A3000 - No video

Arc/RPCs, peripherals, RISCOS operating system & ARM kit eg GP2x, BeagleBoard
sh0dan
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A3000 - No video

Postby sh0dan » Wed May 17, 2017 7:50 am

Sorry in advance, I'm both new to vintage acorns and looking for help. Last time I owned one it was new, came in a nice box and generally involved less "do it yourself".

I like others have bought a couple of Acorns recently, models I previously owned or had as a child.

The first is an A3000 and I'm having issues already. I have read through other similar posts and will try and summarise what I've done so far underneath. However the outcome is - no video/display.

The A3000 came with an ARM 3 chip, RISC OS 3 roms, Econet expansion, hard drive podule and memory expansion. It also came with a leaky CMOS battery.

I've cut out the CMOS battery and cleaned up (could be better) the area with 50/50 distilled vinegar/deionised water then IPA. I didn't really get any fizzing but there is some corrosion to solder. The tracks appear ok visually, however its a possible problem area. There is currently no battery attached.

In order to do the above I stripped everything out/off the main board. To test I re-added the ARM 3 chip, keyboard, speakers, floppy and roms only. I'm concerned I might have damaged the roms as I did a terrible job of putting them back in. The board may be configured for things which are not currently there. Also, I noticed the keyboard cable is missing bits of black in the lines however all seem to have "some" black all the way down, i.e. no obvious breaks.

When testing with an RF cable I cant tune in to a picture. Although, I think I can see something in the static around 92mhz that disappears when I turn the A3000 off.

When testing with a monitor (Iiyama 431S-B, among others tried) and 15 pin to 9 pin adaptor I get a message saying "H:15.6KHz V:50.0Hz is out of range". This is with the T key depressed at power on, DEL shows nothing.

When testing I have tried various keys + power on. Including DEL, T, 1, 2, 3, 4, 5. Generally when testing I stick to DEL or T.

When testing I get the power light, plus caps lock and num lock toggle their respective key lights on and off. The num lock light is very dim. I cant get a similar light to show on scroll lock.

When testing a beep can be heard on power on.

When testing a beep can be heard after pressing CTRL-BREAK.

I cant get CTRL-G or COPY to make a beep with or without pressing F12 first.

I have tried blindly typing *conf stuff with and without pressing F12 first, no success. Same with *CAT, nothing.

I get nothing at all from the floppy, no flashing of lights. I do have a knackered A7000 which I could swop the floppy out of if it were compatible and someone thinks its worth trying.

LK24 is set to north, LK25 is closed.

Zarchos
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Re: A3000 - No video

Postby Zarchos » Wed May 17, 2017 7:54 am

There's hope !
It must be an issue with your monitor : use a TV.
Switch it to AV mode, RGB.

If you can't or only get a black screen you must have an active SCART lead (SCART with a battery or power supply).
I make these if you're interested.

Try to connect to a monitor (RGB) or SCART equiped TV.
A3000s don't output the exact right frequency for VGA screenmodes.
He's alive and well don't worry.
If it beeps and no flashing led diskette drive you can breathe.

A rare A3000 with an ARM3, you lucky b...d sorry : man !

sh0dan
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Re: A3000 - No video

Postby sh0dan » Wed May 17, 2017 8:02 am

Zarchos wrote:He's alive and well don't worry.

A rare A3000 with an ARM3, you lucky b...d sorry : man !


I'm very happy to hear that. I've spent hours reading forums in bed... its not looking good from my end.

I dont have anything but vga and rf cables. If its worth the investment, its not totalled, I'll look at buying one. As far as longer term, I'd like to use an LCD but at the moment anything that works.

Rare? I have no idea :( Maybe I should have given it to someone who knows what they are doing!

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danielj
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Re: A3000 - No video

Postby danielj » Wed May 17, 2017 8:05 am

Zarchos is right. The A3000 doesn't put out proper VGA frequencies, so doesn't "quite" work with many vga monitors. There is a fix for that, but in the meantime, you could try the composite out as a quick test before getting a scart cable made up! :)

d.

edit: VIDC enhancer to fix scan-rates: http://www.retro-kit.co.uk/Ultra-VIDC-Enhancer/

Zarchos
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Re: A3000 - No video

Postby Zarchos » Wed May 17, 2017 8:08 am

sh0dan wrote:
Zarchos wrote:He's alive and well don't worry.

