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Amiga 2000 - new to me

KC9UDX said:
In that configuration, just power supply and motherboard, does the power LED show any activity other than powering on?

That is, does it
1) turn on immediately on power up and always stay the same brightness
2) turn on immediately and after a short delay brighten
3) ever flash bright/dim, and if so after 1 or 2 above?

What version Kickstart ROM do you have?

What do you see on a composite monitor, if you can plug one in to the monochrome jack?

Do you get a raster? What colour is it? Does the colour ever change? (Brightness in stead of colour if monochrome.)
Click to expand...

To answer your questions:

The power LED lights as soon as the power supply is switched on. It glows at half-brightness for about two seconds and then full brightness thereafter. I attached a 1902A monitor in mono video mode and got the progression of shades of grey, ending with an "Insert Workbench 1.3" disk prompt.

I took the floppies (Chinon FB-354) apart and cleaned them. I took the power supply apart and cleaned it. Everything was very dusty but no visible signs of corrosion, except on the fan guard on the power supply.

What's the next test? (And by the way, thanks again for your guidance!)

-CH-

Pics:

A2000R6.2_39.jpg A2000R6.2_40.jpg
 
Looks good so far... plug in the floppy drive and see if it "click click clicks" with no disk in while powered up at the KS floppy image and then try to boot with a floppy disk (assuming you have one).
 
A turn for the worse:

I attached the floppy disk cable to the motherboard and to one of the floppies, as well as connecting it to the power supply.
The power supply lit up, the motherboard got to the "insert disk" display but no "tick" came from the attached drive.
I got a Workbench 1.3 disk and inserted it into the drive but got no reaction from the drive or motherboard.
Since I have two floppy drives I shut the machine down and switched drives.
Rather, tried to switch: The FD cable connector came apart in my hands as I was removing it from the floppy.
I spent an hour or more trying to repair the cable, destroying another in the attempt to get a working connector.
Unsuccessful, I returned to the broken cable and plugged it into the other drive anyway, and repeated the test.
This time on power up the motherboard did not boot, or make it past the dark screen.
I removed the drive and cable and repeated the test, with the same results.

I really don't know how to explain these results or where to turn next.

-CH-
 
If you have access to an EPROMmer, There's a debug ROM available that you can replace the KS rom with and do a number of different tests via the serial port. I'm thinking it'd probably be worth trying to reseat parts but if it comes to that, you should be able to burn the debug ROM and try that route.
 
Make sure your cabling is correct. It's very easy to get wrong. Make are both ends are keyed or that pin one matches the stripe.

Does your cable have a twist? It should, and that will cause correct drive numbering. But, if the cable doesn't have a twist (possible), then jumpers on the drivers will set the drive numbers. 0 will be DF0 and 1 will be DF1. You can jumper them for 2 and 3 but that will not work. Internal drives can only be 0 and 1.

If your cable has a twist, both drives have to be jumpered the same. I don't recall if they're both supposed to be 0 or 1. Also, I don't recall if the drive before or after the twist ends up being DF0.

Did the disk drive do anything at all on power up? I think if the motor doesn't briefly pulse immediately at power-on, that's an indication of a dead drive. Electronically dead, or maybe a stuck spindle.

Granted I could be wrong on any of that. I used to know it like the back of my hand but my memory just isn't what it yoosta shoulda been.

If the hard drive was working, the previous owner probably didn't use the floppy drives for years and they might be deader than dead.

If you unplug the drives and cable and can't get the insert disk prompt, you've got an intermittent problem, which could be any number of things.
 
It's worth noting too that the twist in a PC floppy cable is different from the Amiga if you attempt a substitution.
 
geoffm3 said:
It's worth noting too that the twist in a PC floppy cable is different from the Amiga if you attempt a substitution.
Click to expand...

Very true. Thanks for pointing that out. In the case of using one of those, the connector with the twist cannot be used,and then the drive jumper must be set correctly, 0, I think.
 
Thanks for your replies.

