Apollo Mk 3 030 Repair (caution lots of images)
Hello there my fellow Amibayer's
Today I am very lucky to share some work I have been upto.
Over on EAB A chap named Rocs9005, was in need of help, for the last year his APollo card had been intermittent and lots of memory faults.
So I decided that I would help, Rocs sent the card, and the rest is the story.
Problems problems and problems -
When I first tested the card it wouldn't boot, but when I changed the ram to a spare 16mb I have here, she was working perfectly (at 40mhz).... for about maybe 10 minutes... and then the guru's kicked in.
The chip was running on the uncomftably warm side (that means bloody hot) - usually there is a heatsink on the SMD components but this one has been removed - who ever removed it should be hunted down =)
I tried the chip running at 33mhz and she booted with 16mb ram, however it wasnt' 2 minutes before alerts kicked in and guru's
I tried again on 25 mhz and nothing, and now she wont boot with ram in at any frequency.
I tested the unit on a known good 1D4 with 512mb CF card.
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After I inspecteded the card, and I discovered that the second port was put in by a non-third party, probably an enthusast, allthough a little messy, it checks out fine under the optics and mr.continuity meter.
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So what do I do ?
Well theres no doubt that I need to remove the SMD based 030 and fit a socket for a PGA 030.
My plan is simple, after removed the chip and putting a PGA socket in place, I have a spare PGA unit rated for 40mhz that I bought this for my GB1000 mobo, but I wont get to the project for the next couple of months so Rocs9005 can have this for a replacement, no rush =D
Well chaps and chapesses - lets get to work eh?
Fluxin' it up =D
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HUzzah! hot air.... accept no substitute =D
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Ooo they wernt there before
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Remember - Cleaning is IMPORTANT =D
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WHOA!! whats going on there?
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______ Important Thred News break ________
unfortunately in removing the original CPU, two small tracks were damaged. this is mainly due to the age of the solder (brittle), pcb substrate (soft with heat) and my mistake of droping the cpu as I was picking it up off the board =(
Anyway, after a crazy moment - using some fetching commodore blue 30AWG wire - I re-routed the damaged two tracks.
We appologies for interupting the thread program.
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The Close up of closeup's
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.... so does it work?
Some Jig'd up WHDLoad love =D
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It wasn't all sunshine and roses thought
After replacing the CPU and attempting to run the card at 40mhz, it would NOT boot with ram in.
I tried stick after stick, from 50ns to 80ns, with WAIT-states and without, if there was memory installed it just would not boot.
I had a hunch and so reduced the clock to 33mhz and the card booted but ONLY with ram in the second port.
"The very strange thing is, out of 20 or so sticks I have at hand here, the card will only boot on 5 of these ram sticks, and ONLY with the WAIT enabled."
Perhaps even more peculiar is the fact that the 50ns stick (very fast refresh) wont work with the card!?
This leads me to conclude that the memory controller has been damaged in some way, either when the 2nd port was added, or just by age and CPU over-cooking and putting stress on the memory latching mechanisims.
Alas it is unfortunate as I cannot change the memory controller as its based in a CPLD, (Mach chip) - as such theres little choice but to work-around it.
However it is resurected from a dead running with a PGA MC68030RC40@33MHz + 32MB in 1 stick ram
settings -
RAM = ON
SCSI = OFF
WAIT = ON
stable running demo / whdload games / sysinfo cpu bench and memory 32bit fast benching
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Just under 5,000 Dhystones, not bad for a 33mhz 030
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ripping up the native IDE at 1.6MB a second on CF.... although it eats all the CPU time.
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Yet another speed test! give that CPU a work out
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I used a program calld MIPS, and ran through 100,000,000 iterations, final score 10.23 MIPS = NICE
Very pleased about the repair, it worked solid for 2 days here, after bench after whdload after bench, being powered on and off, the card removed and inserted.
she is now wigning her way back to Rocs9005, whom shares a passion for synths and tracking - good luck my friend +D
