My workhorse IIGS died today. Worked fine yesterday. Rom01, CFFA3000 (#1),ZipGS 8/64 (#2), VidHD (#3),
Uthetnet II (#4), Superdrive controller (#5, inactive), empty (#6), Hi-speed SCSI (#7, inactive). Lights on
CFFA, ZipGS, UthernetII active when powered on.
gives no beep.
I checked power supply which gives good +/-5v and +/- 12v readings.
In article <babda48c-2469-4d08...@googlegroups.com>,Thank ypu Craig. Replaced ZipGS with 65816 DIP. Not much change. Tested PS under load. Not good! Disassembled PS and found blown capacitor (1000uF?) in DC end. (Reactive Micro universal power supply kit less than a year old.) I will try replacing capacitor but my soldering skill sucks ;-). My other GS (rom3) died the same day. Its old PS gave up the ghost too. Not my day.
Steven Nelson <nelso...@gmail.com> wrote:
My workhorse IIGS died today. Worked fine yesterday. Rom01, CFFA3000 (#1),ZipGS 8/64 (#2), VidHD (#3),
Uthetnet II (#4), Superdrive controller (#5, inactive), empty (#6), Hi-speed SCSI (#7, inactive). Lights on
CFFA, ZipGS, UthernetII active when powered on.
gives no beep.
Can you remoe the ZipGS and try the stock configuration?
I checked power supply which gives good +/-5v and +/- 12v readings.Did you check this under load while it was connected to the motherboard?
On Monday, April 12, 2021 at 6:24:13 PM UTC-5, Craig Ruff wrote:
In article <babda48c-2469-4d08...@googlegroups.com>,
Steven Nelson <nelso...@gmail.com> wrote:
My workhorse IIGS died today. Worked fine yesterday. Rom01, CFFA3000
(#1),ZipGS 8/64 (#2), VidHD (#3),
Uthetnet II (#4), Superdrive controller (#5, inactive), empty (#6),
Hi-speed SCSI (#7, inactive). Lights on
CFFA, ZipGS, UthernetII active when powered on.
gives no beep.
Can you remoe the ZipGS and try the stock configuration?
Did you check this under load while it was connected to the motherboard?
I checked power supply which gives good +/-5v and +/- 12v readings.
Thank ypu Craig. Replaced ZipGS with 65816 DIP. Not much change.
Tested PS under load. Not good! Disassembled PS and found blown
capacitor (1000uF?) in DC end. (Reactive Micro universal power supply
kit less than a year old.) I will try replacing capacitor but my
soldering skill sucks ;-). My other GS (rom3) died the same day. Its
old PS gave up the ghost too. Not my day.
Take care. Apple2-4FR.
--Steven
It’s well worthwhile to practice soldering if you’re into retrocomputing. In a couple of hours you’ll be proficient enough. ;-)
Michael J. Mahon wrote:
It’s well worthwhile to practice soldering if you’re
into retrocomputing.
In a couple of hours you’ll be proficient enough. ;-)
Or you'll have burned your fingers. It's either one or the other. ;-)
Michael J. Mahon wrote:
It’s well worthwhile to practice soldering if you’re into retrocomputing.
In a couple of hours you’ll be proficient enough. ;-)
Or you'll have burned your fingers. It's either one or the other. ;-)
lasted a few minutes and then died. Examining the power supply it was
the new capacitor that was bulging - failed. No smoke, burning signs or
bad odor. But, to misuse a cliche, what is the 'magic smoke' telling
me? Should I replace the cap and try again? Thanks.
Update: The hard part in repairing power supply was desoldering the old bulging capacitor but with patience it finally popped out. Soldering new capacitor (1000uF, 16V like the old one) onto board was easier. No
burned fingers yet. The rebuilt power supply booted up the GS. It
lasted a few minutes and then died. Examining the power supply it was
the new capacitor that was bulging - failed. No smoke, burning signs or
bad odor. But, to misuse a cliche, what is the 'magic smoke' telling me?
Should I replace the cap and try again? Thanks.
--Steven
Steven Nelson <nelso...@gmail.com> wrote:Craig and Michael are right on, correct. I installed the capacitor in same polarity as the one on each side. Wrong. I looked at another identical power supply and it has the bad cap with the opposite polarity. The caps are like pairs each with opposite polarity. So desoldering and soldering in a new cap with correct polarity and all is working again. Whew. Thanks to all for helping me 1) tackling the solder sucker and soldering iron 2) fixing my polarity problem. Apple2-4FR
Update: The hard part in repairing power supply was desoldering the old bulging capacitor but with patience it finally popped out. Soldering new capacitor (1000uF, 16V like the old one) onto board was easier. No
burned fingers yet. The rebuilt power supply booted up the GS. It
lasted a few minutes and then died. Examining the power supply it was
the new capacitor that was bulging - failed. No smoke, burning signs or bad odor. But, to misuse a cliche, what is the 'magic smoke' telling me? Should I replace the cap and try again? Thanks.