A rare A3000 with an ARM3, you lucky b...d sorry : man !


I'm very happy to hear that. I've spent hours reading forums in bed... its not looking good from my end.

I dont have anything but vga and rf cables. If its worth the investment, its not totalled, I'll look at buying one. As far as longer term, I'd like to use an LCD but at the moment anything that works.

Rare? I have no idea :( Maybe I should have given it to someone who knows what they are doing!


I answered very quickly to your initial post to reassure you.
There can be something to do about the sync jumpers.
Others will tell.
If you want a battery powered SCART lead tell me, I can provide that at a *. member price.

Let the others, more knowledgeable than me, help you with the sync bits, 1st.

And yes you're lucky to have an ARM3 in your A3000, it is very rare because it needed removing the ARM2, installing a socket to plug in the ARM3.

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trixster
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Re: A3000 - No video

Postby trixster » Wed May 17, 2017 9:33 am

Do you know if your iiyama monitor supports 15khz modes? If it does then changing some jumpers and sync might get a display.

Have a look at my post in this thread to see what I did to get my display working

http://www.stardot.org.uk/forums/viewto ... 30#p169099
A3020 | A3000 | BBC B + 128K RAM/ROM + 20K Shadow + Pi0 + VideoNuLA
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sh0dan
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Re: A3000 - No video

Postby sh0dan » Wed May 17, 2017 11:18 am

I only have a few minutes at lunch to provide a quick reply but I will answer other questions tonight. Thanks all so much for your help.

I am a spanner! "Composite"... you mean in to the port I had been plugging an RF cable in to :) I'm so sorry. I read so much and still missed the obvious.

I have now plugged a composite cable to scart and... its alive! I have a desktop!!!

At first glance its black and white I think and other than ctrl-break the keyboard appears not be responding. For example, F12 does nothing.

Zarchos
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Re: A3000 - No video

Postby Zarchos » Wed May 17, 2017 11:36 am

Did battery leakage reach the keyboard connectors and / or the chips beneath (South) them ?

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DutchAcorn
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Re: A3000 - No video

Postby DutchAcorn » Wed May 17, 2017 11:38 am

sh0dan wrote:I only have a few minutes at lunch to provide a quick reply but I will answer other questions tonight. Thanks all so much for your help.

I am a spanner! "Composite"... you mean in to the port I had been plugging an RF cable in to :) I'm so sorry. I read so much and still missed the obvious.

I have now plugged a composite cable to scart and... its alive! I have a desktop!!!

At first glance its black and white I think and other than ctrl-break the keyboard appears not be responding. For example, F12 does nothing.

Composite is monochrome on the A3000, so that's fine. Do you have a mouse to launch !Edit and check what keys do and do not work?
Paul

sh0dan
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Re: A3000 - No video

Postby sh0dan » Wed May 17, 2017 12:07 pm

I'll send a picture tonight. There was a small amount of blue/green gunk around the keyboard socket but not much. Nothing on the under side of the main board. The tracks on the keyboard cable were my original concern... I wondered about chopping off the bottom so I have "fresh" plastic ribbon cable in the socket?

At the moment I dont have a mouse, but the A3010 coming later this week does have one I can borrow.

Is there any way of forcing it to boot to the supervisor prompt / command prompt to check keys?

Zarchos
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Re: A3000 - No video

Postby Zarchos » Wed May 17, 2017 12:27 pm

sh0dan wrote:I'll send a picture tonight. There was a small amount of blue/green gunk around the keyboard socket but not much. Nothing on the under side of the main board. The tracks on the keyboard cable were my original concern... I wondered about chopping off the bottom so I have "fresh" plastic ribbon cable in the socket?

At the moment I dont have a mouse, but the A3010 coming later this week does have one I can borrow.

Is there any way of forcing it to boot to the supervisor prompt / command prompt to check keys?


Yes : remove the battery (or cut one pin) ... and of course don't press DELETE when powering it on.

Don't chopp off the bottom until you've checked with your a3010 keyboard : it'll be eventually a solution (and yes it works).

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DutchAcorn
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Re: A3000 - No video

Postby DutchAcorn » Wed May 17, 2017 2:06 pm

Failing that you can use the attached floppy image. It is an 800K ADFS image of a bootable floppy that will take you to the command prompt.

