>I was wondering if someone might be able to come up with a permanent solution >...maybe there are some spare [VRAM] chips with longer pins
IIRC these are 256k x 4bit 80ns VRAMs. I have a number of these, types: OKI 514262-80Z and OKI 514252-80Z. There is a difference, IIRC, the first type has some sort of integrated unit that facilitates bit-blit and color fill operations, but as far as I remember, it is downwards compatible with the standard which should be the 514252. The Q40 doesnt use this unit anyway. I've got 16 of each, Q40 uses 8 - I have 8 brand new 514262s, the rest are recycled but with full length pins. I could probably be persuaded to part with them ;-) The problem with these is probably the typical problem with recycled chips in sockets - the pins are not cleaned from the remaining solder, they effectively become larger because of the extra solder plating. This puts extra strain on the spring loaded contacts in the socket. Couple that with thermal cycling, where parts dilate and then shrink back every time they go through a power on / power off cycle, and the socket becomes progressively looser, but the solder part of the pin gets 'worn down' as it is softer than the actual pin. The result is lack of contact - in some extreme cases chips have been known to pop out of sockets (This sometimes happens even on new chips with badly designed sockets). The result can sometimes be that even brand new chips will not fit any more - as the brand new ones will have pins that are too thin to make contact! If such a situation arises, the quick and easy solution is to carefully solder the chips into the sockets - chip by chip, so you can get at all the pins. In case of a chip failure, this will not make much of a difference - the socket failed in any case, so the only difference is wether there is a bad chip soldered into a bad socket, or it's only the bad socket - in either case the socket has to be desoldered, and thrown away, with or without the chip. As Tony well knows from superHermes, turned pins in professional sockets DO solder quite easily even from the wrong end ;-) Nasta
