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PS2 Comsoft v4 Fix Confirmed.

HaloSlayer255

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Hello all,

In reference to a previous thread I posted in: https://www.obscuregamers.com/threads/ps2-matrix-pic-fix-hex.1825/

Well after a lot of trial and error and with life getting in the way. I was able to finally find the mechacon pulse signal referenced as Point K on the Comsoft v4 slim laserfix. This fix is now able to be used for GH-023 and GH-026 boards. Kel was also able to use the subzero laserfix on these consoles as well, unfortunately I don't have access to his pics and he's not feeling so well atm.

As a note however, does anyone have a good looking service manual for the GH-026 board? I have one but it doesn't clearly show all the components that will need soldering to. All I have are pictures with my modchip install on them and it kinda obscures point K. Resistor is marked value 103, in what should be the GH-026 service schematic R609.

That being said link is here: http://www.mediafire.com/file/68qr45psuwgxwfb/Comsoft+v4+Files+for+v9-v12+PS2.zip/file

This zip file has HEIC images for the v10 install just as a heads up. Folder size is 78.22 Megabytes.

It also contains every single file used for the creation of this board on OSHPark (or use this link: https://oshpark.com/shared_projects/3D5p1xeY )

As well as the service manuals for GH-023 (v9), GH026 (v10) (needs better pcb layout view), and the GH-035 (v12) PS2 consoles. The original creator of the comsoft fix video is also in here showing their PS2 slim working with this fix. Will probably take a video of mine soon enough.

I'm sure that this is everything needed to utilize this laserfix but if something else is needed please reply.

Hope this is helpful and lets wish Kel good health,
HaloSlayer255
 

HaloSlayer255

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Just tried this again on a GH-023. Fan spins when master switch is turned on for the power supply, consoles lights amber/green and eject blue light do not turn on.

Soldered directly to pin 78, pin 77, and the test pad referenced in the schematics.

This fix seems to only cooperate with the v10 Gh-026 boards.

Could it be something was changed with the mechacon bga chip?

---Edit---
On the GH-026 board, dvds still boot, but booting a ps1 cd based game or ps1 game causes the system to shutdown immediately after the tray closes.
---End edit---
 
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kel

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Going to make a start on this post while I feel up to it.

I installed the comsoft fix on a v9 PS2 a couple of years ago and it seemed to work without any issues. It was just temporary because my preferred fix was the subzero fix but I was having issues with the subzero fix on the v9 console at the time and wanted to just check if the comfost fix worked instead. I then found a workaround for the subzero issue and reinstalled that instead. I did take a test reading for the comsoft fix on the v9 at the time with an oscilloscope and it did shut down the laser coil within 50ms.

I'm not sure why it hasn't worked out as well on Haloslayer's PS2s as it seemed to do on mine and unfortunately I have not been able to delve back into the subject and help get to the bottom of the problem due to being unwell this past year.

Anyway I'm adding some images to this thread regarding mainly the subzero install for Haloslayer to try as an alternative and also anyone else that may be able to make use of them. These images were from 2 years ago and seem to be missing some diagrams or maybe I just never got around to making them so I will try to add what is missing if and when feel well enough but hopefully there will be enough there to get anyone going and prove that it works. This may take a day or so of editing to add the images and descriptions as I feel pretty drained at the moment and would prefer to take my time. I'll mention at the bottom of the post when everything that I have is all there and what is missing.

Comsoft fix installed in v9 PS2.

The yellow channel #1 is the INT signal, The blue channel #2 is the tracking coil and the purple channel #3 is the mute signal on of the LA6508H motor driver.

As can be seen from the readings when the INT signal (yellow) drops low, within 50.8ms the mute signal (purple) for the LA6508H drops low which then mutes the tracking coil (blue). The Comsoft fix also turns the PS2 into standby shortly after IIRC but I was only testing that the tracking coils shut down so I didn't add that signal to the test, besides holding 3 probes at the same time was difficult enough :)

PS2_v9_Comsoft_Fix_Ch1=INT_Ch2=T-Coil_Ch3=Mute#3.png


Subzero fix installed in v9 PS2.

Image is of a 0603 1uf ceramic capacitor tombstoned on the 5v trace, then on top of the capacitor a diode going to the INT signal and a resistor going to the lifted pin on the LA6508H and then from there another diode going to a test pad which is connected to where the lifted leg came form. It's hard to see the tombstoned 0603 cap in the image but just for reference it's above the large 220ohm resistors to the right and under the blob of solder where the heatshinked diode and resistor meet. It will make more sense on the diagram in the next picture. It doesn't need to be a 0603 capacitor tombstoned like that. You're probably better off for your own sanity using a normal radial ceramic cap as long as the terminals are insulated. I just wanted to push myself and see if I could managed to do it with a 0603 cap without driving myself insane and throwing the PS2 out of the window :)

