what makes or takes the clicking..

 

That guide it's totally useless. How that value are obtained? absolutely wrong.
Also that guide it's for the old scph 100X series. Later 750x series don't have trimmer for gain\bias reg.
He should only "play" with the trimmer on the orange flat of the cd drive.

 

well, i dont have a 750x to check so wouldnt know, assumed they would be there, so that's my mistake.

However, i have to disagree about the usefullness of the guide, as i've calibrated a good pile of machines with it, not failing to get them to work aside one that actually had a broken laser.

as far as obtaining the values go, personally i test this on the fly while running a game and adjusting while an FMV plays on the game. It's a pretty good way to see when the jittering starts or stops,
and for that matter, it always ends pretty near of the values listed in the guide when games start booting fine and running without stutters.

you shouldn't bash it without trying, othervise, if you insist this guide is incorrect and wrong, i'd like to see a correct method to prove it.