A3000 power on test check error

discuss the archimedes & risc pc, peripherals and risc os/risc os on pi
jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Tue Mar 24, 2020 10:19 pm

Hi All

Just tried the RAM Test ROMS-here is a screenshot-
a3000 test roms.jpg
As you can see-there is finally visible text along with a pattern displayed in columns. I was able to use the keyboard to choose option 2 (Cyclic Memory test). This is the first time I have at least been able to confirm there is any keyboard functionality.
From what I can see, it would appear what is being written to memory and read back is different.
However I am no wiser on what to try next!

Does anyone have any suggestions?

Thanks.

User avatar
IanS
Posts: 1199
Joined: Mon Aug 31, 2009 7:02 pm
Contact:

Re: A3000 power on test check error

Post by IanS » Tue Mar 24, 2020 10:49 pm

jpagen wrote:
Tue Mar 24, 2020 10:19 pm
Just tried the RAM Test ROMS-here is a screenshot-
...
Does anyone have any suggestions?
Looks like D16-D19 are being read incorrectly, That corresponds to IC24. Check the connections to all the pins and trace the data pins back to the ARM via R50,R115,R116,R117.

steve3000
Posts: 2158
Joined: Sun Nov 25, 2012 12:43 am
Contact:

Re: A3000 power on test check error

Post by steve3000 » Wed Mar 25, 2020 9:02 pm

Great to see the ROMs worked!

As Ian says, this helps pin down to IC24.

Let us know how you get on testing connections, but also if you have a 4mb upgrade, it would be worth trying this to bypass the onboard RAM (in case the fault is IC24 itself).

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Wed Mar 25, 2020 9:25 pm

Thanks IanS and Steve3000 for your help. I will check the traces when I get a bit more time...probably the weekend.

I did try my 4MB ram card and it is looking more hopeful now. The screen corruption has gone The test roms aborted after about 10 mins or so though. I bought the 4MB board on line recently so not sure if the message highlights a problem with the 4MB board or something else:-
a3000 25 Mar 2020.jpg


I also tried swapping in my RISCOS3.11 roms again while the 4MB board was installed to see if that provided any more info. This time I got a different fault code &00000219. Checking on https://www.retro-kit.co.uk/page.cfm/co ... re-errors/
gives the following explanation
  • ROM failed checksum test
    ARM 3 fitted/ARM ID read and not ARM2
    Long memory test performed
    Self-test due to power-on
Any words of wisdom is much appreciated!

Thanks

steve3000
Posts: 2158
Joined: Sun Nov 25, 2012 12:43 am
Contact:

Re: A3000 power on test check error

Post by steve3000 » Wed Mar 25, 2020 10:03 pm

Interesting that you’re getting a ROM checksum error. I assume you’re using original ROMs, not EPROMs? If so, these should not fail checksum.

So it’s possible one or more high address line tracks are corroded to your ROMs, but I can’t help wondering if something simpler could be the issue, such as your ARM3 socket? Have you tried reseating the ARM3 board (to help remove any oxidation between the socket pins and riser board) or switching back to ARM2 (if you have the original chip and extractor tool?)...

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Wed Mar 25, 2020 10:30 pm

Thanks Steve3000!

yes using the original Riscos3.11 ROMs.

I have never removed the ARM3 board. I have gently pressed down on it to see it was loose but it feels secure. I could see if I can remove it and re-inserting if the connections are oxidised Unfortunately I don't have the ARM2.

I will also try the original RISCOS2 ROMS tomorrow. I should highlight that when I originally cleaned the board following the battery leak, there was some slight green corrosion around a few of the RISCOS pins. I cleaned the roms and sockets but perhaps I should replace the sockets which will also allow me to see if the traces underneath are affected.

Thanks

User avatar
myelin
Posts: 852
Joined: Tue Apr 26, 2016 10:17 pm
Location: Mountain View, CA, USA
Contact:

Re: A3000 power on test check error

Post by myelin » Thu Mar 26, 2020 4:57 pm

Unfortunately you won't get the second part of the ROM checksum error test unless you have a POST box connected, but there's an easy way to see if any of the address lines are bad, if you have a scope or logic analyzer: When an ARM2 or ARM3 chip is in reset, it'll execute NOPs and page through its entire address space. So if you hold down the reset button, you should see a square wave on every address pin on the ROMs. If this is missing anywhere, that's the wire to fix.

