Power to a load tester is not the same as power in a system.
It is likely that one of the other voltages, other than 5V is
being loaded down with a shorted tantalum capacitor in
the system.
I doubt there is a problem with the supply.
Dwight
________________________________________
From: cctalk <cctalk-boun...@classiccmp.org> on behalf of Richard Cini
<rich.c...@verizon.net>
Sent: Sunday, May 29, 2016 4:16:15 AM
To: CCTalk
Subject: Re: PC/AT "power good" problems
Chuck –
My wording was probably less than precise, but “never comes out of
reset” means that it never POSTs. Nothing on the screen. No cursor. No boot
message. No BASIC. Keyboard does reset though (I see the three LEDs blink on,
then off). I watched for a good 5 minutes before giving up. It’s been a long
time since I worked with this machine but I’m pretty sure there is a sign-on
banner or something.
For comparison, I pulled my old original PC (64k/256k mobo) with
expansion unit and 10mb HD and it took an excruciatingly long time to boot, but
it did have a blinking underline cursor on the screen while it thought about
booting.
Rich
--
Rich Cini
http://www.classiccmp.org/cini
http://www.classiccmp.org/altair32
On 5/28/16, 10:30 PM, "cctalk on behalf of Chuck Guzis"
<cctalk-boun...@classiccmp.org on behalf of ccl...@sydex.com> wrote:
>On 05/28/2016 07:17 PM, Chuck Guzis wrote:
>
>> Bear in mind that the PC AT BIOS during POST goes through some
>> rather arcane protected-mode memory tests, using the CMOS "why did I
>> get here" byte when coming out of reset.
>
>...which reminds me--check the status of the "programmed reset" line
>coming from the keyboard controller.
>
>--Chuck
>
