PSone, poor laser or something else?

So I recently modded my PAL PSone with a onechip. The console was new when I got it and basically hasn't been used and was just sitting in it's box. Anyway it seems rather fussy and is what I assume is a laser problem, but I'm not sure.

Basically, it will boot originals (domestic and imported) fine. Some of the original games that are in not so good condition, either hang on the Playstation logo or fail to boot at all. Backups are a mixed bag as well. Some of my older ones on Taiyo Yuden discs, fail to boot. A fresh copy on a Verbatim disc, boots fine.

Do the old trick of sitting the console upside down and the originals, that aren't in great condition, start fine, as do the backups that refuse to start.

That seems like a laser issue to me, but this system is near enough new. Meanwhile, my old 9002 (I think, pal unit, no parallel port), will happily read the Taiyo Yuden discs and will happily play the originals that are not in great condition, in fact it will pretty much read anything you throw at it.

Is the Psone laser just not as good?

Not sure if the chip could effect anything, as I didn't really test it much before putting it in. I did have the same strange issue as this guy here after install

http://assemblergames.com/l/threads/psone-laser-louder-after-mod-chip-install.50846/

With the chip in, it was making, as that guy says a sound like a chirping cricket once the laser was running, but moving point 6 to the other side of the cap cleared that. Not sure if that could effect it, as I didn't really test much media with it on the other side because of the annoying noise.

Thanks.

 

Does it perform the same way with original + burned audio CDs?

 

Tried with the few audio cds I have (burned and original).

Some of them go straight to the cd player. Others seem to hang the system on the memory card + cd player screen. Strangely if I go to the cd player first, then put the disc in, all of them pick up and play fine.

 

Add your own capacitor to the line that goes to point 6. Use a small value, maybe about 1uF. Then attach to point 6 as per schematic.
I don't know if that modification affects the performance but it works for me.

Also make sure you solder your point 2 wire to the middle resistor of the bunch. Most install pics have this wrong.

 

Decoupling cap on the modchip always works for random issues I have had in the past.

 

Opened it back up earlier today, before checking the thread, just to confirm and it's definitely point 6 causing the havoc. Attached to the side of the cap indicated in diagrams and all the problems go away. All the non-booting copies boot, the originals in meh condition boot, everything is good except for the damn chirping sound.

Move point 6 to the other side, chirping goes away, but then it starts being fussy with discs. Disconnect the chip and it's fine, the originals in not so good condition are fine, all is well (obviously can't test the original imports with no chip).

I used the diagrams from here http://www.mmmonkey.co.uk/psone-modchip/, those have it on the middle one.

I'll try a cap on on line 6 then. I'm sure I've got some small ones around here.

I'll give this a shot as well then, thanks.

While I was in there, I grabbed a pic as well. I've not done any psone chips before, this is my current install



Using the mmmonkey diagrams and other than the chirping, everything is working fine (chip is upside down, so pin1 is bottom left, pin 8, bottom right), there's nothing wrong there is there? (Chip placement, wire lengths etc that could cause it?). I checked everything with a meter as well, so I know the connections are good. The metal shield fits back on fine with the chip there.

Thanks.

Edit:

Didn't want to make another post, so just adding it here.

I tried with a small cap across the chip and I tried with different value caps on line 6 and it still did it.

I actually uploaded a small clip of the sound here

https://instaud.io/zDF

The constant sort of zzz,zzz,zzz noise is the issue, soon as laser focuses, it starts doing that. If I disconnect point 6 it goes away, if I disconnect the chip, it goes away, if I move point 6 to the other side of the cap, it goes away but then seems to get fussy. I programmed the chip myself, maybe I messed up, but I would have thought it would just not work if that was the case.

 

I'm currently in the process of modding a bunch of PAL PSone consoles and stumbled across the exact same issue.
The OneChip-Code works great for PM-41(A) consoles (mainboard variants -11, -21, -31, -41, -51, -61), no unusual noises at all, but with the latest PM-41(2) boards (-71) I get a constant 'chirping' noise.

I have two of those -71 boards, both act the same.
The PICs pin 6 is supposed to be connected to signal CEI, pin 36 of IC732 (identical to the PM-41(A) variants).
Moving point 6 to the left side of the capacitor (signal CEO, pin 35 of IC732) fixes the chirping noise, but it seems to me that the drives reading abilities get a bit worse, especially with CD-Rs.

Does anybody have a proper solution or technical explanation for this?

I'm kind of amazed that there isn't more info available on the net regarding this problem, hundreds of people must have tried to install a modchip into one of these PAL consoles.

 

It's been a long time but I think the problem was that the modchip code never releases the CEI line from being dragged low.
It drags the line low as part of the modchip action but once it's done, the chip should put the pin into high impedence (release the line). Apparently it never does this, so the CEI circuit isn't working.
This appears to be okay on older PSX units, but not on the last revision.

You would have to fix this in the modchip code. As far as I know, it was never released.

Alternatively, use a different modchip code.

 

I wouldn't know how to fix it but you can easily get the code for it using a disassembler such as PIC-Disasm.

 

Thanks rama, that's probably what's happening.
There's nothing else to choose from as far as I know regarding different PIC codes. Direct booting of US/JP games is an essential feature that a chip has to have imho.

Is PSNee worth a try with the PM-41(2) boards?
Although the ATMega boards seem way to big to neatly install them in a PSone.

 

May get away with using a resistor on the line.

If you want to sell me just the console of this revision - id have a look at fixing the issue.

 

You can install PsNee and it will fix the issue. There's just enough space if you're careful.
This is on the earlier revision, with even less space available:


Might want to remove the reset button on the Pro Micro.

 

I have to say I find the power connection a bit worrying - it's wired directly to the power jack, so it's going to be running the PIC from about 7.5V - this is well outside the 3.0 to 5.5V recommended operating range and even exceeds the 7.0V absolute maximum rating.

 

Pretty sure thats the ground, not vcc.

 

Yeah, you're quite right - I didn't notice the chip was upside down...

 

But there's my old pet peeve in it: No bypass capacitors! None of the old chips ever have a proper bypass cap!