Sam,
Ouch! Tugging at my eyes to clear those good naturally rantings...:)
I used to fix quite few of them because I took few apart
and was told by a C64 vet who repairs and resells them in early days.
In C64 machines, buffers is not on Commodore's minds (saving $,
yes right!) so they blow up pretty easily by idiots resulting in lots
and lots of 6522 PIA ic swaps but that is not it for "dead" ones.
About the black boxes PSU, most of them are potted, ack! Better
snip off the power cable C64 side and wire up a new transformers that
is same ratings as the orignal or bit better than that and use one
regulator there, other two AC lines is used to power inside
rectifers/regulators/filter capacitors and multiple fuses! You have
to also open up the halves and check the voltage outputs after the
regulators and fuses, capacitors inside the c64. Better C64 power
bricks is not potted and is colored beige, they're easy to fix so
look for them instead.
The circit board is more of barebones worth of
interconnected chipsets and few TTL's, not that real problem there.
Fixed other C64 by replacing all 4164's, and a happy owner.
There IS a powerful tool that connects all the ports, cartidge
port and it takes over the C64 for diagnostics via the monitor.
Sorry, they're kinda not rarity. More like coachroaches everywhere
you go. I see them all the time, truly coachroaches that won't go
away! (as I type this, amid Sam's wails of frustration is heard.
Just imagining myself.)
About the drives, they do need cleaning and greasing to operate
properly, check the clocking. I fixed one because a sick crystal
blew out the IC in the little sheilding box. I think they did have
their own PSU inside that drive box? that was long ago. :))
The red led is controlled by cpu inside which is bit useful.
Also make sure the drive rpm is right, it does have belt driven
spindle.
For a moment, users still use them for some reasons...You may
remember that my friend burns his EEPROMs on C64 with a burner
cartidge for years and says it was well worthwhile investment and
paid him every time he uses it, it's already paid for long ago. (the
burner can burn anything up to 27256 types) Recently, he's digging
for it because this thing grew legs and got lost in his junk in order
to burn a new image into EEPROM IC. That's for fixing the 2 years
old Asus board branded PVI-486SP3 that lost it's rom memory for no
reason.
In a nutshell, check those DC voltages first. For grabled display
(aka checkerboard display) at startup often points to memory fault.
Also clean those edge contacts with strong alcohol, crunch socketed
chips in. Also C64 used RF sheilding with fingers that contacts the
IC's for heatsinking, put some fresh heatsink paste there if needed.
If some ports, keyboard, serial and I/O, funny sound, seems dead,
suspect 6522 PIA's Those MOS technology runs HOT like hot sunlit car
seats. (g) There was at least 3 generations of PCB boards in C64
lifetime designs, the last one was fewer chipsets and one big IC, all
in tiny board.
Very easy to open up that shells, needs to unsolder the RF tin pan
(Just tedious but easy to do in order to get at solder side if
needed. When soldering work, be easy on PCB, it is not very good to
heavy-handed tech.)
To summarize:
* Power problems - dead or flaky operation, check both inside C64 and
the power brick.
* blown PIA's (two of them) - C64 seems to work but certain
feature(s) is/are dead.
* memories - grabled or checkerboard.
>
> I have to get this off my chest.
>
> Commodore 64s have to be the god damn shittiest made computers ever. I
> had to test these 1571 drives that I sold someone and brought out 2 C64s
> I have in my garage and 2 power supplies because I know how notorious
> each part is for not working. I plug each in and niether work. I try
> the other p/s...same thing. I get ANOTHER p/s...both dead. I get yet
> ANOTHER power supply and 3 more C64 consoles I have. Of those 3, 2
> worked! Is this a shittily engineered system or what? What bad weed
> were these idiots who designed this smoking? I've never had such bad
> luck with any other system. Out of all the systems I've ever acquired,
> the commodores and their stupid prone-to-burning-out power supplies have
Actually, the design fault because the potting held in heat output
from the regulator inside and made it worse by the transformer.
If you are patient, chip at potting away until you get at the
regulator, replace it with bigger heatsink and find the fuse too if
needed.
> been the most likely to not work. I've gotten systems out of the rain
> that have been sitting in the elements for probably YEARS that have
> worked. But a C64? Hell no! Piece of crap!
PCB is PCB with chips and all get ruined if left out in elements.
>
> There must be some well-known fix for these idiotic things. I turn them
> on and get just a pure black screen. This is what happened to the first
> C64 I ever got from a friend 9 years ago. It just up and died on me all
> of a sudden one time when I was using it. Screen went black. There's
Looks like power loss somwhere in that one and blown fuse.
> got to be an easy way to fix these stupid things. Either that or there
> must be a well known joke passed around in commodore circles about how
> unreliable these junk heaps are. What a depressing hunk of crap.
Remember, we are supposed to fix those historic stuff not wasting
those little poor electrons that made up this letter?
To add, the worst machine to work on is old Toshibas, thousands of
screws and little parts, too short wires, etc and baddie of all,
pitiful few hd choices especially ones that uses regular IDE
hd...Mostly in early series before '91.
>
> Aye.
>
> Sam
> -------------------------------------------------------------------------------
> Computer Historian, Programmer, Musician, Philosopher, Athlete, Writer, Jackass
>
>
Jason D.
Received on Wed Jul 02 1997 - 22:34:55 BST
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