A600 screen scan weirdness

Amiga1992 · 21 March 2010, 07:32

I have noticed my A600 does a weird flicker/scan when the hard drive is not being read or written to. Does anybody have a clue why this might happen? When teh drive is accessed, this flicker/hum disappears, until the bus is idle again

rkauer · 21 March 2010, 21:22

Weak power supply or, more likely, bad capacitors.

Philophus · 21 March 2010, 21:34

When the hard drive is NOT In use?...wouldn't indicate weak power supply unless it was the other way around.

Loedown · 21 March 2010, 21:38

Quote:

Originally Posted by Philophus

When the hard drive is NOT In use?...wouldn't indicate weak power supply unless it was the other way around.

The hard drive might actually be loading down one of the lines a bit, in its own way acting as a filter.

I'd vote caps.

DDNI · 21 March 2010, 21:51

do you have anything connected to PCMCIA?
What video output are you using?

Philophus · 22 March 2010, 00:04

Quote:

Originally Posted by DDNI

do you have anything connected to PCMCIA?
What video output are you using?

Good thinking...i bet it's an SRAM card causing it.

PowerPie5000 · 23 March 2010, 01:47

Quote:

Originally Posted by Philophus

Good thinking...i bet it's an SRAM card causing it.

I've never experienced a problem like that when using SRAM cards with an A600 (rev 1.5 and 2D) and A1200 (rev 1D1 and 1D4)

rkauer · 23 March 2010, 02:32

I can bet with confidence the problem you are experiencing is caused by bad capacitors.

Swap the buggers and the Amiga will gain a new life.

PowerPie5000 · 23 March 2010, 03:21

Quote:

Originally Posted by rkauer

I can bet with confidence the problem you are experiencing is caused by bad capacitors.

Swap the buggers and the Amiga will gain a new life.

I'm pretty sure Akira mentioned somewhere that all the caps had been newly replaced on his A600 motherboard... can't remeber where that post or thread is

Anyway, if the caps are the problem then i would take the A600 back to whoever repaired it

Dagger · 24 March 2010, 04:46

I have the same problem with mine. I don't think its the caps as the screen flickers on my 1200 and 600 on hd(CF CARD) access with my sram card inserted. Surely both machines cannot be faulty.

rkauer · 24 March 2010, 08:01

Yes, they can.

Those capacitors from 1990~1993 are pure crap and start to leak after just a few years.

PowerPie5000 · 25 March 2010, 03:35

Quote:

Originally Posted by rkauer

Yes, they can.

Those capacitors from 1990~1993 are pure crap and start to leak after just a few years.

It would be interesting to see how many people have actually had capacitor issues with their Amiga's. I've easily owned 10 or more Amiga systems over the years and have never experienced any capacitor issues at all! (4 x A600's, 3 x A500's, 3 x A1200's as far as i remember but could be more

).

I must be lucky

Philophus · 25 March 2010, 12:39

Never had a problem with them myself in many years of Amiga-ing.

Now batteries.... different scenario altogether....damn things!

Dagger · 27 March 2010, 04:50

I would have never known until it was to late that I had bad caps if I had'nt purchased that Sram card. I have since bought another 600 and that has no flicker at all on start up with the sram card inserted. Looks like I will have to off load my other 600 and 1200 now as changing caps is a bit over the top for me.

Loedown · 27 March 2010, 10:23

Quote:

Originally Posted by Dagger

I would have never known until it was to late that I had bad caps if I had'nt purchased that Sram card. I have since bought another 600 and that has no flicker at all on start up with the sram card inserted. Looks like I will have to off load my other 600 and 1200 now as changing caps is a bit over the top for me.

There's a multitude of users here who can change your caps, I don't know where you live so I cannot suggest someone.

Amiga1992 · 28 March 2010, 05:47

Quote:

Originally Posted by rkauer

I can bet with confidence the problem you are experiencing is caused by bad capacitors.

I just got them ALL changed except two (located on the right side of the motherboard, looking at it from the front).
The repair shithead, who took two months to do this, said those two were "OK"
Anwyay, I'd bet some of these caps might be of teh wrong denomination? How can I tell?

HALP!

rkauer · 28 March 2010, 06:43

Akira, my friend: grab a solder iron and replace all of 'em, no matter what the guy did.

Using a pair of pliers, fresh/spanking new capacitors and good solder will make wonders to your battered A600.

