The Matrix Team - V12 Dead Syndrome Fix V2.0
--------------------------------------------
UPDATE : November 24, 2004
--------------------------
Added hex file in INHEX8 for those programmers that don't support INHEX16.
Settings are included in the .hex file but can be set manually as
follows : IntRC oscillator, Internal MCLR, Watchdog timer ON.
Note : If you want to make sure that your pic was programmed correctly and
that the resistor value is low enough to turn off your pstwo you can do so
in the following way : Install the 12c508 as from the schematics but connect
pin 4 to GND instead of point K. The pstwo should turn on when pressing reset
and turn itself off after three seconds. If this happens you can be sure that
the 12c508 is working and that the resistor value chosen is correct.
Disconnect pin 4 from GND and connect it to point K on the diagrams and you
are set to go.
November 22, 2004
-----------------
Just a quick follow-up to our previous reports. A more in depth explanation
will follow later on but at this point we believe it's more important to
offer a quick fix for all those poor pstwos out there ;-)
Further analysis on several V12 has shown that in certain situations the
mechanics controller can fail while communicating with the dvd controller.
You can notice when this happens since the reset button, which is connected
to the mechanics controller, will stop responding and the only way to turn
off the machine is to unplug the power jack.
When the mechanics controller crashes, the dvd controller keeps sending
a pulse train to the tracking and focus drivers which results in a steady
voltage increase on both the tracking and the focus coils.
With the proposed diode fix, this increase is initially limited but if the
user leaves the crashed pstwo on for several seconds the output drivers
will eventually reach saturation and, if the RS2004FS thermal protection
doesn't kick in, the coils can burn from the increased current flowing.
As promised on our latest news, our proposed solution to this problem
consists in a simple 12c508 plus an additional resistor.
There are certainly other solutions to this problems (some of which are
currently being tested) which can offer a more general protection
to the coils by constantly monitoring the voltage applied to them.
However we felt that it was much more important to offer a cheap,
easy and fast fix instead of a more general one which would be outside
the reach of the general hobbyist.
In a few words : programming a 12c508 pic is something most people
with interest in electronics can easily do. The blank component is
very cheap (around 1 USD) and a programmer can be built or bought for
a few bucks if needed.
Further more, this simple fix has been proven to work an all occasions
during our tests, so it should already offer a very high protection.
We are releasing the pic hex file free (as in speech and as in beer
for all to use and experiment on. We are also releasing the gerber
files for two small PCBs : one can be used with only the pic and the
resistor, while the other has also space for 8 1n4148 smd diodes.
Do with those as you wish : make a few of them for you own use, or
build some more and offer them for sale (hopefully for a low price,
since all the research and development cost has been already done ;-).
The simple program to be burned inside the 12c508 will constantly
monitor the communication between the mechanics controller and
the dvd controller. As soon as it detects a crash in the communication
it will turn off the pstwo to avoid any possibile damage to the coils.
Important note : the resistor value (1500 Ohm) has been chosen as the
best value according to our tests.
If the value is less than 1000ohm the pstwo will stay in a permanent
reset state and not even the red led will turn on.
On the other end if the value is higher than 3300 ohms the pic will not
be able to turn off the pstwo when needed. This has been tested on
several machines with consistent behaviour.
However there might be other board revisions which might behave in
a different way (maybe because of a different reset controller IC used).
So if you experience problems with the 1500 Ohm resistor, you can probably
safely increase it to 2000/2200 ohms. Please, only experiment with
different values if you understand what has been said (or if you don't
care about running your pstwo without being sure that the coils protection
is working).
The usual installation care should be used when installing this fix.
Preferred position for placing the pic or the PCB is in the lower left
corner of the ps2 motherboard. Make sure that both a J and K wires run
parallel to the board and make them as short as possible.
Last words : this fix can be used with or without the diode fix.
The diode fix can certainly increase the life span of your lens, and
should provide you with more time to realize that your ps2 crashed and
turn off the main power, should the pic chip fail to work. This has
not happened once so far in our test, but as usual the real results
will come from the thousands of pstwos out there.
