Subject: Re: more Multia repair part numbers and comments
To: Ross Harvey <firstname.lastname@example.org>
From: John Hayward <John.C.Hayward@wheaton.edu>
Date: 01/05/2001 17:58:45
Dear Alpha People,
Some time ago (ie 2-3 years) I had a Multia which was up running NetBSD.
Since then I needed the monitor for another machine and stopped using it.
I'm now in a situation where I can use this alpha (primarily as a router
running NAT for my DSL connection).
When I turned it on the monitor would not sync (it was a different monitor
than had run most reciently). I then connected a monitor had been
I recall seeing a message something like "waiting to boot".
After cycling power and trying several more times the monitor shows only a
block cursor. All three lights on the keyboard are on.
As I recall when it booted it went thru a cycle testing the video board
then presented some kind of boot menu.
Any suggestions on how to bring life back to this Multia?
On Tue, 28 Apr 1998, Ross Harvey wrote:
> Date: Tue, 28 Apr 1998 02:35:15 -0700 (PDT)
> From: Ross Harvey <email@example.com>
> To: port-alpha@NetBSD.ORG
> Subject: more Multia repair part numbers and comments
> OK, so I borrowed a supposedly dead Multia. Murphy's law is in fine form,
> though...when you _want_ a dead one, _specify_ a dead one, really can only
> _use_ a dead one (for the purpose of doing a friend a favor and testing the
> big multia fix) ...then...of course...it arrives and works just fine.
> Now that I've seen the parts, the bad news is that they aren't likely
> to be in any catalog...good thing for me no one took up my offer on that
> bet. AFAICT it is going to be necessary to order them through one of the
> manufacturer's franchised distributors, and they can be difficult when you
> don't already have an account. Sometimes you can order samples through
> a web page, and certainly you can locate the distributer that way.
> The generic thing you want is: (qty 6) a 20-lead .220 (i.e., medium
> body) soic 4.7K bussed (pullup) resistor network, with lead 20 as the
> common. I think the Bournes parts are probably safe, I guess it was a
> bad batch, or possibly that thick-film part didn't like actually being
> _in_ the solderwave, which is what would have happened given that these
> components are on the bottom of the board.
> And, I can now see why the Jupiter guys replaced the logic IC: on Tim's
> Multia the printing on the chip is starting to bake into a brownish
> off-white right in the center, i.e., over the die. I think it needs to
> go too, although using thermally conductive epoxy you could conceivably
> heatsink it...not much room to work with though. The 5% is perfectly
> fine as a tolerance, but if it is out of stock and the 2% or 1% is in
> WhichOne Mfr Part Number
> R-network Bournes 4820P-002-472
> R-network Dale SOMC2001472J (5%)
> R-network Dale SOMC2001472G (2%)
> R-network Dale SOMC2001472F (1%)
> ...there are probably more...
> Logic-IC TI SN74ABT623DW
> Logic-IC Philips 74ABT623D
> Logic-IC Pericom PI74FCT623TS
> Logic-IC Pericom PI74FCT623ATS
> Logic-IC Pericom PI74FCT623CTS
> Logic-IC Pericom PI74FCT623DTS
> Logic-IC IDT IDT74FCT623TSO
> Logic-IC IDT IDT74FCT623ATSO
> Logic-IC IDT IDT74FCT623CTSO
> ...there probably are not any more...
> This is almost trivial with the right lab, but it definitely isn't the
> easiest home project. Besides the difficulty of obtaining the components,
> you have 140 leads to remove and resolder...and you don't want to lift
> or destroy a single pad while doing it. At least it is a lot easier
> than if they were those ugly old dips.
> Ross Harvey