I recently fixed three A3000 boards; two of them had breaks in the tracks between the address buffers (IC29, IC30, IC31) that generate LA2-21 from A2-21, and one of them had a break in a track between the ARM2 and the address buffers. So once you find your pin without the expected square wave, buzz it out between the ROM pin and address buffer, and from the address buffer to the CPU.

Note that you could also have a disconnected pin on one of the ROM sockets, so you'll have to check this on every address pin on every ROM socket to be sure.
SW/EE from New Zealand, now in Mountain View, CA, making BBC/Electron hardware projects for fun.
Most interesting: Arcflash, FX2+PiTubeDirect Tube/Cartridge adapter, USB cart interface.

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Thu Mar 26, 2020 10:03 pm

steve3000 wrote:
Wed Mar 25, 2020 10:03 pm
Have you tried reseating the ARM3 board (to help remove any oxidation between the socket pins and riser board)
I took a look at the ARM3 board today. On removal I could see some slight green corrosion in a few pins which came off easily with a little white vinegar , rinsing with water and finally a little IPA. I was surprised to see any green corrosion as I did not have any visible corrosion on any of the surrounding tracks. After allowing to dry and re-inserting, I switched on and was presented with a black screen and a steady green led with no flashing sequence :shock:

I removed the ARM3 and reseated before trying again and.....
20200326_210706.jpg
:D :D :D :D

Thanks Steve3000 for the suggestion =D>

Sorry for the bad picture-took it on my phone. It is BW as still using the monochrome video on a TV. The Moiré effect is not visible.
  • Not sure if I should still try and remove the ROM sockets now I can boot-I think probably best left alone.
  • The keyboard seems to be working fine so the conductive paint repair to the ribbon seems to have done the job.
  • The mouse is not working 100% though. Sometimes I can move in the x-axis but y axis is not working at all. Buttons sometimes work. I may try removing the mouse socket and giving it a good clean-I can certainly see some green corrosion, unless anyone has any other recommendations?
  • I would like to connect a new CMOS battery in the external compartment near the mouse socket too.
  • Strangely the start-up beep is distorted on RISCOS3.11 but I also tested on RISCOS2 and it was fine. I am assuming a bad connection on one of the speakers
I have just removed the onboard SRAM battery from my BBC Model B..I don't want to go through this again anytime soon!

Thanks to everyone for the advice throughout this thread. Your suggestions kept me going. IanS, I will still take a look at the tracks you suggested to try and figure out why I cannot boot without my 4MB board. Myelin did not get to your suggestions until after I booted successfully but thanks for taking the time to comment.

Will post any progress if it is of interest.

User avatar
myelin
Posts: 852
Joined: Tue Apr 26, 2016 10:17 pm
Location: Mountain View, CA, USA
Contact:

Re: A3000 power on test check error

Post by myelin » Thu Mar 26, 2020 10:09 pm

Congratulations! It's a good feeling when that desktop appears!
SW/EE from New Zealand, now in Mountain View, CA, making BBC/Electron hardware projects for fun.
Most interesting: Arcflash, FX2+PiTubeDirect Tube/Cartridge adapter, USB cart interface.

steve3000
Posts: 2158
Joined: Sun Nov 25, 2012 12:43 am
Contact:

Re: A3000 power on test check error

Post by steve3000 » Thu Mar 26, 2020 11:20 pm

jpagen wrote:
Thu Mar 26, 2020 10:03 pm
I removed the ARM3 and reseated before trying again and.....
That's brilliant, well done - and welcome back to your A3000 :D
jpagen wrote:
Thu Mar 26, 2020 10:03 pm
Thanks Steve3000 for the suggestion =D>
No problem, glad to help! It was a bit of a hunch, the change in errors you were seeing just didn't add up...and your A3000 is one of only a few with an ARM3...

Also pleased to see those RAM test ROMs in action on a real RAM fault!

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Sat Mar 28, 2020 7:08 pm

myelin wrote:
Thu Mar 26, 2020 10:09 pm
Congratulations! It's a good feeling when that desktop appears!
Thanks! Yes it was a great relief!
IanS wrote:
Tue Mar 24, 2020 10:49 pm
Looks like D16-D19 are being read incorrectly, That corresponds to IC24. Check the connections to all the pins and trace the data pins back to the ARM via R50,R115,R116,R117
I traced the pins from IC24 through R50,R115,R116,R117, and then traced R50,R115,R116,R117 through to the ARM3. There was continuity. Also checked the R50,R115,R116,R117 resistance and they all seemed fine. I have to say the board looks clean in this area with no signs of any corrosion. I assume this means my IC24 needs replacing? I found the Service Manual on line which states the part as IC DRAM 256Kx4 120n 20ZIP. Did a search but could not find any for sale. Does anyone know where I may find one?

