30 Apr
2013
30 Apr
'13
8:49 a.m.
Some of the electrolytic caps in the audio section are no doubt bad. I had
a similar no/low-sound on my IIci which went away after I recapped the
thing.
On Tue, Apr 30, 2013 at 8:14 AM, Liam Proven <lproven at gmail.com> wrote:
On 30 April 2013 05:43, Alexandre Souza
<alexandre.tabajara at gmail.com>
wrote:
Wow! Got a Mac Color Classic for $25! :oD And I made it work :oD
Now I have a computer for that //e card :o)
But it is slow, unbelieveable slow. Is there a way to speed it up
without
changing the main board? Can I overclock it? I already maxed the
memory (but have no VRAM SIMM module) and no FPU, but 16MHz is too slow :(
A 575 board would be great, but seems it has a premium price nowadays
A little of history:
Got this Color Classic and of course, no boot. Took off the
motherboard and
there was the classic signals of old computers from 90's:
Dead PRAM battery, lots of leaked capacitors, tons of dirt. Cleaned the
board, changed the capacitors, cleaned the goop with MEK, put a CR2032 with
a socket to work as a PRAM battery replacement (these aren't easy to find
here in Brazil) and it booted. No "bong", no sound. But it booted properly
and loaded system 7.*.*,
On shutdown, it BANGed something, and the classic smell of rotten
capacitors
was felt on the room. I disassembled the computer and wasn't
able to find anything. Now the computer wouldn't boot, but no HD. Without
the motherboard, the HD would spin up and thereafter, spin down.
After disassembling the entire computer, I found the hard disk (!)
with 4
leaked capacitors. I changed the capacitors and it still wouldn't
boot, turning down the HD after some seconds. I changed the HD to another
SCSI I had here from my HP16505A and it wouldn't spin down. HD problem.
A more detailed exam shown capacitor goop on the HD digital board. I
cleaned
it with MEK and it is working properly.
Unfortunately, I'm still unable to make it bong. No sound
whatsoever. I
tried to use an earphone on the audio output, but got no
sound. Changed all the polarized caps on the motherboard (even tantalum
ones) and no cigar. I still cannot figure what can be wrong. The audio
amplifier SEEMS to be working.
Interesting point: It bonged ONCE.
Tips, suggestions, hints, are welcome :o)
This is probably of no use at all, but an anecdote:
Not having your skills, when I got a dead Classic II, this is what I found.
I removed the logic board & discovered that it too had many leaking
caps. I removed all its socketed devices (SIMMs, ROMs) & put it
through my dishwasher (!). This removed the leaked electrolyte & when
thoroughly dried (2 days in a heated cupboard) I replaced it and the
machine booted and ran fine.
But, after this, the sound volume was very low.
Months later, it died again. The caps had leaked more. I dish-washed
it again and this time it only ran for a short time - hours - before
dying. There was no sound at all by now.
I can't solder worth a damn, so I can't fix it. :?(
--
Liam Proven ? Profile: http://lproven.livejournal.com/profile
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