Challenge S blew a tantalum cap - Printable Version
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Challenge S blew a tantalum cap - jan-jaap - 02-22-2019
I was building a mini-DIN8 to RJ45 serial adapter cable to connect systems using those (Indy, Indigo2 ...) to my Cyclades console server yesterday. Used my Challenge S to try out the finished product and after a couple of seconds realized the smell wasn't good. First I thought I screwed up my cable, but it blew a tantalum cap between the GIO sockets on the mainboard:
Took it to work this morning (I took this photo in the lab). Amazingly we still had some of those (10ยต 25V) in a box of old junk so if I have some time this afternoon I'll replace it.
The system never stopped working by the way.
RE: Challenge S blew a tantalum cap - dexter1 - 02-23-2019
Wow, looks like the Challenge S is not immune to blown Tantalum caps. I've seen this happen on Indy's at a different location near the Indycam connector, which renders the Indy unable to boot.
I looked around if these capacitors are common: Mouser has them:
https://eu.mouser.com/Passive-Components/Capacitors/Tantalum-Capacitors/Tantalum-Capacitors-Solid-SMD/_/N-75hr4?P=1z0wrkrZ1yx4awy&Keyword=10UF%2c25V&FS=True
RE: Challenge S blew a tantalum cap - Irinikus - 02-23-2019
I had to replace a blown Tantalum cap on the motherboard of my AlphaStation 255. The cap was associated with the PS/2 keyboard port. The result was that the machine wouldn't display graphically on boot. (It seems like it's a rather common fault with these machines)
It looks like there was a change to later motherboards, as the cap was orientated in the opposite direction in later revisions, with silkscreening to match, so when I replaced the cap, I orientated it in the way it was orientated on later motherboards. (now it works perfectly)
Because of this fault, I was able to buy two "defective" Alphastation 255's and constitute a very good AlphaStation 255 300MHz machine for $400!
RE: Challenge S blew a tantalum cap - jan-jaap - 02-24-2019
(02-23-2019, 12:19 PM)dexter1 Wrote: Wow, looks like the Challenge S is not immune to blown Tantalum caps. I've seen this happen on Indy's at a different location near the Indycam connector, which renders the Indy unable to boot.
I looked around if these capacitors are common: Mouser has them:
https://eu.mouser.com/Passive-Components/Capacitors/Tantalum-Capacitors/Tantalum-Capacitors-Solid-SMD/_/N-75hr4?P=1z0wrkrZ1yx4awy&Keyword=10UF%2c25V&FS=True
I can order from Farnell using a company account which saves a lot. But we still had a few.
The Challenge is back in working order. It's not my best soldering job ever, but we have only one soldering station for leaded work left and it didn't have a very fine tip in it.
This is what I was making, btw: a short pigtail cable from (female) RJ45 to mini-DIN8, with NULL modem crossover. Here it's tested with my Macbook, but normally it's to be used with my Cyclades ACS48 console server