ACA620 locking up when full memory is addressed

[MagerValp]

That's really great news, I'll see if it fixes my ProTracker freezes too.

[turrican9]

When using the ACA 620 in a closed case it gets very hot. Yesterday I was running it for several hours and I could feel the Amiga 600 was very hot on the underside (under where the CPU is located). I then took it appart and could feel the ACA 620 was very hot. This is not very strange as the backplate on the keyboard is trapping the rising heat coming from the ACA 620. It is made to operate like this, but heat sink or a fan would be a smart thing for longevity one should think. Everything was rock solid nontheless as long as the grounding wire is in place.

I would be very interested to hear from other people that have problems with the ACA 620 Rev.2 if using a grounding wire cures it. If so, this should be reported to Jens. There is no doubt in my mind that this product should have been shipped with a grounding wire and instructions. Products like the Indivision ECS Scandoubler is shipped with a grounding wire. But looks like the ACA 620 needs it more. I will take a picture of how I made my grounding wire and update later.

Update: I measured continuity from the grounding holes on the ACA 620 (minus the one that is not connected to the other ones. See pic below) without the grounding cable installed it still had continuity so it's obvious the ground connection through the pins on the CPU is not good enough. That is why it's important to make a more solid grounding like I have in the pictures below. Make sure it makes proper contact on both ends. And I doubt this has anything to do with me not making proper contact when installing the ACA 620 as I have verified this in two different A600 revisions now. Both show the excact same symptoms without the grounding cable installed. And by searching the web alot of other people have the excact same problems. It is however very important to give the ACA 620 a firm (somewhat hard so the motherboard gets bent a bit while pushing) push with your thumb in each corner. As stated earlier if it's not properly installed you will not be able to boot, and to check if it sits firmly with good contact I found that lifting the Amiga on the left side about 1cm from the table then dropping it would confirm if it was properly seated. If it crashes after doing this then go in and push firmly (Somewhat hard) on each corner (corners of the square that goes over the CPU on motherboard) until you hear it snap in place.




Also, the hole to the left marked with an X I could not measure any continuity with the other holes (ground points) using my multimeter. So I would not use that one. Oh, and I'm holding my finger over a Kickstart 3.1 ROM from amigakit. It has a serial number. I guess it does not matter, but I did it anyway. Also, softloading kickstart 3.1 works fine with the ACA 620. Did it in my Rev.2D Amiga 600 which has the original kickstart (2.05?).

[turrican9]

So after extensive testing I have found that the system will overheat to a point I can make some of the larger games like Flight of the amazon queen crash (black screen) on loading or quiting. This product simply makes the Amiga 600 overheating inside. It get's way to hot. Installing a 50mm fan in the top part of the chassi, where the grill is and making it draw out the hot air will solve this problem completely. Grounding wire is still the primary fix and made it very stable but without a fan it get's way to hot. I can only imagine how much of a problem this would be in hotter places or on a hot summer day.

I will post pictures of the fan mod later. It was an old 50mm fan I found which I used in the late 90s for various PC projects. I have ordered two modern, more silent 50mm fans which I will use instead. This product should have not only shipped with a grounding wire, but also with heatsinks. I still feel that all the hot air needs to be drawn out of the case because this will probably affect the longevity of the hardware. I can only guess, but putting my hand on the underside (where the CPU and ACA 620 is located) of the chassi it must have been 55 - 60 Celcius there. And that was the outside of the Amiga chassi with a room temp of about 23 Celcius. After adding the fan it felt like maybe 35 to 40 Celcius in the same spot.

Update:

[Amiga1992]

Interesting about the grounding wire. So the risers/bolts you have are not enough to ground the unit?

After returning my unit for replacement, which fixed the original problem of this thread (the unit was faulty), and having some more issues with the unit snapping out of place on transit and getting those risers from Jens, I have to say I have noticed no problems with my A600, but I haven't stress-tested it much to be honest.

I would really hate to have to add a fan to my system, the noise is annoying. My A1200 has a fan and it annoys me enough.

edit: I realize you only have one bolt to attach the grounding cable. If you write to Jens he might be able to send you the risers he sent me. I think this unit should have been delivered from factory with those risers, to make up for possible disconnection issues and the grounding.

[turrican9]

Originally Posted by Akira

Interesting about the grounding wire. So the risers/bolts you have are not enough to ground the unit?

After returning my unit for replacement, which fixed the original problem of this thread (the unit was faulty), and having some more issues with the unit snapping out of place on transit and getting those risers from Jens, I have to say I have noticed no problems with my A600, but I haven't stress-tested it much to be honest.

I would really hate to have to add a fan to my system, the noise is annoying. My A1200 has a fan and it annoys me enough.

edit: I realize you only have one bolt to attach the grounding cable. If you write to Jens he might be able to send you the risers he sent me. I think this unit should have been delivered from factory with those risers, to make up for possible disconnection issues and the grounding.