Just reset the computer while holding shift (or use shift-ctrl-break).
Attachments
Boot2Command.zip
(365.48 KiB) Downloaded 8 times
Paul

sh0dan
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Re: A3000 - No video

Postby sh0dan » Wed May 17, 2017 7:33 pm

I've a little more time to reply properly. Thanks again for the kind help.

Zarchos wrote:I make these if you're interested.

I am, assuming I can get the keyboard working :) I cant currently send you a private message but would you mind sending me a price. I live in Norfolk, UK. PS thanks again for the quick response... it did give me hope.

trixster wrote:Do you know if your iiyama monitor supports 15khz modes?

I purchased the monitor for 20 quid (inc postage) specifically for this purpose based on some information in this page http://www.retro-kit.co.uk/page.cfm/con ... A-Adapter/ ... although always knew it was a long shot. The quoted "IIyama 17" ProLite E430S" seems to share the same specification as my "IIyama 17" ProLite E431S-B" but that specification indicates it does not support 15khz. Im also testing against a tv's vga input which I thought would but dosent show anything either. I've had a read through the linked posts, will try again when I get the keyboard sorted. I've seen the gbs8200 on ebay so that might be worth another look.

Zarchos wrote:Did battery leakage reach the keyboard connectors and / or the chips beneath (South) them?

Attached some photos of it before cleaning.

Zarchos wrote:Yes : remove the battery (or cut one pin) ... and of course don't press DELETE when powering it on.

I dont get a supervisor prompt, I get "Error: AddressException". I assume thats to do with not having plugged the memory board back in. Either way I get a prompt so will now test the keyboard.

DutchAcorn wrote:Failing that you can use the attached floppy image.

Thanks, I'll have to try and dig out an old PC... windows 10 dosent support floppy disks without additional drivers (I believe!) :(
Attachments
IMG_20170510_121946.jpg
IMG_20170510_121207.jpg

Zarchos
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Re: A3000 - No video

Postby Zarchos » Wed May 17, 2017 11:21 pm

sh0dan wrote:I've a little more time to reply properly. Thanks again for the kind help.

Zarchos wrote:I make these if you're interested.

I am, assuming I can get the keyboard working :) I cant currently send you a private message but would you mind sending me a price. I live in Norfolk, UK. PS thanks again for the quick response... it did give me hope.


10 euros + shipping and you'll pay upon reception.
I think I've got 2 already assembled, about 180 to 200 cm long.
1 where the battery holder is near the Archie 9 pin connector ; 1 where it's near the SCART connector.
No jack for the sound : I consider the Archie deserves to be connected to a hi-fi (btw I can throw in a Burr Brown OPA if you wish. Can't remember how much they cost me so let's say an extra 8 € it'll help pay my Dunhills, and you'll get the socket, OPA, wires and capacitors + female stereo jack).

sh0dan
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Re: A3000 - No video

Postby sh0dan » Thu May 18, 2017 6:46 pm

Zarchos wrote:10 euros + shipping and you'll pay upon reception.

That sounds very reasonable to me! I'm happy not having sound via scart.

On the keyboard front...

The following keys appear not to work:
- y,u,p,h,n,m
- 1,5,6,7,8,0
- -,=,£,[,;
- Shift (right and left),Shift-Lock,Back-Space
- Insert,Home
- Up,Down,Right
- F5-F12,Print

And on the number pad:
- /,*,8,9,5,6,2,3,0

They seem to be in clusters.

Shift and Star seem unreachable so that counts out a lot of things I'd like to try.

I've read a few different sources that suggest using conductive paint/wire glue so I've bought some similar to this: http://qubeserver.com/Qube/projects/repairmembrane.html .

I've attached some pictures underneath. You can see that the front cable has been affected by corrosion. The socket still has some green in it as well, so it might also be worth some kind of sand paper cleaning or something maybe?

The other A3010 hasn't turned up yet.
Attachments
IMG_20170518_193439.jpg
IMG_20170518_193351.jpg
IMG_20170516_090005.jpg

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DutchAcorn
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Re: A3000 - No video

Postby DutchAcorn » Thu May 18, 2017 9:08 pm

sh0dan wrote:On the keyboard front...

