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The Icon Bar: General: A3000 Blue Screen
 
  A3000 Blue Screen
  LDA (21:55 4/9/2014)
  qUE (23:33 4/9/2014)
    LDA (06:47 5/9/2014)
      geraldholdsworth (08:38 5/9/2014)
        LDA (13:29 5/9/2014)
          Phlamethrower (13:46 5/9/2014)
            LDA (21:10 5/9/2014)
  Acornut (11:00 7/9/2014)
    LDA (13:16 8/9/2014)
      Acornut (00:37 10/9/2014)
        LDA (12:37 6/10/2014)
          qUE (13:49 6/10/2014)
            LDA (20:20 7/10/2014)
              LDA (18:52 10/10/2014)
                LDA (19:59 10/10/2014)
                qUE (23:45 10/10/2014)
                  LDA (07:54 11/10/2014)
                    qUE (10:00 11/10/2014)
                      LDA (12:41 13/10/2014)
 
Lynn Davis Message #123327, posted by LDA at 21:55, 4/9/2014
Member
Posts: 11
Hi,
New here, I have taken out one A3000 from the coma.
There were no sign of life. no video output (blank signal).
After lot of work (tracks repair and component replacement,followed the advices of the A3000 SM), I have a sign of life: I have the Red screen, then Blue screen and it is stuck at the blue screen.

I tried to hold F12, R, T at start but nothing.

The floppy doesn't talk, the keyboard LED is not flashing.

Any idea ?

Thanks.
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qUE Message #123328, posted by qUE at 23:33, 4/9/2014, in reply to message #123327
qUE

Posts: 184
I assume you mean the border is red/blue, my memory of what the colours mean is a bit hazey. But it's likely either the RAM or CMOS checks have failed. The CMOS one can be really bad I'm afraid. I recommend opening up the case (with power off), first look underneath the keyboard to the left, if it looks green on the component legs in that area the battery has leaked which is potentially a nightmare, if so, I'd remove the battery and spray with a water repellent (WD40) to prevent any worse corrosion. At this point hopefully it hasn't eaten too far into the circuitry and you'll have a working mouse and keyboard (their circuitry is there). However if all is clear (or you've removed the battery you can try this), remove the memory sim located next to the floppy drive, close up the case and power on holding delete key. Hopefully it should boot up and you can type etc., if it's just the sim as an issue, the pins on the motherboard for the memory expansion need going over with contact cleaner and the sim put back. Let us know how you get on.
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Lynn Davis Message #123329, posted by LDA at 06:47, 5/9/2014, in reply to message #123328
Member
Posts: 11
Hello,
The board is already out and cleaned since a long time big smile
I have done all the SM checks with the scope.

Now I have the normal sequence when I power it up... the full screen is red, then blue and it stop here.
normally it should go to black and display the memory, and then boot Risc OS.

I guess you can't see those early colors if the computer is connected to a LCD screen...
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Gerald Holdsworth Message #123330, posted by geraldholdsworth at 08:38, 5/9/2014, in reply to message #123329
Member
Posts: 12
Is the floppy disc drive light flashing, just above the keyboard?
You could also have a look at:
http://www.waitingforfriday.com/index.php/Restoring_an_Acorn_A3000_computer
and
http://www.retro-kit.co.uk/page.cfm/content/Acorn-BBC-A3000-Battery-Maintenance/
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Lynn Davis Message #123331, posted by LDA at 13:29, 5/9/2014, in reply to message #123330
Member
Posts: 11
Hello,

In my initial message, I wrote :

"The floppy doesn't talk, the keyboard LED is not flashing."

No those links doesn't help as I'm not restoring, but repairing.

BTW, it can't be the CMOS (IC6) as the A3000 bring you to the supervisor prompt if the CMOS IC is missing.

For information, I have read A3000 Service Manual.