PS2_v9_Subzero.jpg

Below is a diagram that I did a couple of years ago for the subzero fix on the v9 PS2 with component values and orientation. Originally there were only 3 components for the subzero fix, a diode, resistor and capacitor which worked great on the v12 PS2 but for some reason when installed in the v9 PS2 the disc tray would refuse to eject. It worked out that the v9 would not eject the tray unless the LA6508H was muted first which would not be a problem normally as the PS2 would pull the mute pin low when the eject button was pressed. The problem is that we have now lifted the mute pin and connected it to the INT signal which was keeping it high but connecting a diode from the mute pin back to the original mute signal solved the issue anyway and allowed the original mute signal to pull it low if need be. I suppose it didn't matter so much on the v12 as the disc lid was just held by a catch and would be manually opened but now come to think of it maybe it would be wise to do the same for the v12 PS2 so that the motor driver IC is muted whenever the disc lid is opened.

The Comsoft mod didn't have this issue as it connects in between the original mute signal with a pull down resistor IIRC. Looking back now maybe I should have just done it with a pull down resistor but the diode seemed to do the job just as good. Feel free to try replacing the diode at the bottom of the diagram with a 10k pull down resistor which seems to be the case on the comsoft fix as I don't actually know if using a diode is ideal, it just worked at the time so I went with it.

Subzero-fix v9.png
The image below is the measurement of the Subzero fix. Same as before, the yellow channel #1 is the INT signal, The blue channel #2 is the tracking coil and the purple channel #3 is the mute signal on the LA6508H motor driver.

When the INT signal (yellow) goes low the capacitor on the subzero fix starts to discharge which is shown by the mute signal (purple). Once the mute signal (purple) reaches 1.5v or below, which seems to be the threshold for the mute pin on the LA6508H it then shuts down the tracking coil (blue). In this case it took 44ms for the tracking coil to start shutting down which is not a big difference from the Comsoft fix. This value can easily be changed though by changing the value of the resistor or capacitor of the subzero fix but I was happy with 44ms so didn't bother in this case.

PS2_v9_Subzero_Fix_Ch1=INT_Ch2=T-Coil_Ch3=Mute_1uf#1.png

Subzero fix installed in v12 PS2.

Same as on the v9 with the tombstoned 0603 capacitor but this time it was connected to the 8v trace, same as the original subzero PCB did. On top of the capacitor is the resistor going to a via that connects to the mute pin of the RS2004FS and also a diode going to a via connected to the INT signal. I didn't need the extra diode on the v12 as mentioned before but in hindsight it may be worth adding one so that the RS2004FS is muted when the disc tray is opened.

This install is a bit more difficult than the one on the v9 due to the small vias that you have to solder to and also a small trace that needs to be cut on the v12 motherboard. As before with the v9 install you can make things easier by using a radial ceramic capacitor. Also there is an alternate point for the INT signal but IIRC it is on one end of a 0402 resistor so still not much easier to solder to than a via anyway. Be very careful if soldering the resistor and diode to the vias as done in the image below because if you solder the via end first then all it takes is the slightest nudge and the via will rip right away from the board. Once it's all in place though it is a bit more sturdy. It would probably be safer to solder kynar wire between the components and the vias, don't say that I didn't warn you :) Feel free to probe the other side of the motherboard for more suitable alternate connection points. I didn't bother to check for any at the time.

The trace that needs to be cut is the one that comes from the via that the resistor is connected to. I need to make a diagram for this install so that it makes more sense...

PS_v12_Subzero#2.jpg
PS_v12_Subzero#2.jpg


...TBC
 
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HaloSlayer255

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Thank you for the reply kel,

Gonna try this out just need to order some of those resistors and diodes. That soldering looks very impressive, especially the la6508 leg.

Have a Merry Christmas and Happy New Year!

Stay warm and my continued prayers that you feel better.

Robert (HaloSlayer255)
 

kel

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Thanks for your support.

I hope that the subzero install goes well for you. If you want to test it then add a temporary switch between the INT signal and the diode and load a game. When you turn off the switch the game should stop loading, crash or freeze.

Merry Christmas and happy New year :)
 

xzerPL

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Thanks for your work! I will try check it out on my console.
 

foldor

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Hey, I recently added a Modbo to my v12 PS2 Slim, and I've been looking for a good laser fix solution. I've read up on Comsoft and Subzero, and I believe from what I've been reading Subzero is probably the best one to install, but I haven't been able to get a source on what components are needed and where for Subzero. Does anyone have a link for it?
 

xzerPL

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You need for ps2 slim:

-1uf ceramic capaticor
  • 33k Ohm resistor
  • 1x 1n4148 Zener diode (2x for fat)

Diagrams:
VYQV4Uw.jpg


And second one in better res (points K, L2, Vdc and you need to cut a track near L1 [after cuting it shouldn't be continuality between L1 nad L2)

oXpEhJT.jpg



I also highly recommend summ0ne fix:

kEf6io1.jpg


Install only Rst resistor (first from the top).
 
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