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It seems that I cannot have an Archimedes.

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flaviosr

Experienced Member
Joined
Aug 27, 2016
Messages
266
Location
Turin, Italy
Hello,
I have been looking for an Archimedes at a decent price for years and then I found it.
The issue is that I cannot get a clear image (and probably other issues) as it can be seen in the attached picture, using the mono connector that I suppose is a composite one, right?
I have also bought a DIN9 cable to SCART but I even cannot have the picture from the mono connector.
Any ideas? I completely do not know this computer... 😔
 

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Which Archimedes (e.g. A3000?) have you bought and can you provide a photograph of which connectors you have used please.

The archimedes (or at least the variety I know of) has internal links to select (for example) the polarity of the sync. signals for use with a variety of monitors. It is just possible that the links (if fitted) are not configured correctly for your monitor.

The Horizontal Sync. looks 'wrong' in your photograph.

 Dave
 
daver2 said:
Which Archimedes (e.g. A3000?) have you bought and can you provide a photograph of which connectors you have used please.

The archimedes (or at least the variety I know of) has internal links to select (for example) the polarity of the sync. signals for use with a variety of monitors. It is just possible that the links (if fitted) are not configured correctly for your monitor.

The Horizontal Sync. looks 'wrong' in your photograph.

 Dave
Click to expand...
It's an A3000. Is this one of the Archimedes to configure? Please find attached the photo of the cable I bought.
 

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Excellent.

That is a 9 pin D connector not a DIN connector. That is the bit that was confusing me yesterday...

Yes, the A3000 has the links.


See page 22 SK14 and links 24, 25, 26 and 27.

You will have to find another manual to identify where these links are and how to set them.

Dave
 
Last edited:
I have also found the attached PDF. So I have to work on five links (I suppose the first two are the most important). Now I look for their position.
I am not at home in these days but I will try next weekend.
Thank you
 

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In the meantime I have found 24 and 25...
 

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Have you looked under your keyboard? Left hand side back of the board under your keyboard there is usually a battery for the rtc that are notorious for exploding and destroying these boards. I hope yours has been removed already I spent several months last year restoring an A3000. Required lots of traces to be repaired
 
Excellent. You have found the description of the links.

Obviously, make a note of the link settings FIRST.

Check the specifications for the monitor you are using and try to find a compatible link setting.

Dave
 
Not sure if that was the case with the A3000 already, but you can press various keys at power-on to change video modes. The system is meant to work with a multisync display by default, but can also be set to VGA only, SVGA, or 15 kHz. Doing a full reset of the parameter ram is therefore the first thing to do.
 
My A3000 is the UK one so that it has "only" link 24 and 25. I have simply tried all 4 possible combinations and I had no results (I have not tried without any jumper in link 25, since it is not supposed to do). Please note that in my first picture of the video I have canceled a sentence in my language that says "no link"! My LG TV shows raw data and so "that" picture but, for example, my Triniton and other monitors show a black screen with composite output.
I have also tried a tool that can transform a lot of video type in VGA (it5 uses a Raspberry Pi 0) and I found a video output from DB9 connector but very distorted in all tool drivers (none for the Acorn) => this tool tells me that by default the video is a 30.75.
Having opened the computer I checked the battery and it was removed before making too much damage (see picture)... do you think there is something to repair?
I have also noticed that some chips are missing but I have found pictures with the same mixing chips.
Any ideas?
 

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I would clean that rubbish off and inspect the PCB tracks with bright sunlight and a magnifying glass looking for damage. I can't see from that photograph.

If you read page 28 of the service manual, IC1 and IC7 (the two empty IC sockets) are for the ECONET and serial port upgrades.

Dave
 
With a RISC OS machine, have you tried holding down delete when powering it up ?

It will reset the video to mode 0 15kHz.
 
flaviosr said:
Having opened the computer I checked the battery and it was removed before making too much damage (see picture)... do you think there is something to repair?
Any ideas?
Click to expand...
All the traces with the dark spots next to the battery are suspect.
Rub or scrape off the silkscreen carefully (a glasfiber pen is ideal for this, just beware of the small bits of glass fiber it leaves behind) and repair the traces if they measure 'open'.
Repairing such thin traces can be difficult, I tend to use very thin enameled wire (the soldarable type, also called Posyn wire), or so called 'Kynar' wire which you need to strip first (quite tricky).
Use flux to make the solder adhere better to the trace remnants.
 
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