DEC 3000/600 Alphaserver problems
PETER at beyondthepale.ie
Wed Jan 12 12:59:25 CST 2022
On Wed, 12 Jan 2022 at 11:02:47 -0600 Jon Elson wrote:
> On 1/11/22 5:17 PM, Peter Coghlan via cctalk wrote:
>> Thanks Jon.
>> Here is a badly focused picture of the suspect components:
> WOW, I don't know what those are! They look like big
> ceramic caps to me, but if they don't have any polarity
> marking, then they can't be Tantalum. Big multilayer
> ceramics are prone to cracking due to board flexing, and
> that can cause catastrophic failure, too.
Thanks again Jon.
They do have spikes of solder sticking out from the positive ends
which can be seen in the picture. There are no circuit references on
the I/O board where the picture was taken. However there are markings
on the system board including little + signs at the same ends as the
solder spikes on similar capacitors on that board.
I tried desoldering one from the middle of the picture using two
soldering irons - I'm not very good at this surface mounted stuff :-(
It came out ok though. I must have got lucky and picked a good one
because it measured 47uF in the capacitance section on my multimeter.
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