RiscPC600 with StrongArm

Arc/RPCs, peripherals, RISCOS operating system & ARM kit eg GP2x, BeagleBoard
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eisdielenbiker
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RiscPC600 with StrongArm

Post by eisdielenbiker » Tue Oct 22, 2019 4:46 pm

Today I happened to get a 'German' StrongARM machine finally. I am hesitant to power it up for obvious reasons from the attachments.
It is battery leaking of course. Are there any experience, suggestions or predictions available ? What is to be done best next ?

Perhaps you can also help identifying what that machine is built of ?

I might have noticed a StrongArm-200MHz-card, right ? Some I-cubic Ethernet adapter with RJ45 and BNC ?
What is this very small board vertically seated that only connects via a handfull of pins to the main PCB ?
It has a grey bunch of some more wires leading to the main PCB like some audio device.
Where is the hard didsk drive supposed to be located ? Is it SCSI or IDE internally ?
However there is an additional Morley SCSI-Podule and an external SCSI CD-ROM drive supplied.

Thanks and regards
Mark
Attachments
B2004471.jpg
B2004470.jpg
B2004468.jpg
B2004467.jpg
B2004465.jpg
B2004464.jpg
A3010 4MB , A7000, A420

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SarahWalker
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Re: RiscPC600 with StrongArm

Post by SarahWalker » Tue Oct 22, 2019 4:54 pm

I might have noticed a StrongArm-200MHz-card, right ? Some I-cubic Ethernet adapter with RJ45 and BNC ?
Yep.
What is this very small board vertically seated that only connects via a handfull of pins to the main PCB ?
Looks like a 16-bit sound card. Early RiscPCs only supported 8-bit audio on the motherboard.
Where is the hard didsk drive supposed to be located ? Is it SCSI or IDE internally ?
Hard drive is under the 5.25" & floppy bays. The motherboard interface is IDE, though in your case the drive may be SCSI.

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eisdielenbiker
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Re: RiscPC600 with StrongArm

Post by eisdielenbiker » Tue Oct 22, 2019 7:43 pm

What is about the video RAM ? Is it the orthogonally mounted module with the big capacitors isn't ist ?
Other two module at 45 degrees are main RAM I think.
V-RAM looks a little bit furry though. Is there a pitfall upon removing and re-inserting it ?
thanks
Mark
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danielj
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Re: RiscPC600 with StrongArm

Post by danielj » Tue Oct 22, 2019 7:43 pm

SIMBO wrote:
Tue Oct 22, 2019 7:30 pm
take the pcb out the case and clip off the grim... cell
wash with water and a soft tooth brush the area around the cell thats discoloured
then use spot treatment acetic acid BP not vinegar..!!! and some fibre glass pen to clean any crud etc
Distilled malt vinegar is to all intents and purposes JUST dilute acetic acid. It is fine to use and easily to get hold of. Don't use wine vinegar, don't use cider vinegar, don't use raspberry vinegar, don't use brown malt vinegar, don't use lemon juice. It's the well accepted method of cleaning up battery spills. It won't damage anything, and I say this having taught Chemistry A-Level.

I'd also recommend against using a new NiCd battery - they're not easy to get hold of and cadmium is horribly toxic. NiMH is fine.

d.

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Re: RiscPC600 with StrongArm

Post by danielj » Tue Oct 22, 2019 7:44 pm

eisdielenbiker wrote:
Tue Oct 22, 2019 7:43 pm
What is about the video RAM ? Is it the orthogonally mounted module with the big capacitors isn't ist ?
Other two module at 45 degrees are main RAM I think.
V-RAM looks a little bit furry though. Is there a pitfall upon removing and re-inserting it ?
thanks
Mark
Pull it out and again, neutralise the battery spill with your acid-of-choice, and rinse it off. It pulls directly upwards.

d.

