5 boards to have a crack at
- Thread starter falen5
- Start date
All the socketed chips nearby. Out of all the SE/30 boards I had rebuilt, I have seen ONE case where the PAL/GALs were bad. it was causing the analog board to scream bloody murder. Replaced em, came back to life.
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heres what I did tonight - took off UE8 and UC8 ( to find the via for one of the pins) - this exposed all the first via's , along the trace , to all the missing pads left
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got smaller wire
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finished it up ( no picture, time!) - but its still the same
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will put up more pics tomorow
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got smaller wire
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finished it up ( no picture, time!) - but its still the same
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will put up more pics tomorow
Techknight - went to swap out the PALS only to find they are all soldered into the board. Swapped out the video rom - still no joy.
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heres where it is at now.
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Id better get this going soon because the more I go at it the weaker all the connections, pads, traces are getting.
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I have metered out the UE8 with my good board and it checks out...cleaned the boards both sides........I just cant find the fault...........it has to be something stupid.
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heres where it is at now.
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Id better get this going soon because the more I go at it the weaker all the connections, pads, traces are getting.
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I have metered out the UE8 with my good board and it checks out...cleaned the boards both sides........I just cant find the fault...........it has to be something stupid.
somebody gave this description in another post of same problem
"the Vertical Sweep IC at U2 (TDA1170A, 12-pin)"
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what chip is that?..........I cant see a 12 pin chip on the se/30 board anywhere!............is this chip on the analog board?
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I have metered out all the Ux8 chips and compared them to a good board. EVERY PIN IS CORRECT
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is there anything else that's would cause the horizontal line.
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would it be worth metering out all the pals
"the Vertical Sweep IC at U2 (TDA1170A, 12-pin)"
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what chip is that?..........I cant see a 12 pin chip on the se/30 board anywhere!............is this chip on the analog board?
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I have metered out all the Ux8 chips and compared them to a good board. EVERY PIN IS CORRECT
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is there anything else that's would cause the horizontal line.
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would it be worth metering out all the pals
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thanks 360alaska.
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the analog board is good. When I swap in my good board display is perfect..............so its this darn motherboard.
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I just cant find the problem and I cant hot air gun chips off anymore, the pads will all come off if I keep swapping chips
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have to go on the assumption the chips are good
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ah well..........off to a gig..........will spend hours staring at this thing later
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the analog board is good. When I swap in my good board display is perfect..............so its this darn motherboard.
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I just cant find the problem and I cant hot air gun chips off anymore, the pads will all come off if I keep swapping chips
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have to go on the assumption the chips are good
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ah well..........off to a gig..........will spend hours staring at this thing later
Well you need to look at the schematic. where is the vertical signal generated? the PALs I believe.
Even though they are soldered on, I would replace the one that is directly responsible for generating the vertical sweep drive.
Messing with UD8/UC8, etc all day isnt going to fix this problem I dont believe.
Even though they are soldered on, I would replace the one that is directly responsible for generating the vertical sweep drive.
Messing with UD8/UC8, etc all day isnt going to fix this problem I dont believe.
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Alot of those suggestions come from here: http://www.biwa.ne.jp/~shamada/fullmac/repairEng.html
But of course, you know you analog board is good... Unless that board has a short somewhere that damaged U2, Unlikely though...
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http://museum.dyne.org/gallery/apple/stuff/mac/andreas.kann/schemat.html
maybe this graphic i made will help you?
maybe this graphic i made will help you?
thanks uni - I looked at the drawing and understood nothing............then again im drunk as a lord - weh hey!
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to be honest ive got to the stage where I must understand what is actually going on , on the board - what ALL the chips do etc etc
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this is becoming an obsession.......just have to understand the board logic, use it to understand a problem, and again use it to find and fix the bas%$£d of a problem
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It kills me not having the knowledge I need to understand this
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off to utube for tutorials............god help me
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thanks again all
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to be honest ive got to the stage where I must understand what is actually going on , on the board - what ALL the chips do etc etc
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this is becoming an obsession.......just have to understand the board logic, use it to understand a problem, and again use it to find and fix the bas%$£d of a problem
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It kills me not having the knowledge I need to understand this
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off to utube for tutorials............god help me
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thanks again all
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blank video.
It looks like now the SWIM chip has problems, or the floppy drive is bad? It keeps flashing an X on the disk icon on the boot screen.
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