19 May
2014
19 May
'14
6:22 p.m.
Howdy all! I just found a PC/AT with monitor and keyboard, but even with
all but video card removed I get no POST / ram count.
Where do I start first on this type of machine?
I also got two PS/2 Model 70s in the same lot, but they both boot into
error 161 and 163 but can escape into BASIC just fine. Need to make the
config disk to sort them out ....
--
Gary G. Sparkes Jr.
KB3HAG
19 May
19 May
6:44 p.m.
On Mon, 19 May 2014, Gary Sparkes wrote:
Howdy all! I just found a PC/AT with monitor and
keyboard, but even with
all but video card removed I get no POST / ram count.
Where do I start first on this type of machine?
What kind of video card?
Remove the video card, and put in a CGA card and monitor. If that's not
available, an MDA card.
Is the power supply working? Start by checking for +5V and +12V on the
drive connectors. If there, than check the motherboard power connectors.
Do you have, or have access to, a P.O.S.T. card?
--
Grumpy Ol' Fred cisin at xenosoft.com
6:58 p.m.
On Mon, 19 May 2014, Gary Sparkes wrote:
Howdy all! I just found a PC/AT with monitor and
keyboard, but even with
all but video card removed I get no POST / ram count.
Re-Connect the power supply to the hard drive. Those power supplies need
a load to operate. The motherboard itself MAY be adequate, but if not,
power the hard drive, also.
7:22 p.m.
The PSU seems to operate fine. I get steady green on the power and can hear
the drive spin up.
On Mon, May 19, 2014 at 9:58 PM, Fred Cisin <cisin at xenosoft.com> wrote:
On Mon, 19 May 2014, Gary Sparkes wrote:
--
Gary G. Sparkes Jr.
KB3HAG
Howdy all! I just found a PC/AT with monitor and
keyboard, but even with
all but video card removed I get no POST / ram count.
Re-Connect the power supply to the hard drive. Those power supplies need
a load to operate. The motherboard itself MAY be adequate, but if not,
power the hard drive, also.
20 May
20 May
2:36 p.m.
The PSU seems to operate fine. I get steady green on the power and can hear
the drive spin up.
It's best not to assume anything (I've wasted hours looking for faults in
one area of a machine ahving assumed another part was correct becuase it
seemed to be, only to find that thet's where the problem really was)
Start with a voltmeter and check each supply votlage at the motehrboard
connector. Also check the power OK line , which I think, should be a TTL
high level when the machine is operational.
If all those are OK, then I would check for activity (toggling) on the
important signals -- the addres and data lines, ROM chip sleect, RaM
address, RAS/ and CAS/ and so on. Jsut to get some idea if anything is
working, This will pick up problems like no CPU clock, or the system
stuck i nthe reset state.,
-tony
7:06 p.m.
Looks like I'll have to head down south and grab some of my test gear. Been meaning to
do that anyway.
Sent from my iPhone
On May 20, 2014, at 17:36, ard at p850ug1.demon.co.uk (Tony Duell) wrote:
The PSU seems to operate fine. I get steady green on the power and can hear
the drive spin up.
It's best not to assume anything (I've wasted hours looking for faults in
one area of a machine ahving assumed another part was correct becuase it
seemed to be, only to find that thet's where the problem really was)
Start with a voltmeter and check each supply votlage at the motehrboard
connector. Also check the power OK line , which I think, should be a TTL
high level when the machine is operational.
If all those are OK, then I would check for activity (toggling) on the
important signals -- the addres and data lines, ROM chip sleect, RaM
address, RAS/ and CAS/ and so on. Jsut to get some idea if anything is
working, This will pick up problems like no CPU clock, or the system
stuck i nthe reset state.,
-tony
21 May
21 May
12:48 p.m.
Looks like I'll have to head down south and grab some of my test gear.
Been meaning to do that anyway.
YEs, I thgink you will :-). As I said in one of my HP repair articles,
you can't see logic levels or PSU votlages, you have to use test
equipment to detect them/
Without said test gear you are, effectively, blind. Which is not a Good Thing
Sent from my iPhone
Sent, appropriately enough, from a much-hacked IBM 5170.
