A608, 8Mb fast RAM for A600

[orange]

I finally got the A608, but it needs soldering. its a 4Mb version (though PCB says 8Mb). I never soldered SMD before, and manuals on google say there are two ways: with ordinary soldering wire or with paste.
soldering paste is quite expensive, is it absolutely necessary for that large socket?
is there any tutorial on assembling A608? (which components should go first?)

[alexh]

I take it that it is the 2007 version?

[orange]

yes, 2007 is printed on PCB

[cpiac64]

for ic 16 pin use iron max 25watt with fine tip, for memory and socket use desoldering braid

p.s.
i need a circuit not schematics, were i find and many €?

[orange]

i don't have schematics or any manual. where is the pin1 on PCB for SMD socket? which two RAM sockets should be left empty? why is 8Mb printed on PCB if its 4Mb version?

[fitzsteve]

Originally Posted by orange

why is 8Mb printed on PCB if its 4Mb version?

Becuase the same PCB is used for both versions, does it have 2 or 4 Ram chips? 2 chips = 4mb and 4 chips = 8mb

Even if you solder on the extra Ram you'll need the firmware for 8mb as its different, I had one with the full 8mb but only 4mb was showing as it had the 4mb firmware.

Also if you're not aware if you upgrade to 8mb you wont be able to use the PCMCIA port with the Ram in place.

Steve.

[cpiac64]

you find photo and schematics here http://nedopc.com/lvd/Projects/

[orange]

ok it says to solder two right chips, are those the ones closest to 10pin IDC connector?
i'd like the RAM chips to be socketed, would that work? (is there enough room for sockets when fitting in a600?)

[cpiac64]

10 pin idc connector is for programming altera chip

the ram is possible to sockets, some old vga have ram socket

[orange]

d-oh..
well I put the two RAM chips close to IDC, if that's wrong space I'll bin the whole damn thing.

where to put two larger capacitors (10uF)? according to photo they are soldered in a very 'unconventional' way. but my PCB has no space for soldering it that way. so should I just scrape off the lacquer insulation?

man, soldering the two RAM chips was tedious. I must have been doing it wrong way. hopefully intense heat hasn't destroyed them. I also "lifted" one track


I know that some vga cards have sockets. but they all seem to use 40pin (and we need 42pin here)

I also presumed idc is for programming, I mentioned it just to help identify ram chips.

[orange]

what a disappointment.. after all hard work, it seems CPU is just to small for A608. it simply isn't fixed at all, doesn't stay put.
also there is a large rectangular capacitor on motherboard that could short something.

bah

[cpiac64]

insert a photo of your work

[orange]

yeah well, I now know why he took photo of socket:
" The socked used is SMD and therefore low-profile. Thus you should solder
it raised over PCB and with some angle to it, as it can be seen on the
photos. The idea is to allow for the socket to fit firmly over the CPU
while not permitting physical contact with the Amiga motherboard by far
board edges. "

oh well

[alexh]

I think the mechanical problems you're seeing is why LordV made the 2008 version of the PCB.

[cpiac64]

i need only pcb, is possible ?

[orange]

@alexh
yeah I figured that out but too late.
so, I'll try desoldering the socket and soldering new one.

@cpiac
sorry, I don't wanna sell this after all the work. anyway you're better off with 2008 ver.

[orange]

could someone convert a600_8mb.pcb to PNG or similar bitmap format?

[cpiac64]

in the packet a600_8.zip the photo 5 and 6 are the pcb with components and the schematics are in png pdf sch pcb

[orange]

um, yes, but I want picture without components.

[cpiac64]

please, speack your problem.