Hi,

what do you mean by risers? Pictures? I made this grounding wire myself. Honestly the heat that is generated inside the Amiga 600 when the case is closed is not healthy in my opinion. I have ordered a more silent 50mm fan now. I simply will not take my chances of not using a fan to draw out the hot air. This product is a very nice upgrade for the Amiga 600 as it is not very expensive and just strong enough and has enough mem to WHDLoad about every ECS/OCS game. But I feel it has not been tested enough prior to it's release and should come with a grounding wire and a small heatsink at least. I was an overclocking enthusiast from the mid 90s and outwards and have a great deal of experience with cooling and stuff, and when using the ACA 620 within an enclosed case I can safely say that it's overheating the Amiga 600.

If people want to take their chances running this with no cooling it's up to them, but for me there is no doubt I will use a fan to draw out the hot air. I'm not very happy using a fan in the Amiga 600, but I want to keep it safe. Oh, and I'm feeding the fan from the +5 volt rail which is strong on the Amiga. + 12v makes a fan of this size too noisy and +5v will run it fast enough to draw out the hot air.

[bubbob42]

Jens supplies the aforementioned screws with ACA620 since Rev2. They provide even better grounding than your wire. The non-ground hole in the PCB triggers overclocking together with the do-not-close-jumper.

I use two fans with my A600, the bigger one is switched on in overclocking mode automatically. Unit is rock stable.

Edit: more info here http://www.a1k.org/forum/showthread....524#post721524

[turrican9]

Originally Posted by bubbob42

Jens supplies the aforementioned screws with ACA620 since Rev2. They provide even better grounding than your wire. The non-ground hole in the PCB triggers overclocking together with the do-not-close-jumper.

I use two fans with my A600, the bigger one is switched on in overclocking mode automatically. Unit is rock stable.

Edit: more info here http://www.a1k.org/forum/showthread....524#post721524

I feel a bit stupid now. It came with 2 screws and a plastic part for one of the screws to go through. I never understood what these screws was for and I found nothing in the documentation. I even tried to look if some of the grounding holes on the ACA 620 would line up with holes on the motherboard and didn't see anything. However, after reading this I took a second look. Two of ACA 620's grounding holes lined up with two of the HD cage holes in the motherboard. I have now installed both screws and will be testing with no fan. I will keep the grounding wire I made in addition to these screws.

Thanks for the help

[bubbob42]

I'd recommend keeping one slow running 40mm fan inside the case. You will barely hear it, since you're going to use it as a games machine anyway. Both ACA620 and parts of the PLCC-type ECS chipset in the A600 get rather hot and a bit of airflow won't hurt.

I built a fitting trapdoor cover for this machine - if you have access to a 3D-printer, you can download the 3D-model here: http://www.thingiverse.com/thing:338598

[turrican9]

Originally Posted by bubbob42

I'd recommend keeping one slow running 40mm fan inside the case. You will barely hear it, since you're going to use it as a games machine anyway. Both ACA620 and parts of the PLCC-type ECS chipset in the A600 get rather hot and a bit of airflow won't hurt.

I built a fitting trapdoor cover for this machine - if you have access to a 3D-printer, you can download the 3D-model here: http://www.thingiverse.com/thing:338598

Yeah, I have two small fans on the way and will probably install one of them running on the +5v rail.

Don't have access to a 3D printer. Really nice 3D printout there. Without the 3D printer I could just remove the bottom trapdoor to get ventilation that way. BTW, after I installed the two grounding screws I have had no trouble. Been running for many hours now.

[Amiga1992]

Originally Posted by turrican9

I feel a bit stupid now. It came with 2 screws and a plastic part for one of the screws to go through.

That's alright mate, don't!
V2 didn't come standard with these screws by the way, I had to ask for mine. Maybe they do now but at some point, I guess when V2 first appeared, they didn't come de-facto.

For me they were essential, since the ACA620 was snapping out of the 68000 every time I transported my computer to a gig. Now it works great.

Overheating COULD be an issue in hot climates, I would think. At a gig, with very strong lights pointing at the stage, I noticed some problems with the ACA620. But it could have been the grounding issue magnified by temperature.

[mr.spiv]

Seemed to do the thing.. been running stable for few hours now. (slow testing cycle since the ACA620 was in void somewhere between UK and US past 14 months..) Time will tell but the board has never run this long.

Originally Posted by bubbob42

You should try to strengthen the card's ground connection by connecting the small holes to the motherboard. drive small screws though the two holes into the holes for the original harddisk bracket.

This fixes stability issues with some boards.

Edit: Don't use too much force while tightening the screws.

[turrican9]

Update from me on the ACA 620. Since I put the grounding connections that came with the card in place I removed my custom ground cable and also removed the fan I had installed. Everything has been rock solid. No crashes or overheating.

[Amiga1992]

I haven't had a problem either, the unit doesn't dismount from the CPU and I hace no issues at all!