-tony
20 May
20 May
8:27 a.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf
Of Gary Sparkes
Sent: Monday, May 19, 2014 8:22 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: PC/AT First Steps
Howdy all! I just found a PC/AT with monitor and keyboard, but even with all but video
card removed I get no POST / ram count.
Where do I start first on this type of machine?
I also got two PS/2 Model 70s in the same lot, but they both boot into error 161 and 163
but can escape into BASIC just fine. Need to make the config disk to sort them out ....
--
Gary G. Sparkes Jr.
KB3HAG
Error 161 is CMOS battery failure, and Error 163 is Time/Date not set. Replace the CMOS
battery, set the date and time, and things will start to straighten out. IIRC, it
requires a rectangular battery with 4 connectors on the lead? Mouser still sells these.
Cindy
21 May
21 May
1:48 a.m.
On Tue, 20 May 2014, Electronics Plus wrote:
Error 161 is CMOS battery failure, and Error 163 is
Time/Date not set.
Replace the CMOS battery, set the date and time, and things will start
to straighten out. IIRC, it requires a rectangular battery with 4
connectors on the lead? Mouser still sells these.
No, the 8570 uses a Dallas DS1287. I know that since I've piggy-backed a
lithium cell on that part for a 8570 with exact the same problems a few
weeks ago.
And what is a rectangular battery with 4 connectors? Older PS/2s need CRP2
batteries (known e.g. from photo equipment).
Christian
12:53 p.m.
And what is a rectangular battery with 4 connectors?
Older PS/2s need CRP2
batteries (known e.g. from photo equipment).
I think the OP was thinking of the 5170, whcih uses a 2-cell lithium
battery (in a cuboidal moulded plastci case, fixed ot the chassis with
velcro) with a cable ending in a 4-home 0.1" bitch socket. Obviosuly only
2 of the contacts are used, and I think one of the others is blanked off
as a polarising key.
The 5162 (XT/286) uses a cameara-type 2 cell lithium battery in a plastic
holder that fits in place of that blanking plate o nteh XT chassis.
On this machien I wired a 4 AA cell holder ot the connector. Every fw
eyars I ahve to fit 4 new Duracells, but they're cheap and easy to get
which is more than can be said for the origianl lithium battery.
-tony
20 May
20 May
11:22 a.m.
On 05/19/2014 08:22 PM, Gary Sparkes wrote:
Howdy all! I just found a PC/AT with monitor and
keyboard, but even with
all but video card removed I get no POST / ram count.
Any beeps with the video board removed?
Does the motherboard seem to be physically OK? Watch out for battery
corrosion on the PCB.
11:36 a.m.
The battery was velcro'd to the side, so no issues there.
Looks in very good condition, no beeps with video removed.
On Tue, May 20, 2014 at 2:22 PM, Jules Richardson <
jules.richardson99 at gmail.com> wrote:
On 05/19/2014 08:22 PM, Gary Sparkes wrote:
--
Gary G. Sparkes Jr.
KB3HAG
Howdy all! I just found a PC/AT with monitor and
keyboard, but even with
all but video card removed I get no POST / ram count.
Any beeps with the video board removed?
Does the motherboard seem to be physically OK? Watch out for battery
corrosion on the PCB.
12:11 p.m.
On 05/20/2014 11:22 AM, Jules Richardson wrote:
Does the motherboard seem to be physically OK? Watch
out for battery
corrosion on the PCB.
A really idiotic suggestion, but I had it happen to me. Make sure that
the BIOS PROMs are in the proper sockets and in the proper orientation.
A 286 motherboard that I received had not only the wrong EPROM in the
sockets, but they were reversed in each socket. Needless to say, they
were toast.
--Chuck
3873
days inactive
3874
days old
13 comments
7 participants
participants (7)
-
ard＠p850ug1.demon.co.uk -
cc＠informatik.uni-stuttgart.de -
cclist＠sydex.com -
cisin＠xenosoft.com -
jules.richardson99＠gmail.com -
mokuba＠gmail.com -
sales＠elecplus.com