Hi all.
Okay ive not put this in general chat this time as its a repair rather than a lost cause
A600 (A300 Board from Taj) (A600 case from Pinkstabbyone)
*************************
The A300 (june bug)
The A300 was the first rev of the A600 board now there are some differences. The main one (to me) is that the PCB solder pads are the same size as the the caps that fit on them, this means a capacitor will almost completely cover the solder pad when the cap is fitted, making soldering more difficult than it usually is but with patience it can be done - and a small soldering iron.
Also the A300 board has an extra IC that the rev 1.5 does not , i don't know what it does and it doesn't concern me one jot as it works
************************
Faults - Leaking SMD caps / Grey screen for 2 to 3 mins / slow floppy read / slow machine speed.
Fault finding..
Well the caps were leaking, some not bad but some had leaked in a 20mm area from the cap..so replace the caps with a miniature hot air (butane) torch - kind of like a pencil sized torch thingy.
So heat the caps one by one - all the same size and type first , just so i didnt get mixed up
After this i cleaned the pads and re fluxed adn soldered a little to shine the pad up and make it look pretty. Too much heat will lift a pad so be quick!.
Okay after 20 mins or so all caps are changed except 2 (Audio) buggers to get at - i may do them later.
TEST TIME 1 .. power up and the A600 sits at the grey screen for 10 mins ..no go!!
WHAT?
okay further examination reveals that the CIA IC's can cause problems..so lets take a peek - no damage , no solder breaks?
Lets re solder the CIA soldered legs anyway ..a tiny drop of flux and a tiny bit of solder on each leg...10 mins later
TEST TIME 2 ...power on!
mmm grey screen but only for 20 secs or so then the ROM and floppy logo appear ...so we are getting better but the animation is slow and jerky.
So i re soldered the pins on some more IC's , washed the board in warm soapy water to remove any flux or solder drops etc..
leave to dry , blow dry with compressor and i placed it in a warm (not hot) oven for half an hour.
TEST TIME 3
BINGO !
grey screen for 20 secs (hard drive spin up time - if it had one)
then purple logo with a smooth animation!!!! yay
test time - sysinfo shows full speed !! and my A1000 demo disk shows the Amiga logo spinning without hesitation unlike yesterday!
So all in all a job well done.
A list of parts to follow and items used.
*******
im leaving the RF unit out - i dont think i'll ever use it
*******
PARTS
47uf 16v SMD
470 uf 16v thru hole
10uf 25v SMD
100uf 25v SMD
Mini hot air torch to remove old caps
https://www.amibay.com/showthread.php?t=17778 Previous thread
http://www.youtube.com/watch?v=QRR7fmqOE9M test of A600 speed after repair
Okay ive not put this in general chat this time as its a repair rather than a lost cause
A600 (A300 Board from Taj) (A600 case from Pinkstabbyone)
*************************
The A300 (june bug)
The A300 was the first rev of the A600 board now there are some differences. The main one (to me) is that the PCB solder pads are the same size as the the caps that fit on them, this means a capacitor will almost completely cover the solder pad when the cap is fitted, making soldering more difficult than it usually is but with patience it can be done - and a small soldering iron.
Also the A300 board has an extra IC that the rev 1.5 does not , i don't know what it does and it doesn't concern me one jot as it works
************************
Faults - Leaking SMD caps / Grey screen for 2 to 3 mins / slow floppy read / slow machine speed.
Fault finding..
Well the caps were leaking, some not bad but some had leaked in a 20mm area from the cap..so replace the caps with a miniature hot air (butane) torch - kind of like a pencil sized torch thingy.
So heat the caps one by one - all the same size and type first , just so i didnt get mixed up
After this i cleaned the pads and re fluxed adn soldered a little to shine the pad up and make it look pretty. Too much heat will lift a pad so be quick!.
Okay after 20 mins or so all caps are changed except 2 (Audio) buggers to get at - i may do them later.
TEST TIME 1 .. power up and the A600 sits at the grey screen for 10 mins ..no go!!
WHAT?
okay further examination reveals that the CIA IC's can cause problems..so lets take a peek - no damage , no solder breaks?
Lets re solder the CIA soldered legs anyway ..a tiny drop of flux and a tiny bit of solder on each leg...10 mins later
TEST TIME 2 ...power on!
mmm grey screen but only for 20 secs or so then the ROM and floppy logo appear ...so we are getting better but the animation is slow and jerky.
So i re soldered the pins on some more IC's , washed the board in warm soapy water to remove any flux or solder drops etc..
leave to dry , blow dry with compressor and i placed it in a warm (not hot) oven for half an hour.
TEST TIME 3
BINGO !
grey screen for 20 secs (hard drive spin up time - if it had one)
then purple logo with a smooth animation!!!! yay
test time - sysinfo shows full speed !! and my A1000 demo disk shows the Amiga logo spinning without hesitation unlike yesterday!
So all in all a job well done.
A list of parts to follow and items used.
*******
im leaving the RF unit out - i dont think i'll ever use it
*******
PARTS
47uf 16v SMD
470 uf 16v thru hole
10uf 25v SMD
100uf 25v SMD
Mini hot air torch to remove old caps
https://www.amibay.com/showthread.php?t=17778 Previous thread
http://www.youtube.com/watch?v=QRR7fmqOE9M test of A600 speed after repair
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