The following keys appear not to work:
- y,u,p,h,n,m
- 1,5,6,7,8,0
- -,=,£,[,;
- Shift (right and left),Shift-Lock,Back-Space
- Insert,Home
- Up,Down,Right
- F5-F12,Print

And on the number pad:
- /,*,8,9,5,6,2,3,0

They seem to be in clusters.


Tom posted a mapping between the keys on the keyboard and the pins on the keyboard connector in this post.
Paul

sh0dan
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Re: A3000 - No video

Postby sh0dan » Fri May 19, 2017 6:44 am

DutchAcorn wrote:Tom posted a mapping between the keys on the keyboard and the pins on the keyboard connector in this post.


That's brilliant, thanks. I'll go through it tonight.

sh0dan
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Re: A3000 - No video

Postby sh0dan » Sat May 20, 2017 6:19 pm

I cant believe I'm saying this, but all keys appear to work... having painted back in the lines on the keyboard connector with the wire glue as suggested here: http://qubeserver.com/Qube/projects/repairmembrane.html .

Also the SVGA LCD is working after the commands:
*Configure Monitortype 4
*Configure Sync 0
*Configure Mode 40
(no idea if these are all required).

I'm still waiting for the A3010 to turn up with its mouse so no idea on mouse. I actually have a stack of three button ps2/serial mice but at the moment nothing to write the serial mouse driver to floppy that I've seen here: http://www.retro-kit.co.uk/page.cfm/con ... rchimedes/

To test the floppy drive I did a "*format 0", which I guess worked ok, but the screen on the vga kept flickering on and off while formatting. Is this expected, worrying?

Thanks again for all your help... I really thought it was dead so am very grateful!

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Re: A3000 - No video

Postby Zarchos » Sat May 20, 2017 6:45 pm

MODE 40 is out of range on my A5000 connected to a recent BENQ monitor, I guess it uses a lot of memory so DMA video refresh is slowed by the disk access when formatting.
So : yes : it is normal.
Why not try *CONFIGURE MODE 27 instead (16 colour VGA) ?

sh0dan
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Re: A3000 - No video

Postby sh0dan » Sat May 20, 2017 6:53 pm

Zarchos wrote:MODE 40 is out of range on my A5000 connected to a recent BENQ monitor, I guess it uses a lot of memory so DMA video refresh is slowed by the disk access when formatting.
So : yes : it is normal.
Why not try *CONFIGURE MODE 27 instead (16 colour VGA) ?


You are good! Yes mode 27 both works and dosent cause the same refresh issues.

Thanks!

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Re: A3000 - No video

Postby sh0dan » Sun Jun 18, 2017 10:02 am

Zarchos wrote:10 euros + shipping and you'll pay upon reception.
I think I've got 2 already assembled, about 180 to 200 cm long.
1 where the battery holder is near the Archie 9 pin connector ; 1 where it's near the SCART connector.
No jack for the sound : I consider the Archie deserves to be connected to a hi-fi (btw I can throw in a Burr Brown OPA if you wish. Can't remember how much they cost me so let's say an extra 8 € it'll help pay my Dunhills, and you'll get the socket, OPA, wires and capacitors + female stereo jack).


Zarchos, I'm not sure how to give you my address as I still haven't be allowed private messaging on this board. I'd like to buy one of your scart cables If I can, and assuming shipping from France wont cost a fortune (I dont often send things abroad).

(The A3010 turned up after a long delay! It works, I was a little impatient and applied "extreme" pressure on the mouse connector as the socket on the A3000 is corroded, but it did eventually go in to the A3000's mouse socket and more amazingly worked. I probably wont take it out again as I'm not sure the mouse socket would take a second attempt. )

Thanks again

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Re: A3000 - No video

Postby Zarchos » Sun Jun 18, 2017 10:43 am

No worries.
xltardy Xavier Louis Tardy and I use gmail.

For your mouse socket did you neutralize the leaking with vinegar ?
Do it, then let it dry a whole day.
Then spray a special electronic contact spray.
Again let it dry (you can shake the whole machine to get rid of the excess of fluid) then see if the situation improved.
Do the same for the mouse pins.
If necessary with a small flat headed screwdriver try to rub the pins, not too hard otherwise you will bend them or break them.

Hope this helps.
Again your machine has great specs with an ARM3.
How much did you pay if you don't find the question too embarrassing ?

Xavier.

