exxos's Atari, Amiga & retro forum

This was parked for a while - but I now had some time again to try it further so, here is an update:
So, currently TF536 is sitting in my A2000 via CPU relocator board. Original 68000 is removed from the socket.
Kickstart 3.1.4. Compact flash with only a pure WB 3.1.4 installation - not even the 68030.library installed.

TF536 boots from CF card just fine. However, the workbench hanged after about 1 minute even if nothing was done with it...
mouse pointer got stuck and Gurued right after that. Eventually the A2000 went into a reset loop where it then tried to boot again but got reset again in the middle of loading WB.
So, it looked like a overheating problem. The MC68030 didn't feel too hot - just warm - didn't do temperature measurements.
I added a heatsink with a thermal glue on to MC68030. It didn't seem to solve the problem.
I added a fan to cool the heatsink. That seemed to solve the problem. A2000 was powered on for several hours without issues.
I attached a picture I took from the MC68030 before attaching a heatsink. Cleaned with just IPA - didn't try acetone...
Funny thing is that this overheating problem only seemed to appear when workbench was running... I did have some 68000 demos running before adding a heatsink - the demos did run just fine - no Gurus or resets.
Can someone, perhaps recommend a certain software that would be pushing the 68030 to its limits so, I could see if it seems to be working fine?

... Now, looking at the picture of my 68030 - it looks almost as if there would be a transparent film covering the CPU and this would be peeling off from the left side...perhaps that is just an optical illusion...

If you can boot amiga test kit from floppy leave it running the ram test for a day or so.

https://github.com/keirf/Amiga-Stuff/releases

Ok - thanks, I need to do a longer RAM test with Amiga test Kit later...

For now - I attached my multimeter's thermocouple on to the CPU heatsink and run the Amiga test kit for about an hour (FAN was not used)
Temperature started from ambient 20 Celsius and very slowly rose to 29 Celsius after the first 40minutes and then stayed at that temperature for the rest of the time.

I then switched the A2000 of for a minute - temperature went down a bit to 28 Celsius - and then booted from CF card
to WB 3.1.4. Didn't do anything in workbench - just checked a few times that he mouse pointer is still moving.
--> Temperature started to rise about 1 degree / minute. It was about 36 Celsius when mouse pointer suddenly changed to "Busy pointer" - then after a minute the A2000 got reset... temperature at the heatsink was 37 Celsius then.
So, I guess WB is doing something in the background that causes a load in the CPU... I didn't notice any IDE activity (just tried to look at the LED in the CF adapter)...

If you have the option I would try a different 030.

Measure also the 5v rail at the TF... and check the temperature of the CPLD.

The voltage measured from PWR2 -pin at TF536 stays at about 5.15V.
Attached the thermocouple into the surface of CPLD. Temperature there seemed to reach about 38 Celsius.

Unfortunately this is my only MC68030... I'll try to dig if there is a tested working available to be bought somewhere...
-Thanks

tvoutila wrote: 17 Mar 2021 12:39 The voltage measured from PWR2 -pin at TF536 stays at about 5.15V.
Attached the thermocouple into the surface of CPLD. Temperature there seemed to reach about 38 Celsius.

Unfortunately this is my only MC68030... I'll try to dig if there is a tested working available to be bought somewhere...
-Thanks

Is possibly a bad cap. Did you build this yourself?

Yes, self-built TF536.
... Do you mean possibly a bad cap at C1 or C2 ? I believe those were the only caps I added to this pre-populated rev 2b -board.

tvoutila wrote: 17 Mar 2021 13:20 Yes, self-built TF536.
... Do you mean possibly a bad cap at C1 or C2 ? I believe those were the only caps I added to this pre-populated rev 2b -board.

I was actually thinking the caps under the CPU could be bad chinesium

aah - ok, you mean the ones shown in the picture...


I'll try to order some replacements for those and see if that helps.

Start by trying touching up the solder on them