Clym5 wrote:The odd thing is, I can't find ANY other cap with a 2 ohm reading. It's the uppermost red one, next to the P8 connector. You'll be able to see it in the photos.
Would a smoke test work? Or is that too risky? Tantalum caps can do some damage..
Check the resistance of the voltage lines again - I'm taking a guess that the pin "blue" would go to also reads 2 ohms to ground. If that's the case, I'd remove that cap.
Personally I prefer to remove than blow - but I haven't seen the kind of damage you describe from the MFM card before.
Here's a photo of how bad the yellowing is on the Wang: http://imgur.com/a/iTWfr
There's also that mystery "com card" that came with the computer. Any clue what it is?
Originally I thought it was just a serial card - but then I noticed it has a Z80 CPU. So one of those connectors is likely a high speed serial port (16450 UART) but the other I have no idea.
Sadly, my only spare unit is a 486. I've got two. A bare motherboard, with RAM and CPU, and a Digital Venturis 466.
I've got that model too - quite a tidy system. I have the matching monitor too "unused in box" from an ex-Digital employee - but it appears it got left in the box because the screen mask was damaged (damn it)
Also, do you know of a good way to replace a MFM hard drive without actually using a MFM drive? And if not, where might one be able to get a WORKING one? The last few that I've had have all been dead. Seized, and even if they went, wouldn't read anything. Sometimes, the heads came clean off and stuck to the platters!
Seizures are an issue when left too long - often the heads seem to become-one with the surface. I've had a few drives arrive seized - if it's the heads and they don't know off easily - you know you're in for a bad time. However "not reading" is quite normal. The logic is on the controller itself - so if you change controller brand/type you usually need to also perform a fresh low level format (writes the sector markers etc) - and even if the controller matches - there is a chance those markers have lost magnetic strength over the last 20+ years and need to be rewritten - which requires a fresh low level format
Generally if they spin up and self check OK there is an 80-90% chance a simple LLF will spring them back in to life. I do have quite a few of these, but prying them from me is quite difficult. I just got in an ST277R + controller landed from Ebay US for around $50 though - so if you hunt about you can get a good deal.
Unlike XT's, the AT style computer (286+) has hard drive support in the BIOS and a 16 bit data bus.
So if Winchester isn't of interest - you can just use a normal IDE controller and a matching IDE drive. If the drive doesn't match the built in drive types there are a few options to get around it.
I can definitely help with parts for that just because I have so many - 40Mb to 40Gb. If you wanted to swap that ST225 (assuming it spins up) I could sort you out a big package of tested-goodies depending on what you need/want (sound cards, hard drives, cards, cables etc etc).
I might have to take you up on the offer of parts, apparently this 3200SX wont boot! It's coming up from Christchurch now.
It's probably something really simple like a loose HDD connector, or the wrong drive type was set in the BIOS or someone formatted the HDD. It'll need a new CMOS battery too if it's the one I remember off trademe. I just used a couple of AA batteries in a holder and soldered it to the original wires.
If the drive is dead, I do have a stock pile of Conner IDE drives (which I purposely collect for Toshiba portables). I can't help with a floppy drive though if that's bung.