Adjust laser height on v3 Auto adjusting cog style DVD drive

[shadovraven]

Tried adjusting the lens angle , opening it up and cleaning it , no luck .
I've been reading about adjusting the laser pot . Anyone knows which one is the DVD pot in the pic ? Also, what is Romeo mod , ever heard of that ? They say 50004 is a "time bomb" without it . I guess my console is an exploded bomb anyway )

"Romeo mod is when you lift pin 17 of the LA chip and connect it to a 5V point instead of the 12V it's connected to. There's an awful bug with the LA chip that makes it burn the laser coils when using less than perfect media on a V9/V10. This mod helps prevent it."

I hope it does make it clear, about adjusting the laser pot, look here:

http://www.google.pl/imgres?imgurl=h...1t:429,r:2,s:0

[flo]

So i adjust the pot clockwise or counter ? 1 mm each spin ? Do i really have to measure the ohms ? I don't have any tool for that . Also I really messed up the 2 litlle wheels ,don't know which was their initial position , i'm thinking in the middle is ok ?

[noetikos]

*the fins that surround the LA 6508 chip are also fewer and smaller than the v7 BAxxx chip which does a much poorer job of cooling the chip at higher temperatures (heating is also one other major vulnerability of that cheap & cursed chip).

[l_oliveira]

The bug is not on the LA chip. It's on the Mechanics controller (MECHACON) firmware.

It controls the tracking coils through an interrupt routine or something similar and if the MECHACON freezes, the PS2 stops responding to the reset button, keeps the laser and focus/tracking coils on at maximum current. It just happens to be the tracking coils which fry first.

On some rare cases, both coils burn. And on some other cases (related to bad install of modchips) the DVD or CD laser emitter burns out.

It is actually designed to burn/fail that way. Because of possible fire hazards they asked Sanyo to add fuses on the outputs of the LA6507 chip.

The older ROHM chips used on earlier models (BA5810/5815) suffer of short circuit/major failure when such a crash happens, causing the 2amp fuse to blow and the console to stop displaying the screen (MECHACON detects that the console has a fault on the servo driver and does not reply to the ready request from the CPU/BIOS so the screen remains black and the system halts.)

[flo]

So i may be spinning that DVD knob for nothing ? The CD's work great , is it possible the DVD coil is burned because of this bug ? Console is not modded .

[l_oliveira]

The coils should measure around 5 ohms each.

To test disconnect the flat cable that goes to the main board and remove the optical pickup from the console.


Then you *GENTLY* remove the top plastic cover to expose the lens assembly.

There you will see the 4 solders that connect the lens coils to the main flexible board of the laser pickup.

The two on the top (lens facing up) are for the tracking and the two at the bottom are for the focus. The lens coils should measure aproximately 4.5 to 5 ohms each (use an ohm meter at the lowest scale it has, test it like if you were testing a car speaker).

Focus make the lens go up and down, tracking make the lens go left and right.
Without tracking the lens can't find the disc grooves. DVD grooves ate thinner than the ones on CDs and if the tracking coils are damaged/changed or misaligned (due to mechanical shock like dropping the console), of course the laser will have trouble reading DVD discs even if it still can read CDs.

[noetikos]

The bug is not on the LA chip. It's on the Mechanics controller (MECHACON) firmware.

It controls the tracking coils through an interrupt routine or something similar and if the MECHACON freezes, the PS2 stops responding to the reset button, keeps the laser and focus/tracking coils on at maximum current. It just happens to be the tracking coils which fry first.

hypothetically speaking, the romeo mod is applied as a precaution (the particular console hasn't suffered any damages yet) to prevent any damage to the laser as a result of the bugged LA chip.

via the romeo mod the laser and coils undergo a 5v current rather than a 12v (maximum) current. so if the mechacon fw (firmware) for some reason causes the mechacon routine tasks to crash or halt then the laser & coils will not experience substantial damage? the ongoing 12v current is what fries either the coils or laser emitter. if the 5v mod prevents damage to the laser then it means that the mechacon can crash once again and yet not pose anymore damage?

i'm just trying to understand what you're saying dude

[l_oliveira]

Romeo mod does nothing but make it last longer in a fault condition (means there's enough time for you to turn the power off if it freezes, like when you're playing a game and FMV freezes)

Edit: Errors on the sub channels are quite likely to crash the mechacon. There is a chance even pressed discs have some errors, but SONY engineers were then aware that a lot of recorders do not generate 100% proper signals or that media can degrade over time making such code have bit errors. A BAD media like CMC or Princo is more likely to cause a mechacon crash than a Tayo Yuden (T0/TY) or Mitsubishi (MCC) disc.

The only way to make sure of not having issues is not using DVDR at all. Even some shoddy quality pressed discs can cause the mecha to crash. Hence the lawsuits we saw a few years ago in the USA. SONY had to "fix" it but they decided to keep the bug on the firmware while they added an mechanism which shuts down the servo circuits. It still let the drive crash so a eventual pirated game one would be playing is still going to crash, causing inconvenience. Why they would want to help people on playing copied discs ? lol

FMCB and ESR removes another crashing factor of the equation (modchips) which alleviate the situation a little bit.


Again, at a lower current, the coils will still burn. The coils are not designed to receive current all the time, but to receive pulses of current to allow them to align with the grooves/disc surface. Even the weight of the lens are considered when the mechacon is calculating the amount of power it has to apply the coils to move them a certain distance. When you use lens changer, you're changing that "weight adjust" as obviously the Sanyo HD-7 laser pickup has heavier lens and require more powerful driving than the SONY KSS-400C pickup. Hence the louder "clicks" you hear on a PS2 programmed for HD-7 when you have a 400C fitted.

This "fried coils syndrome" is not a issue only seen on PS2 consoles... Back on the early days of CDs, the famous Yamaha CDR-400 CD recorder had a bad firmware bug on early versions, which would fry the tracking/focusing coils on any drive that was left on for a long time without a disc inside. Recorders suffering of that fault would have an audible high frequency noise coming from the optical pickup after a disc were removed from it.