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eisdielenbiker
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Re: RiscPC600 with StrongArm

Post by eisdielenbiker » Wed Oct 23, 2019 6:04 am

I have already cleaned an Amiga 4000 mainboard some half a year ago. This one was also completely dismantled and i will do the same with this nice machine here. The sub board just look pristine in my opinbion. Some capacitors should be replaced in the long run nothing more. On the Amiga board I had used compressed air, electronics cleaner, distilled water soaking , acid soaking and again distilled water and compressed air to clean it. IPA is my main off the shelf cleaner anyway. Left it settle for 24 hours in a warm good vented place. BUT I noticed that some heavy crystallistion of salt did not come of in places like via holes or the casual leg of an IC. In the end the ICs leg was broken and the vias needed to be redone soldering with wire (which did a helpful guy for me). Now it runs again.
This RiscPC indeed looks not so bad and the pcb looks not as delicate as the Amiga's. Keeping fingers crossed. Will be back next week, probably with results. I have also been incolved into chemistry a lot in my early days. There should be som litmus flying around in the attic.
Do you opt for or against distilled water in first place ? It is somehow aggressive as it is hungry for minerals. But that just should do good in getting salts removed, won't it ?

Looking forward to running a RiscPC. I so much like the A7000 so far...but it is a little naked for lacking network, video capabilities and hard disk speed. Pure CPU power is still impressive. I had a contemporary 486 at 66 Mhz to fiddle around with Acorn disc formats and others. It was just rubbish I had to get rid of soon again.

Mark
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danielj
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Re: RiscPC600 with StrongArm

Post by danielj » Wed Oct 23, 2019 6:22 am

Distilled water has nothing dissolved in it, so is very good at not leaving a residue behind. Soaking/not agitating it is probably the reason you ended up with crystals as nothing got washed away propertly, really needs rinsing under running water. You can use tap water then do the final rinse with distilled. If you're in a very soft water area then you can probably get away with just tap water.

Compressed air can run the risk of making static and frying ICs. The IO chip on the riscpc is really sensitive to static.

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Re: RiscPC600 with StrongArm

Post by danielj » Wed Oct 23, 2019 1:04 pm

Just to note, SIMBO requested all posts to be deleted and account to be deleted.

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Re: RiscPC600 with StrongArm

Post by eisdielenbiker » Thu Oct 24, 2019 10:31 am

..strange things going on ....
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Re: RiscPC600 with StrongArm

Post by eisdielenbiker » Sun Nov 10, 2019 7:39 pm

I have cleaned the battery area using warm soapy tap water with a smal soft brush. Then I rinsed it clean with tap water and applied a vinegar solution of about 15 percent acid. This one I rinsed and brushed again with warm tap water after about 20 minutes. Finally I soakead and rinsed the pcb area with deionized water and blasted it dry as good as possible with compressed air. In the end I had to appply some glas fiber brush, a very fine scalpel and needles. You see the result here and obviously my camera is seeing better than my ageing eyes. However I have checked the pcb and VIAs in the affected area. There are some obvious problems I should fix before starting the machine up again:
(marked with yellow numbers in the first picture)
1) Should this T-junction join the 2 resistors with the one transistor leg ? And the other ends of the resistors should connect to the nearby VIAs, I think
2) this VIA is the only dead one I have detected. Should it connect to the capacitor nearby/above ?
3) There is no continuity between no.3 VIA an that brownish resistor (?) Should there be a connection ?
IMG_20191110_194234.jpg
This is the rear side of the PCB. There are still greenish residues I did not notice until now :-(
IMG_20191110_194913.jpg
I guess I will soak the not so perfect greenish VIAs in some oily,greasy corrosion inhibiting fat or oil to prevent further damage. It is just what did ever good to my English cars starting to rust. You have got to exclude water and oxygene to stop it going further.


BTW.
This is what the board looked like this morning before desoldering the battery:
IMG_20191110_130911.jpg

Comments and hints are very much appreciated. Thanks!
Mark
A3010 4MB , A7000, A420

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