A600 repair advice - Page 2

BennehBoy · 12 May 2021, 21:27

I checked that in circuit and it was reading good, cheers

solarmon · 12 May 2021, 21:32

Quote:

Originally Posted by BennehBoy

I checked that in circuit and it was reading good, cheers

On my A600, I had to remove (and replace) C611 to get it to boot.

BennehBoy · 12 May 2021, 21:54

Just rechecked it out of circuit and it seems to be OK.

BennehBoy · 13 May 2021, 12:27

Seems pretty stable now that I thoroughly flushed the reset circuitry area.

Next bits might need a new thread - shout if so.

I've made a copy of my TF536 CF card onto a spare SD card which I've put into the a600 with an SD2IDE adapter.

First hurdle was that it would hang at the wbload - pretty sure there were some 030 versions of files kicking about, so I used the 3.1.4 installer under winuae to refresh the install (I've also burnt and installed a 3.1.4 rom - all licensed btw).

It now boots fine, but CLI won't run - I've checked all the library versions etc and they match. Any ideas?

BennehBoy · 13 May 2021, 12:36

Never mind, found the problem, MUI.

BennehBoy · 13 May 2021, 13:40

And hit another issue, this time hardware....

With the 1mb chipram expansion fitted, the machine boots fine from IDE, but the floppy stops recognising disks, and the RMB no longer functions. The memory is detected OK - I 'think' when I first fired up the machine before the recap that I ran a successful mem test using Amiga Test Kit, but am not 100%.

Everything is fine without the expansion connected, but clearly memory is then super tight. (I've got an 8mb fast ram expansion on order).

Any ideas on what signalling from the trapdoor interferes with the above?

PS the trapdoor connector contacts are clean.

solarmon · 13 May 2021, 18:56

If you run a long memory test (over 100 rounds) on just the the expansion chip ram, does it pass or fail?

BennehBoy · 13 May 2021, 19:11

I'll need to run it with diagrom - will feed back.

solarmon · 13 May 2021, 19:20

Oh, I was confusing it with an A500 where you can boot with the expansion memory card disabled, then enable it for memory test.

But you can't boot from IDE and run Amiga Test Kit from that?

BennehBoy · 13 May 2021, 19:29

The floppy I have with Amiga Test Kit on is a bootable one that bypasses the OS and load binary...

Is Amiga Test Kit launchable from WB? Honestly don't know - and I need to muck about getting it onto the HD if so. Will have a mess with it after the gym.

solarmon · 13 May 2021, 19:37

Yes, in the Amiga Test Kit download zip file there is an ADF and a program file that can be run from Workbench.

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

You just now need to figure out how to get it on the HDD/CF (i.e. mount it in WinUAE emulation, or use PCMCIA/CF transfer, or use serial transfer).

BennehBoy · 13 May 2021, 21:15

Ah cool, I've been away from Amiga's since about 1994 so am having to relearn everything that I probably never knew in the first place

Copied it on with WinUAE, it's sat running through the tests now, no issues so far, but right mouse & floppy not working with the ram in - quite bizarre.

BennehBoy · 13 May 2021, 21:43

60 cycles and good so far

solarmon · 13 May 2021, 21:56

Not sure if this was already mentioned to be good, but check the +5V rail and see if the power supply is OK.

BennehBoy · 13 May 2021, 22:14

100 passes all OK, cancelled.

Mouse checks show the RMB is stuck on:

Floppy read test shows every sector bad

This has to be a bad line or poor buffering, surely? I just don't know enough about what these signals _should_ look like.

I've got a logic probe & DSO here if anyone has any thoughts about what to look at.

BennehBoy · 13 May 2021, 22:15

Quote:

Originally Posted by solarmon

Not sure if this was already mentioned to be good, but check the +5V rail and see if the power supply is OK.

Good call

solarmon · 13 May 2021, 22:26

I would check voltage rails getting to Paula, which the Right Mouse Button goes to, and also responsible for floppy data reads.

BennehBoy · 13 May 2021, 22:32

Well something is very wrong.

I have 3 Amiga PSU's here, all of which power my A500 just fine.

With the ram expansion in the system vcc is 4.2V!

Using an ATX supply it's 4.3V

With the expansion removed it's 4.4V

I measured VCC at the 555.

Popping the SD2IDE & card out ups the voltage again to 4.5V

Time to go study the power schematics....

I did remove/replace the line filter by the supply input to get more room to get at the caps, I don't think it got damaged, but if it had I'd expect full on failure rather than a supply drop...

The ATX PSU is rated at 600W

solarmon · 13 May 2021, 22:56

Yeah, that is definitely not good.

Just for testing, you can try powering the A600 through the floppy power port, to rule out anything with the normal power connector.

BennehBoy · 13 May 2021, 23:10

Even worse, 4.09V - And this is without the ram expansion or floppy connected.

The ATX supply is putting out 5.11V without a load.