According to the service manual the 2MB board uses the same chips. Does anyone know if all 2MB ram boards would use the same chips or just Acorn? I have one by Watford Electronics which I guess I could try sacrificing if there are no other options.

Mouse investigation
Desoldered the socket (that really didn't want to come off!) and watched it fizz in some white vinegar for a while so it definitely needed a clean
Also cleaned the board and resoldered the socket checking continuity along the mouse cable after opening up the mouse
Now I have movement in the y axis and nothing in the x axis! I assuming a bad connection somewhere but I checked continuity from each wire in the opened mouse through to the points on the back of the motherboard. I see there are PS2 mouse adaptors so maybe try one of those which would help pin point if this is an issue with my mouse.

Found another issue. Apart from the power led, the other leds(shift lock, num lock etc) on my keyboard aren't working. I am guessing this is another bad connection somewhere

Any suggestions on any of this would be appreciated. I also found this discussion on mouse issues so will take a look viewtopic.php?f=16&t=12772

Thanks as always!

Kazzie
Posts: 1365
Joined: Sun Oct 15, 2017 8:10 pm
Location: North Wales
Contact:

Re: A3000 power on test check error

Post by Kazzie » Sat Mar 28, 2020 8:27 pm

jpagen wrote:
Sat Mar 28, 2020 7:08 pm
I assume this means my IC24 needs replacing? I found the Service Manual on line which states the part as IC DRAM 256Kx4 120n 20ZIP. Did a search but could not find any for sale. Does anyone know where I may find one?
Is that the same chip as used in the A4x0/1 series for on-board RAM expansion? If so, I've got a few spare somewhere from when I maxed-out my machine.
BBC Model B 32k issue 7, Sidewise ROM board with 16K RAM
Archimedes 420/1 upgraded to 4MB RAM, ZIDEFS with 512MB CF card
Acorn System 1 home-made replica

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Sun Mar 29, 2020 9:58 am

Kazzie wrote:
Sat Mar 28, 2020 8:27 pm
Is that the same chip as used in the A4x0/1 series for on-board RAM expansion?
Thanks Kazzie. Checked the service Manual http://chrisacorns.computinghistory.org ... R140SM.pdf
They seem to have the same part number (0704.118)

Kazzie
Posts: 1365
Joined: Sun Oct 15, 2017 8:10 pm
Location: North Wales
Contact:

Re: A3000 power on test check error

Post by Kazzie » Sun Mar 29, 2020 3:54 pm

jpagen wrote:
Sun Mar 29, 2020 9:58 am
Kazzie wrote:
Sat Mar 28, 2020 8:27 pm
Is that the same chip as used in the A4x0/1 series for on-board RAM expansion?
Thanks Kazzie. Checked the service Manual http://chrisacorns.computinghistory.org ... R140SM.pdf
They seem to have the same part number (0704.118)
Right, now all I have to do is find my spares!

I'll have a dig through my various boxes of parts, and get in touch.
BBC Model B 32k issue 7, Sidewise ROM board with 16K RAM
Archimedes 420/1 upgraded to 4MB RAM, ZIDEFS with 512MB CF card
Acorn System 1 home-made replica

User avatar
daveejhitchins
Posts: 5494
Joined: Wed Jun 13, 2012 6:23 pm
Location: Newton Aycliffe, County Durham
Contact:

Re: A3000 power on test check error

Post by daveejhitchins » Sun Mar 29, 2020 5:43 pm

Kazzie wrote:
Sun Mar 29, 2020 3:54 pm
Right, now all I have to do is find my spares!

I'll have a dig through my various boxes of parts, and get in touch.
You may just have the time for that search, now!

Dave H :D
Parts: UM6502CE, GAL22V10D, GAL16V8D, AS6C62256A, TC514400AZ, WD1772, R6522, TMS27C512, AT28C256
Products: ARA II, ARA III, ABR, ATI, AP6, MGC, AP5 . . .
For a price list, contact me at: Retro Hardware AT dave ej hitchins DOT plus DOT com

sP1d3r
Posts: 45
Joined: Fri Aug 23, 2019 2:40 am
Contact:

Re: A3000 power on test check error

Post by sP1d3r » Sun Mar 29, 2020 11:21 pm

Hi

I wondered if you'd seen the 'Very Dead A3000' post re: L7->8051 connection, also beware PS/2 to Quad adapters.