Remember: if you want a good job, do it yourself!

BTW: if our countries real do a "Mercosul" job I can make the job in a week. Too bad customs and postal services are golden crap for us.

Amiga1992 · 28 March 2010, 16:15

I would never do this, I'm REAL BAD with soldering. I mean it.
I'll try to see if someone else can change what has been left unchanged, however, if the caps have been replaced mistakenly, how am I to know? Is there a list of "this cap goes here" sort of? That way I can recognize if something has been replaced wrong.

rkauer · 29 March 2010, 03:32

Just read the A600 schematics: in the first pages lies the capacitors list, named by value and where they go.

Amiga1992 · 30 March 2010, 05:18

Uhm, I'd need a link to such file :P
Obrigado

I noticed the screen also has some oddness on colours. These fuckers definitely put the wrong caps. now I need to fix this...grrrrrrrrrrr.

21 March 2010, 07:32	#1
Amiga1992 Registered User Join Date: May 2001 Location: ? Posts: 19,645	A600 screen scan weirdness I have noticed my A600 does a weird flicker/scan when the hard drive is not being read or written to. Does anybody have a clue why this might happen? When teh drive is accessed, this flicker/hum disappears, until the bus is idle again

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21 March 2010, 21:22	#2
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	Weak power supply or, more likely, bad capacitors.

21 March 2010, 21:34	#3
Philophus Registered User Join Date: Mar 2010 Location: Hampshire Posts: 151	When the hard drive is NOT In use?...wouldn't indicate weak power supply unless it was the other way around.

21 March 2010, 21:51	#5
DDNI Targ Explorer Join Date: Mar 2006 Location: Northern Ireland Posts: 5,431	do you have anything connected to PCMCIA? What video output are you using?

23 March 2010, 02:32	#8
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	I can bet with confidence the problem you are experiencing is caused by bad capacitors. Swap the buggers and the Amiga will gain a new life.

24 March 2010, 04:46	#10
Dagger Registered User Join Date: Aug 2009 Location: Dagenham / England Posts: 182	I have the same problem with mine. I don't think its the caps as the screen flickers on my 1200 and 600 on hd(CF CARD) access with my sram card inserted. Surely both machines cannot be faulty.

24 March 2010, 08:01	#11
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	Yes, they can. Those capacitors from 1990~1993 are pure crap and start to leak after just a few years.

25 March 2010, 12:39	#13
Philophus Registered User Join Date: Mar 2010 Location: Hampshire Posts: 151	Never had a problem with them myself in many years of Amiga-ing. Now batteries.... different scenario altogether....damn things!

27 March 2010, 04:50	#14
Dagger Registered User Join Date: Aug 2009 Location: Dagenham / England Posts: 182	I would have never known until it was to late that I had bad caps if I had'nt purchased that Sram card. I have since bought another 600 and that has no flicker at all on start up with the sram card inserted. Looks like I will have to off load my other 600 and 1200 now as changing caps is a bit over the top for me.

28 March 2010, 06:43	#17
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	Akira, my friend: grab a solder iron and replace all of 'em, no matter what the guy did. Using a pair of pliers, fresh/spanking new capacitors and good solder will make wonders to your battered A600. Remember: if you want a good job, do it yourself! BTW: if our countries real do a "Mercosul" job I can make the job in a week. Too bad customs and postal services are golden crap for us.

28 March 2010, 16:15	#18
Amiga1992 Registered User Join Date: May 2001 Location: ? Posts: 19,645	I would never do this, I'm REAL BAD with soldering. I mean it. I'll try to see if someone else can change what has been left unchanged, however, if the caps have been replaced mistakenly, how am I to know? Is there a list of "this cap goes here" sort of? That way I can recognize if something has been replaced wrong.

29 March 2010, 03:32	#19
rkauer I hate potatos and shirts Join Date: Oct 2007 Location: Sao Leopoldo / Brazil Age: 58 Posts: 3,482	Just read the A600 schematics: in the first pages lies the capacitors list, named by value and where they go.

30 March 2010, 05:18	#20
Amiga1992 Registered User Join Date: May 2001 Location: ? Posts: 19,645	Uhm, I'd need a link to such file :P Obrigado I noticed the screen also has some oddness on colours. These fuckers definitely put the wrong caps. now I need to fix this...grrrrrrrrrrr.

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