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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Fri Feb 13, 2009 2:49 pm Post subject: |
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| zGman wrote: | ""Or have a chip and the software designed, based off the original schematic and function of the circuit.........Did someone say 10's of thousands????????????????????""
From the service manual I have seen this chip is just a "black hole" - the page where it should
be is 'missing' (eg. simply not there), and there are no pinouts - and no way to trace the functions
in the schematic....
Hope you guys can find some info -
G |
Not sure what service manual your looking at but in mine I can tell you where every pin (that is used) goes to. It's not all done on 1 page, but using multiple pages...... 
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Fri Feb 13, 2009 3:11 pm Post subject: |
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You know John, the more I look over these schematics, its got me wondering. The low level write on ic 421 is tied in with the Dallas and various ram devices. I'm sure the Dallas dumps the registration data to ic421 on initialization. The high level write is tied in from the main cpu and to other port assigned chips besides ic421. I'm wondering if maybe ic421 is not preprogrammed but programmed during operation by the main cpu. That way pin assignment could be changed during operation if need be. Wadda ya thing??????????? 
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AnalogRocks
Forum Moderator
Joined: 08 Mar 2006
Posts: 26706
Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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| Posted: Fri Feb 13, 2009 4:43 pm Post subject: |
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Now that IS interesting Mac. If that's true then all you would need to do is make a work a-like and let the Dallas dump the data to the chip on start up no? ( I know making one is no small task )
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Fri Feb 13, 2009 6:15 pm Post subject: |
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| AnalogRocks wrote: | | Now that IS interesting Mac. If that's true then all you would need to do is make a work a-like and let the Dallas dump the data to the chip on start up no? ( I know making one is no small task ) |
Unfortunately there is a lot more going on in that chip then just the registration data. My thoughts were, if this dac controller had its function programming at manufacture, then why would it need a high level write. Once the registration data was written to the chip, it would already know what to do with it. There are many more sophisticated chips out there that dont require a high level write. Just a basic data right. The programming logic is already in there.
But if the high level write was the programming data then it would be an advantage. It would mean there isn't programming data for this chip out there somewhere that we're trying to locate.
The chip isn't identified on the schematics as a PDL yet there are other chips on there that are. Of course this is not a firm assumption.
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jask
Joined: 17 Mar 2006
Posts: 10187
Location: kamloops BC
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| Posted: Sat Feb 14, 2009 7:58 am Post subject: |
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| macgyver655 wrote: |
The chip isn't identified on the schematics as a PDL yet there are other chips on there that are. Of course this is not a firm assumption. |
To a Japanese EE it would be!! 
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richardc
Joined: 13 Feb 2008
Posts: 32
Location: Australia
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| Posted: Sun Feb 15, 2009 8:05 am Post subject: Heat |
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Hi Guys
As you may or may not know, I have a G90 which is the best projector that I have ever had.
(D50/G70/and now G90)
I have been working as an Electronic Tech for most of my life (now 62).
Component level pcb repairs, in the Newspaper industry which covers quite a wide variety of devices etc.
The biggest killer of semiconductors is heat heat and more heat.
Whether it be caused by poor design, power areas with poor ventilation or just ageing of capacitors in power supplies which go leaky, which then put higher ripple voltage on low voltage rails and that stresses semiconductors.
But thats in extreme cases, I believe that the G90 is very well designed maybe even over engineered.
And being over engineered I would bet that the IC in question is not the only chip thats not available.
Curt of the 6 G90's that you know of, have any had the fan mod done, what I am getting at is we should keep our precious G90's as cool as possible.
Thats the reason that each fan is monitored for rotation, you can't afford to have a fan stopped.
Regularly cleaning of fan ares in particular would be good house keeping.
Sony put those fans in to move a lot of air for a reason, to cool the beast.
Of the 6 sets that have failed has the power supply outputs been scoped for noise / ripple etc, are some of the outputs slightly high.
Another concern about Heat is with MP's mod 1080p 72hz when this mod is put in we will indeed need all the cooling that we can get the Horizontal power amps will be stressed to max they weren't designed to run like this.