I bought one of the ones on eBay and although it worked for about 3-4 times, the mouse cursor froze and would only work after Power on/Delete until it's now frozen, see picture.
The PIC has 128B eeprom memory which I suspect is easily corrupted.
Attachments
WP_20200327_07_26_09_Pro (2).jpg

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Tue Mar 31, 2020 9:30 pm

sP1d3r wrote:
Sun Mar 29, 2020 11:21 pm
I wondered if you'd seen the 'Very Dead A3000' post re: L7->8051 connection
Thanks! No hadn't see that. Here is the link if anyone else is looking viewtopic.php?t=18126 I have continuity between L7 and the 8051 though and my mouse y axis is fine. Does anyone know where to look for the x-axis issue? I did have a broken trace between L7 and the Sk7 though but I repaired that some weeks back.

It sounds like pin 16 on SK7 could be a possible issue for the keyboard LEDs. I thought I had sorted the continuity issues when I replaced SK7 but will check again. Apart from the LEDs, the keyboard works fine. Unfortunately I need to keep removing the keyboard to test my progress and each time I do, it removes the conductive paint from my ribbon repair and I have to apply the paint again.

sP1d3r
Posts: 45
Joined: Fri Aug 23, 2019 2:40 am
Contact:

Re: A3000 power on test check error

Post by sP1d3r » Tue Mar 31, 2020 10:13 pm

:roll: The thing about repairing a vintage computer is that whilst your meter shows continuity when you test, when the board is powered up it might still not work properly if the signal path is degraded.
The kind of beep that you get is a clue, the probes need to be cleaned with IPA and contact with tracks & pins good.
You might consider getting a soldering practice kit, they're inexpensive. The right kind of flux for the job helps and a good iron also, like a T12 which can be found on Aliexpress etc. in kit form or pre-built with a variety of tips for a low price, good quality soldering wick is indispensable too.
Through-hole and surface mount soldering require different techniques, practice is the only way to progress.
Using a solder sucker with through-hole is essential but the recoil and positioning requires practice.
Every job is different and things like leaking capacitors and battery acid affect the removal and replacement of components, repairing mistakes can be difficult but like on 'Plan C's' video (he used Kynar wire to great effect) can save the day.

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Fri Apr 10, 2020 9:50 pm

Thanks sP1d3r for the responses.

I have been investigating further and tried another mouse to rule out problems with my mouse and get the same problem. ie no movement in the x axis. Actually I get a slight flicker in the x axis so clearly something is being read but no actual movement. Mouse buttons and y axis are fine.

I have spent quite a bit of time since my last post cleaning the traces again, re-soldering and checking all lines from the mouse socket. The multi-meter 'beep' sounds cleaner and all lines from the mouse socket through to the IC2, 0V and 5V check out as expected(with reference to the PCB diagram). One thing I did find is pin 5(xd) on the mouse socket has continuity to IC2 pin 26 (which I believe is correct) but also to pin 40 in IC2 as well. I could not see pin 40 referenced for IC2 on circuit diagram.

Does anyone know if IC2 pin 40 and pin 26 should both be connected to mouse socket pin5 ? Any other recommendations where to look? I am not sure what else to try.

Thanks for any advice!

Kazzie
Posts: 1365
Joined: Sun Oct 15, 2017 8:10 pm
Location: North Wales
Contact:

Re: A3000 power on test check error

Post by Kazzie » Sat Apr 11, 2020 5:37 am

jpagen wrote:
Fri Apr 10, 2020 9:50 pm
One thing I did find is pin 5(xd) on the mouse socket has continuity to IC2 pin 26 (which I believe is correct) but also to pin 40 in IC2 as well. I could not see pin 40 referenced for IC2 on circuit diagram.

Does anyone know if IC2 pin 40 and pin 26 should both be connected to mouse socket pin5 ?
Working from the A3000 datasheet, pin 2 on IC2 (8051AH) is part of Port 1, which is wired to the keyboard interface socket SK6. It shouldn't be connected to pin 26 and the mouse as well.
BBC Model B 32k issue 7, Sidewise ROM board with 16K RAM
Archimedes 420/1 upgraded to 4MB RAM, ZIDEFS with 512MB CF card
Acorn System 1 home-made replica

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Sat Apr 11, 2020 9:20 am

Kazzie wrote:
Sat Apr 11, 2020 5:37 am
Working from the A3000 datasheet, pin 2 on IC2 (8051AH) is part of Port 1, which is wired to the keyboard interface socket SK6. It shouldn't be connected to pin 26 and the mouse as well.
Thanks Kazzie
Just to clarify, it is pin 40 and pin 26 which appear to be connected on IC2, not pin 2 and pin 26.
Does anyone know(or can check their A3000) if pins 40 and 26 are supposed to be connected on IC2? I could not see pin 40 on the circuit diagram so I assumed it was unused.

