Screen flicker on floppy access

gazj82 · 10 April 2016, 12:22

I noticed my A1200 has a slight flicker on screen every time the Floppy drive does it's check for disk. This is only very slight, not sure if it has always done it and it has only taken me 20 years to notice. Trouble is now I know it drives me crazy.

Anyway my Motherboard is a rev 1D.4 and this webpage points out a fix using a capacitor soldered across location D215A the problem is my motherboard already has a resistor at this position!

Anyone have any idea why this might be here, was it a fix done by someone else? I got my A1200 in about 1998 so it is possible someone else put this in before I owned it.

Final question, should I be taking this out and putting in the recommended capacitor? or do you guys think this might be my Amiga telling me it is due for a all round capacitor change.

Thanks guys
GazJ

turrican9 · 10 April 2016, 13:02

Quote:

Originally Posted by gazj82

I noticed my A1200 has a slight flicker on screen every time the Floppy drive does it's check for disk. This is only very slight, not sure if it has always done it and it has only taken me 20 years to notice. Trouble is now I know it drives me crazy.

Anyway my Motherboard is a rev 1D.4 and this webpage points out a fix using a capacitor soldered across location D215A the problem is my motherboard already has a resistor at this position!

Anyone have any idea why this might be here, was it a fix done by someone else? I got my A1200 in about 1998 so it is possible someone else put this in before I owned it.

Final question, should I be taking this out and putting in the recommended capacitor? or do you guys think this might be my Amiga telling me it is due for a all round capacitor change.

Thanks guys
GazJ

I have this on all my Amiga 500s. Haven't tested it on my 1200 and 600 because I only use those for whdload. As far as I understand this is perfectly normal.

gazj82 · 10 April 2016, 13:08

I usually use WHDLoad these days so probably wouldn't usually notice it as the floppy disk get's disabled as you say.

It was only playing nethack in workbench with the disk click going that I noticed yesterday.

I guess I wouldn't have noticed it years ago using an RF modulator either.

gazj82 · 10 April 2016, 23:35

Well, i took out the resistor and put a capacitor in, but unfortunately it didn't make a difference. I also get a small bit of interference when using the keyboard at times.

It could just be me being fussy as when I pointed it out to my wife it took her about 5 minutes to notice it.

patrik · 11 April 2016, 00:19

Also have this on my A500+ and A2000. Have not had any of these computers since new, so I unfortunately have no idea if this is how they are supposed to be or if it is a result of aging capacitors.

However I can recommend enabling noclick, then you will only see the flicker when actually using the drive.

gazj82 · 11 April 2016, 01:14

I really should enable it, the drive doesn't even do it once in use. It is just when it starts the drive motor from a standstill that it occurs.

10 April 2016, 12:22	#1
gazj82 Registered User Join Date: Jan 2014 Location: Cambs / UK Posts: 356	Screen flicker on floppy access I noticed my A1200 has a slight flicker on screen every time the Floppy drive does it's check for disk. This is only very slight, not sure if it has always done it and it has only taken me 20 years to notice. Trouble is now I know it drives me crazy. Anyway my Motherboard is a rev 1D.4 and this webpage points out a fix using a capacitor soldered across location D215A the problem is my motherboard already has a resistor at this position! Anyone have any idea why this might be here, was it a fix done by someone else? I got my A1200 in about 1998 so it is possible someone else put this in before I owned it. Final question, should I be taking this out and putting in the recommended capacitor? or do you guys think this might be my Amiga telling me it is due for a all round capacitor change. Thanks guys GazJ

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10 April 2016, 13:08	#3
gazj82 Registered User Join Date: Jan 2014 Location: Cambs / UK Posts: 356	I usually use WHDLoad these days so probably wouldn't usually notice it as the floppy disk get's disabled as you say. It was only playing nethack in workbench with the disk click going that I noticed yesterday. I guess I wouldn't have noticed it years ago using an RF modulator either.

10 April 2016, 23:35	#4
gazj82 Registered User Join Date: Jan 2014 Location: Cambs / UK Posts: 356	Well, i took out the resistor and put a capacitor in, but unfortunately it didn't make a difference. I also get a small bit of interference when using the keyboard at times. It could just be me being fussy as when I pointed it out to my wife it took her about 5 minutes to notice it.

11 April 2016, 00:19	#5
patrik Registered User Join Date: Jan 2005 Location: Umeå Age: 43 Posts: 925	Also have this on my A500+ and A2000. Have not had any of these computers since new, so I unfortunately have no idea if this is how they are supposed to be or if it is a result of aging capacitors. However I can recommend enabling noclick, then you will only see the flicker when actually using the drive.

11 April 2016, 01:14	#6
gazj82 Registered User Join Date: Jan 2014 Location: Cambs / UK Posts: 356	I really should enable it, the drive doesn't even do it once in use. It is just when it starts the drive motor from a standstill that it occurs.

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