13 May 2021, 13:40	#26
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	And hit another issue, this time hardware.... With the 1mb chipram expansion fitted, the machine boots fine from IDE, but the floppy stops recognising disks, and the RMB no longer functions. The memory is detected OK - I 'think' when I first fired up the machine before the recap that I ran a successful mem test using Amiga Test Kit, but am not 100%. Everything is fine without the expansion connected, but clearly memory is then super tight. (I've got an 8mb fast ram expansion on order). Any ideas on what signalling from the trapdoor interferes with the above? PS the trapdoor connector contacts are clean. Last edited by BennehBoy; 13 May 2021 at 13:46.

13 May 2021, 22:32	#38
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	Well something is very wrong. I have 3 Amiga PSU's here, all of which power my A500 just fine. With the ram expansion in the system vcc is 4.2V! Using an ATX supply it's 4.3V With the expansion removed it's 4.4V I measured VCC at the 555. Popping the SD2IDE & card out ups the voltage again to 4.5V Time to go study the power schematics.... I did remove/replace the line filter by the supply input to get more room to get at the caps, I don't think it got damaged, but if it had I'd expect full on failure rather than a supply drop... The ATX PSU is rated at 600W Last edited by BennehBoy; 14 May 2021 at 11:59.

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12 May 2021, 21:27	#21
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	I checked that in circuit and it was reading good, cheers

12 May 2021, 21:54	#23
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	Just rechecked it out of circuit and it seems to be OK.

13 May 2021, 12:27	#24
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	Seems pretty stable now that I thoroughly flushed the reset circuitry area. Next bits might need a new thread - shout if so. I've made a copy of my TF536 CF card onto a spare SD card which I've put into the a600 with an SD2IDE adapter. First hurdle was that it would hang at the wbload - pretty sure there were some 030 versions of files kicking about, so I used the 3.1.4 installer under winuae to refresh the install (I've also burnt and installed a 3.1.4 rom - all licensed btw). It now boots fine, but CLI won't run - I've checked all the library versions etc and they match. Any ideas?

13 May 2021, 12:36	#25
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	Never mind, found the problem, MUI.

13 May 2021, 18:56	#27
solarmon Registered User Join Date: Dec 2018 Location: UK Posts: 1,715	If you run a long memory test (over 100 rounds) on just the the expansion chip ram, does it pass or fail?

13 May 2021, 19:11	#28
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	I'll need to run it with diagrom - will feed back.

13 May 2021, 19:20	#29
solarmon Registered User Join Date: Dec 2018 Location: UK Posts: 1,715	Oh, I was confusing it with an A500 where you can boot with the expansion memory card disabled, then enable it for memory test. But you can't boot from IDE and run Amiga Test Kit from that?

13 May 2021, 19:29	#30
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	The floppy I have with Amiga Test Kit on is a bootable one that bypasses the OS and load binary... Is Amiga Test Kit launchable from WB? Honestly don't know - and I need to muck about getting it onto the HD if so. Will have a mess with it after the gym.

13 May 2021, 19:37	#31
solarmon Registered User Join Date: Dec 2018 Location: UK Posts: 1,715	Yes, in the Amiga Test Kit download zip file there is an ADF and a program file that can be run from Workbench. https://github.com/keirf/Amiga-Stuff/releases You just now need to figure out how to get it on the HDD/CF (i.e. mount it in WinUAE emulation, or use PCMCIA/CF transfer, or use serial transfer).

13 May 2021, 21:15	#32
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	Ah cool, I've been away from Amiga's since about 1994 so am having to relearn everything that I probably never knew in the first place Copied it on with WinUAE, it's sat running through the tests now, no issues so far, but right mouse & floppy not working with the ram in - quite bizarre.

13 May 2021, 21:43	#33
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	60 cycles and good so far

13 May 2021, 21:56	#34
solarmon Registered User Join Date: Dec 2018 Location: UK Posts: 1,715	Not sure if this was already mentioned to be good, but check the +5V rail and see if the power supply is OK.

13 May 2021, 22:14	#35
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	100 passes all OK, cancelled. Mouse checks show the RMB is stuck on: Floppy read test shows every sector bad This has to be a bad line or poor buffering, surely? I just don't know enough about what these signals _should_ look like. I've got a logic probe & DSO here if anyone has any thoughts about what to look at.

13 May 2021, 22:26	#37
solarmon Registered User Join Date: Dec 2018 Location: UK Posts: 1,715	I would check voltage rails getting to Paula, which the Right Mouse Button goes to, and also responsible for floppy data reads.

13 May 2021, 22:56	#39
solarmon Registered User Join Date: Dec 2018 Location: UK Posts: 1,715	Yeah, that is definitely not good. Just for testing, you can try powering the A600 through the floppy power port, to rule out anything with the normal power connector.

13 May 2021, 23:10	#40
BennehBoy Registered User Join Date: Apr 2021 Location: England Posts: 58	Even worse, 4.09V - And this is without the ram expansion or floppy connected. The ATX supply is putting out 5.11V without a load.

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