[Edited by LDA at 13:32, 5/9/2014]
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Jeffrey Lee Message #123332, posted by Phlamethrower at 13:46, 5/9/2014, in reply to message #123331
PhlamethrowerHot Hot Hot Hot Hot Hot Hot Hot Hot Hot Hot Hot Hot stuff

Posts: 15097
Apparently a blue screen corresponds to when it's running the following tests:

* RAM
* Video
* Sound

If a failure is detected it *should* change the screen colour to red and then flash out the error code using the floppy LED. But that isn't happening, so there's no easy way of telling which of the above three tests are failing.

http://www.retro-kit.co.uk/user/custom/Acorn/32bit/documentation/RISCOS-POST-AppNote225.pdf
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Lynn Davis Message #123333, posted by LDA at 21:10, 5/9/2014, in reply to message #123332
Member
Posts: 11
I quote: "If the simple memory test referred to earlier is passed, a more extensive test occurs. During this phase the screen color is changed to blue.
After the main memory test, tests are performed on the video and sound controller, VIDC. These are again
very brief."

I would say that the basic RAM test has passed as I'm stuck into the blue screen. I'm going to check back VIDC again...

I have already changed some semiconductors around VIDC because (before the blue screen) I didn't had the horizontal sync (no signal at all). If I compare, blue screen is way better big smile
It means that VIDC RGB output is working and I have the vertical and horizontal sync. yeah !
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Blind Moose Message #123334, posted by Acornut at 11:00, 7/9/2014, in reply to message #123327
Acornut No-eye-deer (No Idea)

Posts: 487
Has the chipset been upgraded to a Risc O.S. 3.11 or better? If I remember they originally shipped with 2.0 or something, which preceeded the useful self test colours/flashing floppy,etc. Not sure, but think the original 4 piece O.S. chipset, didn't completely fill the slots. ( 14 of the 16)

[Edited by Acornut at 17:27, 7/9/2014]
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Lynn Davis Message #123335, posted by LDA at 13:16, 8/9/2014, in reply to message #123334
Member
Posts: 11
Yes, I put Risc OS 3 but it doesn't flash...
(I already have seen the flashing code error report, I know what you are talking about, but unfortunately, it doesn't flash) big smile
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Blind Moose Message #123338, posted by Acornut at 00:37, 10/9/2014, in reply to message #123335
Acornut No-eye-deer (No Idea)

Posts: 487
I don't think holding F12 @ startup does anything. As far as i know it just drops you out of Desktop and into Basic. If you've not seen these.

Here's all the power-on options for RO3.7 and earlier: ( Thanks to Jason)

R : reset all OS CMOS
T : as R but configure the opposite video sync
Delete : reset all CMOS
Copy : as Delete but configure the opposite video Sync
Shift : reverse the operation of automated boot
Keypad 0-9 : change configured monitor type to specified number
Keypad . : change mode, sync and monitor type to Auto
Keypad * : force start up to a command line (called the Supervisor)
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Lynn Davis Message #123385, posted by LDA at 12:37, 6/10/2014, in reply to message #123338
Member
Posts: 11
After all these days, I'm happy to tell that I have fixed my faulty A3000. Another A3000 back in life.
Thanks to all.
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qUE Message #123386, posted by qUE at 13:49, 6/10/2014, in reply to message #123385
qUE

Posts: 184
What fixed it? (out of curiosity and for future reference for other users)

[Edited by qUE at 13:50, 6/10/2014]
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Lynn Davis Message #123387, posted by LDA at 20:20, 7/10/2014, in reply to message #123386
Member
Posts: 11
In fact it's not totally fixed smile
Remember that I come from a no output A3000, lot of work has been done. but it is in the right way smile

I have passed the blue screen and got the black Supervisor Screen but unsync'ed and scrolling...
To reach this point I have changed IC29 IC30 & IC31 : one or more is faulty, because when I put them one by one on another working board, so when I mix them with the working ones, RISC OS boot and RISC OS become unstable... (I have no time ATM which one is faulty because I'm trying to fix the A3000).

