Amiga 1200 capslock flashing, no boot.

Xtal · 28 July 2014, 14:52

I have a A1200 rev 2B which died unexpectedly (as always).

What's weird is that the keyboard capslock flashes all the time. I have several spares, and the PSU is ofcourse not the switched crap supply C= used for the 1200's. (The transformer based A500 PSU is a lot more reliable). It's a modified AT psu made by a well known maker (Seventeam) that's obviously a must for anything more than a bare "vanilla" A1200.

I need ideas. I know of the blinks of the keyboard controller, but I have never experienced a Miggy flashing it constantly. One reason might be that my trusty old 1960 multisync CRT experienced a high voltage arching inside, but nothing that would destroy any customchips, since it was the Flyby transformer that died of age. Now replaced and works flawlessly with my other A1200.

The A1200 was left on for about half an hour and I measured the temperatures of the SMD ICs and found nothing out of the ordinary (mostly ambient +2-3 celsius)

Floppy works, keyboard is OK, and the PCMCIA ethernet works fine, and the Phase 5 030@50MHz is just fine... And this is a Commodore produced 1200.

Ideas welcome.

DDNI · 28 July 2014, 16:31

This may help you. http://www.amigahistory.co.uk/selftest.html

One blink: Keyboard ROM check failed.
Two blinks: Keyboard RAM check failed.
Three blinks: Watch dog timer failure.
Four blinks: A short between two lines or the special control keys.

Xtal · 28 July 2014, 17:42

Nah, I know of the capslock codes, it's just this Amiga 1200 rev. 2b that flashes the capslock key constantly. I pulled all the gear inside and tried it into another A1200, and everything is okay. But something is obviously broken. And I'm stuck. So every idea is welcome. It flashes constantly and not in a "debug" way.

DDNI · 28 July 2014, 17:47

Did you try a different KB with the motherboard?

Toni Wilen · 28 July 2014, 17:59

Amiga is probably in reset loop and has nothing to do with keyboard. Does it still flash if all cables and expansions (display, mouse etc) are disconnected? Does it still flash if you remove one ROM chip? (Yes, weird question but it proves hardware problem if it keeps flashing)

Xtal · 28 July 2014, 19:41

Quote:

Originally Posted by Toni Wilen

Amiga is probably in reset loop and has nothing to do with keyboard. Does it still flash if all cables and expansions (display, mouse etc) are disconnected? Does it still flash if you remove one ROM chip? (Yes, weird question but it proves hardware problem if it keeps flashing)

Ehm, I'm actually blushing here since this was one of the first things I'd prone for oxidations/bad contacts. Shame on me!

No. Cleaning the ROM chips (it's a dual ROM Amiga) and the sockets with something not WD40 nor 5-56 didn't help.

I Still have the problem of a constantly flashing capslock LED and I can't make out if the picture from RGB is black or dark grey.

As said earlier, any idea is appreciated...

Xtal · 28 July 2014, 19:43

I could leave the Amiga on for hours and it still blinks the capslock repeatedlyg. Ofcorurse it blings when resetted (hardware or Ctrl-A-A) but I have never experienced a miggy flashing the capslock for hours. That's just weird.

Toni Wilen · 28 July 2014, 19:47

I meant do you get flashing led without nothing (except power) connected to the Amiga? One common problem is monitor that has too heavy load on sync signals (meant to be used with silver colored buffer box), this causes KS code to think there is genlock connected which will cause reboot loop. This is why it is important to test without anything connected.

Test 2: Power it on with all cables (except power) connected and also either (or both) rom chips removed, still led flashing?

Xtal · 28 July 2014, 20:02

Quote:

Originally Posted by Toni Wilen

I meant do you get flashing led without nothing (except power) connected to the Amiga? One common problem is monitor that has too heavy load on sync signals (meant to be used with silver colored buffer box), this causes KS code to think there is genlock connected which will cause reboot loop. This is why it is important to test without anything connected.

Test 2: Power it on with all cables (except power) connected and also either (or both) rom chips removed, still led flashing?

Thanks for the hints. I have a Philips 8833-2 "artist edition" (the one with some funku colour splashes, aswell as a CBM 8833 and so on.

What makes me wonder is why the keyboard LED flashes. It's not something I've seen before. Just plain weird.

Xtal · 28 July 2014, 22:17

Quote:

Originally Posted by Toni Wilen

I meant do you get flashing led without nothing (except power) connected to the Amiga? One common problem is monitor that has too heavy load on sync signals (meant to be used with silver colored buffer box), this causes KS code to think there is genlock connected which will cause reboot loop. This is why it is important to test without anything connected.