Thanks

Kazzie
Posts: 1365
Joined: Sun Oct 15, 2017 8:10 pm
Location: North Wales
Contact:

Re: A3000 power on test check error

Post by Kazzie » Sat Apr 11, 2020 11:01 am

jpagen wrote:
Sat Apr 11, 2020 9:20 am
Kazzie wrote:
Sat Apr 11, 2020 5:37 am
Working from the A3000 datasheet, pin 2 on IC2 (8051AH) is part of Port 1, which is wired to the keyboard interface socket SK6. It shouldn't be connected to pin 26 and the mouse as well.
Thanks Kazzie
Just to clarify, it is pin 40 and pin 26 which appear to be connected on IC2, not pin 2 and pin 26.
Does anyone know(or can check their A3000) if pins 40 and 26 are supposed to be connected on IC2? I could not see pin 40 on the circuit diagram so I assumed it was unused.

Thanks
Apologies, that's what happens when I try to offer technical advice before 6 in the morning :oops:

Pins 20 and 40 aren't mentioned on the circuit diagram because they're the power supply pins - it's convention to leave them off circuit diagrams to concentrate on the more "interesting" pins. Pin 40 is the 5V supply pin, so that indicates your Xd mouse signal (pin 26) is shorted to 5V somewhere.

(Thankfully, that's a more reasonable fault than for it to be shorted to pin 2!)

Firstly, I'd suggest checking if there's continuity between the two with your mouse unplugged (in case you haven't already done so). If the short is still present, R576 is a 10k pull-up resistor between Xd and 5V, there may be a short bypassing that resistor. On the mouse socket, pin 6 (adjacent To Xd on pin 5) carries the 5V supply for the mouse, so that's another reasonable place to find a short.
BBC Model B 32k issue 7, Sidewise ROM board with 16K RAM
Archimedes 420/1 upgraded to 4MB RAM, ZIDEFS with 512MB CF card
Acorn System 1 home-made replica

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Sat Apr 11, 2020 3:13 pm

Kazzie wrote:
Sat Apr 11, 2020 11:01 am
Firstly, I'd suggest checking if there's continuity between the two with your mouse unplugged (in case you haven't already done so). If the short is still present, R576 is a 10k pull-up resistor between Xd and 5V, there may be a short bypassing that resistor. On the mouse socket, pin 6 (adjacent To Xd on pin 5) carries the 5V supply for the mouse, so that's another reasonable place to find a short.
Thanks Kazzie! You're right! :D R576 is showing 0 resistance and there is continuity between pin 5 and 6 on the mouse socket. There is nothing visible but I did remove the mouse socket to clean off the corrosion so I will remove and check again. Will report back with progress

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Sat Apr 11, 2020 5:08 pm

jpagen wrote:
Sat Apr 11, 2020 3:13 pm
I did remove the mouse socket to clean off the corrosion so I will remove and check again.
OK so I removed the mouse socket and the short between IC2 pin 26 and pin 40 is resolved. Checking the removed mouse socket and the short between pin 5 and 6 is within the mouse socket itself. :o I will try and fix it but does anyone know if a replacement mouse socket is still available? Did a search but could not find anything. Unfortunately got 3 via's to repair which disintegrated during removal of the socket. :(
Having to remove the socket twice was obviously too much for the old board to cope with!

Kazzie
Posts: 1365
Joined: Sun Oct 15, 2017 8:10 pm
Location: North Wales
Contact:

Re: A3000 power on test check error

Post by Kazzie » Sat Apr 11, 2020 6:21 pm

jpagen wrote:
Sat Apr 11, 2020 5:08 pm
jpagen wrote:
Sat Apr 11, 2020 3:13 pm
I did remove the mouse socket to clean off the corrosion so I will remove and check again.
OK so I removed the mouse socket and the short between IC2 pin 26 and pin 40 is resolved. Checking the removed mouse socket and the short between pin 5 and 6 is within the mouse socket itself. :o I will try and fix it but does anyone know if a replacement mouse socket is still available? Did a search but could not find anything. Unfortunately got 3 via's to repair which disintegrated during removal of the socket. :(
Having to remove the socket twice was obviously too much for the old board to cope with!
This may be what you need: https://uk.farnell.com/schurter/4850-29 ... /dp/152392