--Steven
Hmmm. That sounds exactly like what would happen if the new capacitor was installed with the wrong polarity. ;-)
Check that the cathode of the electrolytic capacitor is connected to the more negative potential. That would be ground for a +5v filter capacitor.
The other more remote possibility is that the new capacitor was defective.
Electrolytic capacitors are the only type that have a serious aversion to reverse polarity. Their markings are unambiguous, with, typically, a wide stripe adjacent to their negative terminal.
--
-michael - NadaNet 3.1 and AppleCrate II: http://michaeljmahon.com
Electrolytic capacitors are the only type that have a serious aversion to reverse polarity. Their markings are unambiguous, with, typically, a wide stripe adjacent to their negative terminal.
On Sunday, April 18, 2021 at 12:26:52 PM UTC-5, Michael J. Mahon wrote:
Steven Nelson <nelso...@gmail.com> wrote:
Update: The hard part in repairing power supply was desoldering the old >>> bulging capacitor but with patience it finally popped out. Soldering new >>> capacitor (1000uF, 16V like the old one) onto board was easier. NoHmmm. That sounds exactly like what would happen if the new capacitor was >> installed with the wrong polarity. ;-)
burned fingers yet. The rebuilt power supply booted up the GS. It
lasted a few minutes and then died. Examining the power supply it was
the new capacitor that was bulging - failed. No smoke, burning signs or >>> bad odor. But, to misuse a cliche, what is the 'magic smoke' telling me? >>> Should I replace the cap and try again? Thanks.
--Steven
Check that the cathode of the electrolytic capacitor is connected to the
more negative potential. That would be ground for a +5v filter capacitor. >>
The other more remote possibility is that the new capacitor was defective. >>
Electrolytic capacitors are the only type that have a serious aversion to >> reverse polarity. Their markings are unambiguous, with, typically, a wide >> stripe adjacent to their negative terminal.
--
-michael - NadaNet 3.1 and AppleCrate II: http://michaeljmahon.com
Craig and Michael are right on, correct. I installed the capacitor in
same polarity as the one on each side. Wrong. I looked at another identical power supply and it has the bad cap with the opposite polarity.
The caps are like pairs each with opposite polarity. So desoldering and soldering in a new cap with correct polarity and all is working again.
Whew. Thanks to all for helping me 1) tackling the solder sucker and soldering iron 2) fixing my polarity problem. Apple2-4FR
--Steven
On 4/18/21 1:26 PM, Michael J. Mahon wrote:
Electrolytic capacitors are the only type that have a serious aversion to >> reverse polarity. Their markings are unambiguous, with, typically, a wide >> stripe adjacent to their negative terminal.
Unless you consider them a type of electrolytic, tantalum caps are similarly adverse to wrong polarity. And they are much more entertaining when they fail
:-).
Steven Hirsch <snhirsch@gmail.com> wrote:
On 4/18/21 1:26 PM, Michael J. Mahon wrote:
Electrolytic capacitors are the only type that have a serious aversion to >>> reverse polarity. Their markings are unambiguous, with, typically, a wide >>> stripe adjacent to their negative terminal.
Unless you consider them a type of electrolytic, tantalum caps are similarly >> adverse to wrong polarity. And they are much more entertaining when they fail
:-).
Yes, I do consider them a type of electrolytic. Fortunately, I’ve never experienced one complaining about reversed polarity. ;-)
So far my worst capacitor fail was an X2 polypropylene line filter. Two
weeks later, I could still barely stand to be close enough to replace it!
So far my worst capacitor fail was an X2 polypropylene line filter. Two weeks later, I could still barely stand to be close enough to replace it!--- Synchronet 3.18b-Win32 NewsLink 1.113
--
-michael - NadaNet 3.1 and AppleCrate II: http://michaeljmahon.com
Sysop: | Gate Keeper |
---|---|
Location: | Shelby, NC |
Users: | 764 |
Nodes: | 20 (0 / 20) |
Uptime: | 41:04:01 |
Calls: | 11,275 |
Calls today: | 1 |
Files: | 5,288 |
D/L today: |
82 files (10,175K bytes) |
Messages: | 521,283 |