--------------------------------------------
UPDATE : November 24, 2004
--------------------------
Added hex file in INHEX8 for those programmers that don't support INHEX16.
Settings are included in the .hex file but can be set manually as
follows : IntRC oscillator, Internal MCLR, Watchdog timer ON.
Note : If you want to make sure that your pic was programmed correctly and
that the resistor value is low enough to turn off your pstwo you can do so
in the following way : Install the 12c508 as from the schematics but connect
pin 4 to GND instead of point K. The pstwo should turn on when pressing reset
and turn itself off after three seconds. If this happens you can be sure that
the 12c508 is working and that the resistor value chosen is correct.
Disconnect pin 4 from GND and connect it to point K on the diagrams and you
are set to go.
November 22, 2004
-----------------
Just a quick follow-up to our previous reports. A more in depth explanation
will follow later on but at this point we believe it's more important to
offer a quick fix for all those poor pstwos out there ;-)
Further analysis on several V12 has shown that in certain situations the
mechanics controller can fail while communicating with the dvd controller.
You can notice when this happens since the reset button, which is connected
to the mechanics controller, will stop responding and the only way to turn
off the machine is to unplug the power jack.
When the mechanics controller crashes, the dvd controller keeps sending
a pulse train to the tracking and focus drivers which results in a steady
voltage increase on both the tracking and the focus coils.
With the proposed diode fix, this increase is initially limited but if the
user leaves the crashed pstwo on for several seconds the output drivers
will eventually reach saturation and, if the RS2004FS thermal protection
doesn't kick in, the coils can burn from the increased current flowing.
As promised on our latest news, our proposed solution to this problem
consists in a simple 12c508 plus an additional resistor.
There are certainly other solutions to this problems (some of which are
currently being tested) which can offer a more general protection
to the coils by constantly monitoring the voltage applied to them.
However we felt that it was much more important to offer a cheap,
easy and fast fix instead of a more general one which would be outside
the reach of the general hobbyist.
In a few words : programming a 12c508 pic is something most people
with interest in electronics can easily do. The blank component is
very cheap (around 1 USD) and a programmer can be built or bought for
a few bucks if needed.
Further more, this simple fix has been proven to work an all occasions
during our tests, so it should already offer a very high protection.
We are releasing the pic hex file free (as in speech and as in beer
for all to use and experiment on. We are also releasing the gerber
files for two small PCBs : one can be used with only the pic and the
resistor, while the other has also space for 8 1n4148 smd diodes.
Do with those as you wish : make a few of them for you own use, or
build some more and offer them for sale (hopefully for a low price,
since all the research and development cost has been already done ;-).
The simple program to be burned inside the 12c508 will constantly
monitor the communication between the mechanics controller and
the dvd controller. As soon as it detects a crash in the communication
it will turn off the pstwo to avoid any possibile damage to the coils.
Important note : the resistor value (1500 Ohm) has been chosen as the
best value according to our tests.
If the value is less than 1000ohm the pstwo will stay in a permanent
reset state and not even the red led will turn on.
On the other end if the value is higher than 3300 ohms the pic will not
be able to turn off the pstwo when needed. This has been tested on
several machines with consistent behaviour.
However there might be other board revisions which might behave in
a different way (maybe because of a different reset controller IC used).
So if you experience problems with the 1500 Ohm resistor, you can probably
safely increase it to 2000/2200 ohms. Please, only experiment with
different values if you understand what has been said (or if you don't
care about running your pstwo without being sure that the coils protection
is working).
The usual installation care should be used when installing this fix.
Preferred position for placing the pic or the PCB is in the lower left
corner of the ps2 motherboard. Make sure that both a J and K wires run
parallel to the board and make them as short as possible.
Last words : this fix can be used with or without the diode fix.
The diode fix can certainly increase the life span of your lens, and
should provide you with more time to realize that your ps2 crashed and
turn off the main power, should the pic chip fail to work. This has
not happened once so far in our test, but as usual the real results
will come from the thousands of pstwos out there.
I was gonna say that. lol
