PS One shorting out?

[Frigo]

I recently picked up a lot of a NES, Playstation 1 and PSOne systems for 20.00, with the intention of either fixing them or modding them. The Playstation 1 system works fine, and is awaiting modification (I've tossed out the MM3 chip in favor of a parallel port loader), and the NES needs to have the CIC chip shorted out (constant blinking grey screen), and is awaiting RGB modification, along with a new 72 pin connector. The PSOne, however, is exhibiting some strange behavior, in that it boots up fine when the lid is open, but seems to short out when the lid door is closed. Here is a quick video I made (sorry about the audio level; my son was asleep in the next room).



In case you can't hear the audio, what happens is, is that I can power the PSOne on with the lid UP, and I get the full intro and boot to the GUI. Once I close the lid during ANY point in the bootup process, the unit seems to short out, as the CD drive attempts to spin up but ultimately fails. The a/v out also reflects this, as the image on the screen completely blacks out with red flashes as shown in the video. I've swapped out the drive with a drive from a Playstation 1 model, which doesn't fit, but exhibits the same issues with the lid latch pressed. If I disconnect the drive completely and press the lid latch down, nothing happens - the system boots to the GUI as if the lid were up. It's only when there's a signal sent to the cd drive via the lid latch that shorts out the system. Same thing when I plug the power connector for the drive into the system board but not the data cable.
Has anyone ever seen/heard of this, and, more importantly, is it fixable?

[WhereEaglesDare]

does it exiibit the same symptom if you power it up with the lid closed?

[Frigo]

does it exiibit the same symptom if you power it up with the lid closed?

Yeah, it doesn't matter when the lid is closed, as soon as it does, the system shorts out.

[northerngames]

check the lid switch assembly pins for cracks in the solder joints and also where the power plug goes onto the motherboard check the power port pins solder joint's for cracks too.

[Frigo]

check the lid switch assembly pins for cracks in the solder joints and also where the power plug goes onto the motherboard check the power port pins solder joint's for cracks too.

Thanks, I was actually planning on doing this tonight, but the problem I have is that the solder joints are all surface mounted instead of through hole, so I'm having a hell of a time getting to the joints. I'm going to go back to it tonight with a desoldering braid and see what happens, but any other suggestions on how to get at them are welcome.
 

[RandyT]

I could be way off on this, but here's what I see happening;

With the door open, the CD doesn't try to spin.  So it's probably the act of spinning up the CD which causes the unit to shut down, not the door switch, which seems to be doing what it is supposed to.

It looks an awful lot like a bad CD motor, which is pulling too much current ( and/or has a shorted winding) which kills the system.  If you can disconnect the power to the CD motor and the machine stops doing what you show, then that would probably confirm the motor, or something associated with giving it power, as the culprit.

RandyT

[Frigo]

I could be way off on this, but here's what I see happening;

With the door open, the CD doesn't try to spin.  So it's probably the act of spinning up the CD which causes the unit to shut down, not the door switch, which seems to be doing what it is supposed to.

It looks an awful lot like a bad CD motor, which is pulling too much current ( and/or has a shorted winding) which kills the system.  If you can disconnect the power to the CD motor and the machine stops doing what you show, then that would probably confirm the motor, or something associated with giving it power, as the culprit.

RandyT

I would think that too, if it were not for the fact that I see the CD motor start to spin about once every second as soon as the lid latch id powered down. I even tested it with a known good cd drive that I pulled from a working Playstation. Both drives also work in the working Playstation (I may have not mentioned this).

[RandyT]

I would think that too, if it were not for the fact that I see the CD motor start to spin about once every second as soon as the lid latch id powered down. I even tested it with a known good cd drive that I pulled from a working Playstation. Both drives also work in the working Playstation (I may have not mentioned this).

Then it may be a transistor, or something like that,  responsible for delivering power to the motor.  Could even be a bad power supply that works fine until the motor starts drawing current.  Have you tried a different one?

[Frigo]

 

That I haven't done. I was so wrapped up in narrowing down the cause at the connector level that I totally spaced it.
I'll see if I can get a replacement @ The Shack or somewhere close tonight.

[RandyT]

That I haven't done. I was so wrapped up in narrowing down the cause at the connector level that I totally spaced it.
I'll see if I can get a replacement @ The Shack or somewhere close tonight.

Don't spend too much on it, unless you can use it elsewhere.  The old PS1 had a power supply board which took the mains supply and converted down to the different voltages required by the electronics.  This one probably has the same type of thing, but converts the 12v (or whatever it is) down.  It could be one of those components, and I'm going to guess that they are on the main board, given the compact nature of the unit.  On the old units, it was a board swap.  But it's probably not going to be so easy with these, unless there's a separate little board.

So, in short, if the main power supply is good, it's liable to be a tough fix.

[Frigo]

That I haven't done. I was so wrapped up in narrowing down the cause at the connector level that I totally spaced it.
I'll see if I can get a replacement @ The Shack or somewhere close tonight.

Don't spend too much on it, unless you can use it elsewhere.  The old PS1 had a power supply board which took the mains supply and converted down to the different voltages required by the electronics.  This one probably has the same type of thing, but converts the 12v (or whatever it is) down.  It could be one of those components, and I'm going to guess that they are on the main board, given the compact nature of the unit.  On the old units, it was a board swap.  But it's probably not going to be so easy with these, unless there's a separate little board.

So, in short, if the main power supply is good, it's liable to be a tough fix.

Well, it came without a power supply, I was using a multi voltage supply that came with a NES I had bought earlier in the year and never tested (I have a few projects going on at any given point in time, so it's entirely possible that this PSU is faulty - the NES it came with showed similar issues to the PSOne), so I'll need a replacement, anyway. And if it turns out not to work, then I can always take it back. Shouldn't be too hard to find a 7.5v, 2A adapter with a positive connector.

[Frigo]

Update: I think I may have figured it out - I was using a universal adaptor and - simple mistake - I didn't check the amperage. It's putting out 850mA when the original adapter put out 2A. So, I ordered a replacement from eBay (Radio Shack wanted 40 bucks for a replacement!) and it should be on it's way shortly. I figure when the drive is requesting access, it's too much power for the universal to handle and it craps out. We'll see.

[RandyT]

I was using a universal adaptor...

That would have been good info for the first post

[northerngames]

yeah that is definatly the problem lol

as randy mentioned prior the draw from the drive is enough to put it over board and strain the power to cuase error's.

there's power going to the laser assembly snake motor to move the laser and the disk motor to spin it so it draws just as much as the mobo itself if not more.

[Frigo]

I was using a universal adaptor...

That would have been good info for the first post

Yeah, yeah... I do this stuff all the time - I always overlook the most simplest of things.

[Frigo]

It was the plug. The laser is kind of flaky, but I think a good cleaning will fix that. Next step is to see if I can mod it. =P