Test 2: Power it on with all cables (except power) connected and also either (or both) rom chips removed, still led flashing?

---
I've tried a custom powersupply with nothing but the bare 1200 and a FDD and keyboard. Very avare of the Genlock dilemma. Same itchy keyboard flashing. Keyboard is okay, and I can't find any conductive problems from the (well prune to erronuous behaviour) keyboard flatpack cable. (Custom powersupply is one of a ton of remodeled AT powersupplies).

Yes, the HSYNC and VSYNC (combined as CSYNC) needs a proper driver, since the amiga hardware can't produce enough Oompfh to a nice screen. So therefore the 23-15HD adapter supplied by CBM has a AND cmos device to fix that.

I'm stuck. I either have a busted keyboardcontroller ( Very unlikely ) or a Fried CIA. As I said earlier, every idea is welcome. No matter how bizarre. (Ues I'm capable of fitting a OCS DIL CIA to a surface mounted one.)

Everything ripped from the (until a week ago fully functioning) A1200 resides in other A1200 housing. Harddrive, Phase 5 68030/68882, and PCCARD ethernet.

So Every suggestion about what I've missed, even if its me not aligned to Mars and Jupiter ideas are welcome. And I can even custom paint your doormat with "a stupid swede was here" if you like that.

FOL · 28 July 2014, 22:42

Capacitor leakage over the reset IC. I have seen that cause this issue in the past.

Xtal · 29 July 2014, 06:56

Quote:

Originally Posted by FOL

Capacitor leakage over the reset IC. I have seen that cause this issue in the past.

Can you elaborate this further? This sounds weird enough for a try'n'fry

FOL · 29 July 2014, 10:26

Quote:

Originally Posted by Xtal

Can you elaborate this further? This sounds weird enough for a try'n'fry

Look for signs of capacitor leakage.

Xtal · 29 July 2014, 10:30

Quote:

Originally Posted by DDNI

Did you try a different KB with the motherboard?

Yes. I have a couple of A1200s from various revisions and the keyboard functions happily in another Rev 2b A1200. So Keyboard is okay. This is a fairly "unhacked" 1200 sp first thing was actually measuring the tracks on the flexcable, and they are within range of specs.

jbenam · 29 July 2014, 10:31

Quote:

Originally Posted by Xtal

Can you elaborate this further? This sounds weird enough for a try'n'fry

Look at this thread, it may be of help to you: http://eab.abime.net/showthread.php?p=958772

Can't remember if it also applies to A1200s though...

Toni Wilen · 29 July 2014, 10:49

All keyboard logic is on A1200 MB (most other models have keyboard microcontoller on keyboard itself).

This is the reason why I asked for testing without ROM chip, if led still flashes, it is near guaranteed to be problem with keyboard microcontroller or reset circuit.

Xtal · 29 July 2014, 21:34

I have had a lot of thunder here in a +30 celcius environment so I haven't been able to test things out as I should have. Seems though that the keyboard controller might have been fried. Will take me about a week to "recollect".

You guys (and gals) are beautiful when error checking "nostalgic" hardware.

Xtal · 01 August 2014, 18:14

Quote:

Originally Posted by Toni Wilen

All keyboard logic is on A1200 MB (most other models have keyboard microcontoller on keyboard itself).

This is the reason why I asked for testing without ROM chip, if led still flashes, it is near guaranteed to be problem with keyboard microcontroller or reset circuit.

Yes I know. I've as a service engineer used a couple of homemade A500 keyboard adapters for A1000, A2000 and A3000. I actually suspect the keyboard MCU has gone to the fried land. Reset circuitry is less prone to die from weird stuff. (But I have an open slot for that could be the reason of course)

Xtal · 05 August 2014, 21:16

Quote:

Originally Posted by jbenam

Look at this thread, it may be of help to you: http://eab.abime.net/showthread.php?p=958772

Can't remember if it also applies to A1200s though...

No only the A600 has the NE555 reset solution. I have to go through the schematics of the 1200 2B to find some clues.

FOL · 05 August 2014, 22:31

Quote:

Originally Posted by Xtal

No only the A600 has the NE555 reset solution. I have to go through the schematics of the 1200 2B to find some clues.

Cant remember off the top of my head, but the chips around the floppy area.