[TjLaZer]

I didn't get the screws or grounding cable. I sent Amikit an email asking if I can get them since I'm having locking up issues

[mr.spiv]

those screws do not cost too many pennies.. just get few from "anywhere". I used philips M2x12mm sized screws.

Originally Posted by TjLaZer

I didn't get the screws or grounding cable. I sent Amikit an email asking if I can get them since I'm having locking up issues

[turrican9]

Originally Posted by TjLaZer

I didn't get the screws or grounding cable. I sent Amikit an email asking if I can get them since I'm having locking up issues

Yeah, those grounding screws are very important. Without them my system would not be stable at all. At the time I didn't understand what these screws was for. I just left them in the package. I don't think the documentation said anything about them either. But thankfully this forum helped me understand. They both ground the card and secure the ACA 620 for a better connection to the CPU. I also had to screw the groudings pretty tight to get good enough connection to the CPU. I had to screw it until the card started bending a bit. And even then I had to tighten a bit more to make a good and stable connection to the CPU.

[Amiga1992]

YEah you gotta tighten it til it naturally stops moving (the card WILL bend a bit) but not after that. Don't over screw it or it might break. If you have to apply force, you're not doing it wrong.

[DesktopDynamite]

Read all posts here and here is my update:

I bought the ACA620EC second hand and was OCed to 25mhz by previous owner.

Then it was sold to another before me, where he removed cooling parts before selling it to me.

I have sent an e mail to Jens and amigakit where previous owner bought this card from.

Card is ACA620EC (so yes it is rev 2)

Here is my email to Jens/icomp.de
"
Dear sir/madam,

Me and other users have a query regarding missing stuff from the ACA620EC package.

The story goes likes this, I have the ACA620EC bought as used.

Previous owner bought it fromamigakit.com, where he states that he only received the accelerator card without the stuff which MUST have been included.

These are as follows:

- mounting screws [to tighten the card on top of A600 CPU]

- white plastic pieces [used with the screws mentioned above]

- ground wire

All of the above are missing, where I have ordered another one from which included all of these.

Why are these missing ? And if so can you help me by stating the screws size needed ? or perhaps ship me the missing parts?

Before sending this mail to you, I have asked the same query toamigakit.com

Hope I receive an answer to my query, as many other did complain about this. Me and others have asked about this in many forums, facebook groups etc, no success.

Please help, I want to tighten the ACA on the A600 as by excess heat etc, it comes off, so it is not secure.

Thanks in advance,
"

First reply from Jens here;
"
Hi,

the contents of the box have been changed over the course of availability of the card. A grounding wire was never included, and the two screws and white plastic spacer were added later, as it became obvious that some A300/A600 boards require extra grounding, which is provided by the screws.

So please note that while the screws do provide mechanical stability, they are mainly required for adding grounding.

ciao,
--
Jens Schönfeld
"

And then I asked about screw size as he forgot to answer that part. So here is his answer:

" Hi,

ACA620EC screws are 2.2x13mm DIN 7981. Only available in stainless steel in these dimensions.

ciao,
--
Jens Schönfeld"

Now awaiting screws and plastic standoffs from eBay.

Standoffs link: https://rover.ebay.com/rover/0/0/0?m...2F261421941761 (chose M2, first one from the drop down list)

Screws from here:
https://rover.ebay.com/rover/0/0/0?m...2F322623461454 (chose number 2, 2.2mm and 13mm as suggested by Jens)

Once they arrive I will update you.

Note I have the first revision 1 of the A600 (A300 rev 1) along with A604n 1Mb trapdoor expansion.

I need further advice on how to proceed in fitting a CPU fan (maybe switched) and need link to find a quiet CPU fan plus instructions on how to use the mentioned 5v rail.

As for heatsink I may use a small extra one which I got from a raspberry pi case.

Thanks in advance

Sent from my F3111 using Tapatalk

[TjLaZer]

I finally secured my card as it seems to be stable! It use to lock up after a few min, even with case off. Now I need to attach my mini fan and tap for power. Where else is a good place to get power other than the floppy power lead?

I tried with M2 screws and they were way too thick, would not screw into HD mounting holes. Found some smaller screws, more like 1.7mm not sure, and they worked great.

[mr.spiv]

Originally Posted by mr.spiv

Got a new CF adapter (V.H0 whatever). When the CF card is plugged in I cannot get past early stages of boot. Without CF card A600 runs for a while. With no CF adapter at all.. rock solid. The new CF adapter + CF card and ACA620 turned off.. rock solid.

Sorry again for necromancing an old thread. I went back to install ACA620 again into my A600 (no ACA shown in this pic, tho).. Some bits have also changed since last time. I switched from Kingston (the CF brand that came from Amigakit originally) to SanDisk and tadaa.. the trouble maker runs hot but stable for hours. I am puzzled Anyway, some more testing ahead and if this CF switch solves my freezing problem I don't really care what happened with the orientation of planets whatsoever that caused it..

The content of CFs is equivalent i.e. just 'dd'ed images between cards.