Any thoughts
Regards
Richard
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Sun Feb 15, 2009 3:27 pm Post subject: |
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I'm right with you Richard, which is why I cringe when people do fan mods that are untested.
Due to the location of the Ya board, and hte fact that the chip itself has no outside contact with other modules in the set (inputs and outputs are buffered), and the G90 isn't known for random HV arcing, I am leaning more towards a poorly designed chip. There's piles of other chips connected to the power supply on that board, why only would that one fail?
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RogueChili
Joined: 31 Mar 2008
Posts: 162
Location: Westfield, MA
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| Posted: Sun Feb 15, 2009 4:46 pm Post subject: |
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From my observations, D-RES and M1-M5 lines are not I.C. buffered. It appears they exit the board via series resistor. According to the block diagram these lines go to the DE board and CN535 via mother boards. Any chance CN535 is exposed to potential for static or hi voltage arcing?
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Sun Feb 15, 2009 7:16 pm Post subject: |
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Who here besides John has verified an ic421 failure? Also, I remember reading John's procedure of diagnosing his ic421 but cant remember where its at. I'd like to read it again if anyone knows where its at.
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kschmit2
Joined: 09 Mar 2006
Posts: 1141
Location: Heidelberg, Germany
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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Tom.W
Joined: 09 Mar 2006
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Sun Feb 15, 2009 10:15 pm Post subject: |
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Thanks guys..... I'll have to do some reading later.....
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Mon Feb 16, 2009 12:10 am Post subject: |
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Ok, so who all has a G90 that ic421 is believed to be the problem?
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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Mon Feb 16, 2009 12:45 am Post subject: |
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To bad you can't just X-ray the friggin thing to see what's inside.
I have not been keeping up with this thread. Has anyone tried a different approach by e-mailing support from some of Sony's known chip suppliers to see if any of them recognise the number?
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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Mon Feb 16, 2009 12:45 am Post subject: |
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To bad you can't just X-ray the friggin thing to see what's inside.
I have not been keeping up with this thread. Has anyone tried a different approach by e-mailing support from some of Sony's known chip suppliers to see if any of them recognise the number?
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Mon Feb 16, 2009 3:15 am Post subject: |
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Datasheets are usually written by the chip manufacturer. Also the basic part number CXD is usually a Sony specific number. This number along with the datasheet that was acquired, showing Sony's copyright pretty much indicates Sony as being the manufacturer. I wouldn't be at all surprised if Sony doesn't have their own chip manufacturing facility. The only small hint of a different manufacturer is the reference to LSI which could be a chip manufacturer or it could just be the type of chip that it is. The definition of LSI when referencing logic chips is Large Scale Integration which means it contains 3,000 to 100,000 transistors on 1 chip. So its like trying to find a needle in a hay stack to find someone who may have some specific knowledge about this chip and who really makes it. Plus these people may only speak Japanese so I wouldn't be able to communicate with them anyways. Hopefully John's contact will reveal something.
I didnt try to translate the datasheet because I believe its the same as what is stated in English. Any one that wants to verify can go right ahead.
I have some other thoughts about this but I want to wait until John is back on board. I talked to him via PM and he's tied up in another project right now and as soon as he's done he'll respond in the thread.
Curt, do you have any YA boards needing the ic421 chip besides Haydns?
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Mon Feb 16, 2009 3:50 am Post subject: |
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After looking at that datasheet again I noticed on the first page in the upper right corner it has outside destination then something under it in Japanese. If someone can translate that it might have something.
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kschmit2
Joined: 09 Mar 2006
Posts: 1141
Location: Heidelberg, Germany
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| Posted: Mon Feb 16, 2009 8:03 am Post subject: |
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| macgyver655 wrote: | | After looking at that datasheet again I noticed on the first page in the upper right corner it has outside destination then something under it in Japanese. If someone can translate that it might have something. |
that's probably just the people that have to give authorization when the document is handed to people outside the G90 project, i.e. either other Sony departments, or - as in our case - parties outside Sony.
After all it is labeled "internal distribution only", and the stuff on the top right seems to lay out the details for exceptions from that rule.
Btw,
there's an internal specification number on the datasheet that may also prove useful:
SD-S 98/02 B
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