28 July 2014, 14:52	#1
Xtal Registered User Join Date: Jul 2014 Location: Mora, Sweden Posts: 36	Amiga 1200 capslock flashing, no boot. I have a A1200 rev 2B which died unexpectedly (as always). What's weird is that the keyboard capslock flashes all the time. I have several spares, and the PSU is ofcourse not the switched crap supply C= used for the 1200's. (The transformer based A500 PSU is a lot more reliable). It's a modified AT psu made by a well known maker (Seventeam) that's obviously a must for anything more than a bare "vanilla" A1200. I need ideas. I know of the blinks of the keyboard controller, but I have never experienced a Miggy flashing it constantly. One reason might be that my trusty old 1960 multisync CRT experienced a high voltage arching inside, but nothing that would destroy any customchips, since it was the Flyby transformer that died of age. Now replaced and works flawlessly with my other A1200. The A1200 was left on for about half an hour and I measured the temperatures of the SMD ICs and found nothing out of the ordinary (mostly ambient +2-3 celsius) Floppy works, keyboard is OK, and the PCMCIA ethernet works fine, and the Phase 5 030@50MHz is just fine... And this is a Commodore produced 1200. Ideas welcome.

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28 July 2014, 16:31	#2
DDNI Targ Explorer Join Date: Mar 2006 Location: Northern Ireland Posts: 5,432	This may help you. http://www.amigahistory.co.uk/selftest.html One blink: Keyboard ROM check failed. Two blinks: Keyboard RAM check failed. Three blinks: Watch dog timer failure. Four blinks: A short between two lines or the special control keys.

28 July 2014, 17:42	#3
Xtal Registered User Join Date: Jul 2014 Location: Mora, Sweden Posts: 36	Nah, I know of the capslock codes, it's just this Amiga 1200 rev. 2b that flashes the capslock key constantly. I pulled all the gear inside and tried it into another A1200, and everything is okay. But something is obviously broken. And I'm stuck. So every idea is welcome. It flashes constantly and not in a "debug" way.

28 July 2014, 17:47	#4
DDNI Targ Explorer Join Date: Mar 2006 Location: Northern Ireland Posts: 5,432	Did you try a different KB with the motherboard?

28 July 2014, 17:59	#5
Toni Wilen WinUAE developer Join Date: Aug 2001 Location: Hämeenlinna/Finland Age: 49 Posts: 26,519	Amiga is probably in reset loop and has nothing to do with keyboard. Does it still flash if all cables and expansions (display, mouse etc) are disconnected? Does it still flash if you remove one ROM chip? (Yes, weird question but it proves hardware problem if it keeps flashing)

28 July 2014, 19:43	#7
Xtal Registered User Join Date: Jul 2014 Location: Mora, Sweden Posts: 36	I could leave the Amiga on for hours and it still blinks the capslock repeatedlyg. Ofcorurse it blings when resetted (hardware or Ctrl-A-A) but I have never experienced a miggy flashing the capslock for hours. That's just weird.

28 July 2014, 19:47	#8
Toni Wilen WinUAE developer Join Date: Aug 2001 Location: Hämeenlinna/Finland Age: 49 Posts: 26,519	I meant do you get flashing led without nothing (except power) connected to the Amiga? One common problem is monitor that has too heavy load on sync signals (meant to be used with silver colored buffer box), this causes KS code to think there is genlock connected which will cause reboot loop. This is why it is important to test without anything connected. Test 2: Power it on with all cables (except power) connected and also either (or both) rom chips removed, still led flashing?

28 July 2014, 22:42	#11
FOL PSPUAE DEV Join Date: Nov 2006 Location: Wales / UK Age: 45 Posts: 6,012	Capacitor leakage over the reset IC. I have seen that cause this issue in the past.

29 July 2014, 10:49	#16
Toni Wilen WinUAE developer Join Date: Aug 2001 Location: Hämeenlinna/Finland Age: 49 Posts: 26,519	All keyboard logic is on A1200 MB (most other models have keyboard microcontoller on keyboard itself). This is the reason why I asked for testing without ROM chip, if led still flashes, it is near guaranteed to be problem with keyboard microcontroller or reset circuit.

29 July 2014, 21:34	#17
Xtal Registered User Join Date: Jul 2014 Location: Mora, Sweden Posts: 36	I have had a lot of thunder here in a +30 celcius environment so I haven't been able to test things out as I should have. Seems though that the keyboard controller might have been fried. Will take me about a week to "recollect". You guys (and gals) are beautiful when error checking "nostalgic" hardware.

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