But take a close look to check it's the correct part,as I'm not speaking as a past buyer here.
BBC Model B 32k issue 7, Sidewise ROM board with 16K RAM
Archimedes 420/1 upgraded to 4MB RAM, ZIDEFS with 512MB CF card
Acorn System 1 home-made replica

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Sun Apr 12, 2020 9:45 pm

Kazzie wrote:
Sat Apr 11, 2020 6:21 pm
This may be what you need: https://uk.farnell.com/schurter/4850-29 ... /dp/152392
Thanks Kazzie

Looking at the technical document, that appears to be the right layout. However I managed to disassemble the original mouse socket and reassemble. The short is resolved and I have a fully functioning mouse :D I may order a new one as a backup while I can.

Next on the list is to figure out why the keyboard LEDs are not working but my A3000 is usable at last! Got a colour picture on a TV via SCART. :D

Also need to check the sound which is a little crackly.

I still have an issue with the on-board RAM. I have received a couple replacement chips but I'm reluctant to remove the IC24 while things are working with the 4MB board. Interestingly the RAM Test ROMs freeze after about 15 mins when checking the 4MB memory :?

A big thank you again to everyone for the help so far.

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Thu May 07, 2020 10:42 pm

Hi All

Continuing with my A3000 project.

Performed the sound mod viewtopic.php?t=13630 and fitted a Burr-Brown OPA4134PA viewtopic.php?f=16&t=11287
I made a recording from the headphone socket pre and post mod and It sounds significantly clearer off the headphone socket.

Also fitted a replacement CMOS battery in the external battery compartment

Still having issues with the RAM though. Running the RAM test ROMs with a 4MB expansion module just hangs after 15 mins or so. No error messages, just a single row of dots indicating test progress which hangs at the end of the first line. I am using a 4MB SIMM adaptor and have tried 2 different SIMMS with the same result. I am selecting 4MB option when running the test. Machine boots fine in to RISCOS 3.11 though

I still need to replace the IC24 (I have the RAM chip) but would really like to get the 4MB working. Would very much appreciate any advice!

Thanks

sP1d3r
Posts: 45
Joined: Fri Aug 23, 2019 2:40 am
Contact:

Re: A3000 power on test check error

Post by sP1d3r » Sun May 10, 2020 11:38 am

:-& Hi

Can you give some idea of how much usage your ARM 3 arc has had, also do you have any facts and figures relating to the power consumption of the CPU in relation to the standard ARM 2?

steve3000
Posts: 2158
Joined: Sun Nov 25, 2012 12:43 am
Contact:

Re: A3000 power on test check error

Post by steve3000 » Sun May 10, 2020 12:18 pm

jpagen wrote:
Thu May 07, 2020 10:42 pm
Performed the sound mod viewtopic.php?t=13630 and fitted a Burr-Brown OPA4134PA viewtopic.php?f=16&t=11287
I made a recording from the headphone socket pre and post mod and It sounds significantly clearer off the headphone socket.
Great modifications those ;)
jpagen wrote:
Thu May 07, 2020 10:42 pm
Still having issues with the RAM though. Running the RAM test ROMs with a 4MB expansion module just hangs after 15 mins or so. No error messages, just a single row of dots indicating test progress which hangs at the end of the first line.
Any evidence of the machine crashing during normal operation? E.g. if you leave a demo or game running? Or fill the memory with lots of desktop apps running?

jpagen
Posts: 41
Joined: Sat Feb 09, 2019 8:28 pm
Contact:

Re: A3000 power on test check error

Post by jpagen » Sun May 10, 2020 9:30 pm

steve3000 wrote:
Sun May 10, 2020 12:18 pm
Great modifications those
Thanks Steve3000-the first thread is yours and the 2nd one was Zarchos =D>

steve3000 wrote:
Sun May 10, 2020 12:18 pm
Any evidence of the machine crashing during normal operation? E.g. if you leave a demo or game running? Or fill the memory with lots of desktop apps running?
I had one crash but that may or may not be relevant. I will try filling the memory with apps and see what happens. I will need to wait a few days as I am waiting for some new SN74LS145N's(IC4/IC5). I had left these unchecked from the battery leakage since I started the project but I got around to removing them at the weekend. IC4 came off quite easily but IC5 would not move and I ended up having to cut the pins. There was some corrosion underneath IC5 which has been neutralised and socket added waiting for the new chip.

Post Reply

Return to “32-bit acorn hardware”