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Re: A3000 - No video

Postby Zarchos » Sun Jun 18, 2017 11:22 am

I will add that with an ARM3 fitted you should not see a black screen when accessing the diskette drive when in VGA mode.
This means you have RO 2 fitted : it doesn't know you have a CPU with cache, and you need a small app to turn it on.
Not the case with RO 3 where by default if you have an ARM3 it is turned on.

I guess this small app is somewhere on your hard drive.

sh0dan
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Re: A3000 - No video

Postby sh0dan » Sun Jun 18, 2017 6:49 pm

Zarchos wrote:I will add that with an ARM3 fitted you should not see a black screen when accessing the diskette drive when in VGA mode.
This means you have RO 2 fitted : it doesn't know you have a CPU with cache, and you need a small app to turn it on.
Not the case with RO 3 where by default if you have an ARM3 it is turned on.

I guess this small app is somewhere on your hard drive.


I've taken a guess at your gmail email address and tried sending a message.

I used a 50/50 solution of white vinegar and deionised water, scrubbed the area and in particular the mouse socket before washing off with alcohol. The mouse socket and one of the resistors had a green crust on them. I got it off the resistor but not the mouse socket due the metal being concealed. I think I needed, as suggested, to leave the vinegar for longer and use a stronger solution but at the time I was worried about doing it and went for a softly softly approach.

Risc OS is version 3 and the configuration settings indicate a cache is on (pictures attached pre cleanup). Unfortunately the IDE drive tries spinning up a few times before failing. Thanks to preservation web sites I found the manual and software for the HCCS IDE interface and so was able to install a CF card instead. But, it means I dont have any of the original software. Its a CJE ARM 3 upgrade and I cant find a lot online at the moment, I'll keep looking.

No sure, I paid £51 for the computer and £12.99 for postage on it. I had bid on countless other ones before that and been outbid in the last x seconds every time! So I was overjoyed when I won that one! I should also say, I have another acorn which has severe battery damage and will probably only ever be useful as a door stop... so I was maybe due more luck.
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cache.jpg
RISCOS.jpg
ARM3.jpg

Zarchos
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Re: A3000 - No video

Postby Zarchos » Sun Jun 18, 2017 7:51 pm

Excellent price, really !
You don't need any software for the ARM3 when running RO 3 : if you want to slow down your machine just press F12 and CACHE OFF then ENTER
CACHE ON will set the cache on again
Any DP software will do that with the mouse, it installs on the icon bar and most of the time you get something graphical like a hare or a tortoise.

For the screen going blank in vga modes it must be because the memory bus is still at 8 Mhz, and not 12 Mhz ...
I don't remember an A5000 having this issue... or I am dreaming.
Last edited by Zarchos on Sun Jun 18, 2017 7:58 pm, edited 1 time in total.

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IanS
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Re: A3000 - No video

Postby IanS » Sun Jun 18, 2017 7:58 pm

Zarchos wrote:And your ARM3 upgrade can have a floating point unit, too !

No, that's just the socket where it fits into the motherboard.

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Re: A3000 - No video

Postby Zarchos » Sun Jun 18, 2017 7:59 pm

IanS wrote:
Zarchos wrote:And your ARM3 upgrade can have a floating point unit, too !

No, that's just the socket where it fits into the motherboard.


Yes I had corrected while you were sending your message.

steve3000
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Re: A3000 - No video

Postby steve3000 » Mon Jun 19, 2017 1:14 am

Nice ARM3! :D

Zarchos wrote:For the screen going blank in vga modes it must be because the memory bus is still at 8 Mhz, and not 12 Mhz ...

That's the reason. Arm3 doesn't fix this unfortunately, but the blanking should only happen for floppy discs, not hard discs, and only in high resolution (640x350 and above) 256 colour screen modes on 8mhz machines - that's only MODE 21, 28 and 40. All other modes should be fine.

sh0dan
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Re: A3000 - No video

Postby sh0dan » Tue Jun 27, 2017 8:44 pm

steve3000 wrote:Nice ARM3! :D
That's the reason. Arm3 doesn't fix this unfortunately, but the blanking should only happen for floppy discs, not hard discs, and only in high resolution (640x350 and above) 256 colour screen modes on 8mhz machines - that's only MODE 21, 28 and 40. All other modes should be fine.


Thanks. I think I can confirm that is whats happening.


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