So, for now I put IC29 IC30 and IC31 from a working board.

Ok, back to the RISC OS scrolling screen... I tried R or Del but they don't work.

So the tip is to remove the CMOS, then I have the Blinking Diag which is working now. it indicate 9... It doesn't means anything buy I think it is trying to tell that the CMOS is missing smile after the blinking diag I got a stable RISC OS 1024K Supervisor screen smile

Cool now I can type... but not all the keys aren't working. R & Del doesn't seems to work... This is why is it almost fixed, because if I have R & Del working I can put back the CMOS and I'm sure it's going to work.

Now, why the keyboard isn't working properly : because I have reworked lot of tracks aroung SK6 & SK7 (were oxydized) ...

SK6 & SK7 has been removed to get this job done and I have also repaired a pin on one of the two 20WAYFLEX connectors. (I have adapted a pin coming from an IC Socket).

I would like to replace SK6 & SK7 (20WAYFLEX) but I didn't found those connectors anywhere ATM.

Now, the next step is to trace all tracks from SK6 and SK7.

Looking for those 20WAYFLEX connectors, so if you have a broken board don't hesitate to contact me smile



VIDC with some capacitors replaced (if I remind C108, C95,C100)



The battery replacement with a diode under the socket. The electrolytic capacitor has been replaced, the IC are mounted on socket. and some broken tracks fixed.



from the top to bottom, the only keys that I could get... R, DEL were not working...



IC29 IC30 IC31 replaced and socketed. The 220uF capacitor has also been replaced by a 330uF.


[Edited by LDA at 08:10, 11/10/2014]
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Lynn Davis Message #123391, posted by LDA at 18:52, 10/10/2014, in reply to message #123387
Member
Posts: 11
Ok I have fixed the keyboard, all keys are working now.



I can reset the cmos now, and randomly :

-Sometime I get an error on the back screen
-Sometime I have an error while booting RISCOS
-Sometime it boot RiscOS

Well it is unstable at the moment but it's a the right way.
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Lynn Davis Message #123392, posted by LDA at 19:59, 10/10/2014, in reply to message #123391
Member
Posts: 11
Someone got the TEST ROMS dumped ?
Thanks
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qUE Message #123393, posted by qUE at 23:45, 10/10/2014, in reply to message #123391
qUE

Posts: 184
thanks for replying, yeah I see your board has attack from a leaky battery from the keyboard connector in one of those shots. I have a few machines with this, I've not gone into trying to fix it, but I know once corrosion starts it causes all manner of mayhem, I expect you're going to be chasing IC routes if anything. I'm not sure even test ROMs will tell you the exact lines that are down, I reckon keeping with the line following and component testing might get you to the problem, but as you've already found, it's going to take time :(
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Lynn Davis Message #123394, posted by LDA at 07:54, 11/10/2014, in reply to message #123393
Member
Posts: 11
SK6 & SK7 are ok. I have all the keys working now. I don't need those connectors anymore smile one PIN was broken but I have fixed it with a pin coming from an IC Socket that I have moded.(you can see it in the pic, it's the second one of the second connector).

as you can notice in the pictures, I have sanded my motherboard around SK6, SK7, the 4 ROMS (the sockets have been replaced also) it is easier to see the damages...

Since yesterday the A3000 is working 100% stable, it bring me to RiskOS each time I power it on without errors. Resurected !

Next, I think I'm going to replace the rest of the capacitors I haven't replaced yet as they were reporting low ESR values.
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qUE Message #123395, posted by qUE at 10:00, 11/10/2014, in reply to message #123394
qUE

Posts: 184
That's good news. I only wish Acorn had originally put the CMOS battery as a seperate pack like on the Beeb.
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Lynn Davis Message #123397, posted by LDA at 12:41, 13/10/2014, in reply to message #123395
Member
Posts: 11
Here we go smile

https://www.youtube.com/watch?v=X3pv5ZJ3KNg
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The Icon Bar: General: A3000 Blue Screen