I did know a little about the drive cabling; I found it out in the past few days. Yes, I believe my cabling was correct. The cable (which is for two drives) had / has a twist in it, but the twist is pins 4-6, if I recall, and the PC twists 10-16. I was attempting to retrieve the connector off a PC cable, but the little clips that secure the top to the bottom of the crimp-connector kept breaking off. That was also the point of failure of the Amiga cable. I did not know about the straight-through option, though.

The end with the twist was keyed, as was the Chinon; only one way to insert that. The other end had a pin inserted in one of the sockets, and a space on the mobo connector, so it could not have been reversed either. Both drives were internally jumpered as df0.

There was no sound or movement from either of the drives upon Amiga startup. It bears repeating that I also tested with the drives completely detached, with the same (non)result.

I have two A500s and external drives for those. I was wondering if I might try the same test with one of those. I can't recall if the Amiga can boot from ANY floppy or only the internal. Prolly not, if the streak holds.

I still have to be able to get to the "Insert disk" prompt, so the point is moot for now.

-CH-
 
geoffm3 said:
If you have access to an EPROMmer, There's a debug ROM available that you can replace the KS rom with and do a number of different tests via the serial port. I'm thinking it'd probably be worth trying to reseat parts but if it comes to that, you should be able to burn the debug ROM and try that route.
Click to expand...

I'll try reseating first, then go to church, then try the EPROM method. I do have a Willem EPROM programmer that I got from the MCUMall a few years ago. I think it will handle the job* but I have to clear a few hurdles first:

The diagnostic ROM code to which you refer is published by "Chucky" at http://www.diagrom.com, I believe. If not, please direct me to the proper source.
The last offset in the 16-bit ROM code has address 0007FFF0, (18 00 19 00 1A 00 1B 00 1C 00 1D 00 1E 00 1F 00) which means that the KS ROM, which is reported to be 256k, will have to have a larger EPROM substituted having the same number (40) of pins. 27CWHAT?
Once I get that far I will need to figure out cabling and communication protocols for my remote terminal, which will need to have an RS-232 port.

Piece of cake.

But I'll give it a try; thanks for the suggestion.

-CH-

* Used to burn IBM 5160 Rev 3 ROMS and to program the XT-IDE with ChuckG's code. Thanks again to Modem7 and ChuckG for their help!
 
With the Kickstart ROM that you have, I'm pretty sure you can only boot from DF0, that is, not from any other floppy.

Unless someone can correct me, I'd say you have two dead drives. I don't recall any drive normally found in an Amiga that didn't pulse the motor on power up, and upon disk insertion, even with the data cable unplugged.

But yeah, you have other fish to fry.. :( also don't miss church for anything, specially this week if you're protestant. We have 500 years of earthly freedom to be thankful for.
 
Unseated each chip that was socketed; gave the pins a light sanding with #1500 sandpaper, reinserted them carefully... not even a blip on the raster now. One brightness on the LED; not sure if it's half or full, but not blinking.

It will take me a little while to decide what to do next. Thanks again to all for their suggestions.

-CH-
 
That's gotta be half brightness, meaning the Kickstart is either not running, or is crashing.

Maybe double check that you are still getting good power at the motherboard.
 
A very common failure of these when the battery leaks is for the 68000 to get so corroded by the leakage. To fix it you have to unsolder the socket and clean the area well, and install a new socket. Might also have to do the same to other nearby chips.
 
Update, as of 12/14/17:

Today the motherboard returned from its "vacation" in Finland. Shortly after my last post on this thread I found a post on AmiBay from "hese", aka Janne Heiskannen, who offered services for board repair.

After contacting him to describe my problem, discuss shipping, repair fees and time frame I mailed him the board, USPS Priority Mail. He received the board and repaired it and sent it back to me.

He told me that the reason for the non-start was that I had inserted the KS ROM backwards. However, he also made trace repairs, replaced the Denise chip which I had repaired with another I had also included with the board and replaced a couple of 74LSxx chips that were marginal. He also advised me that the Agnus socket was cracked; the board worked he said but the socket would be best if it were replaced. I authorized that repair also.

I haven't reassembled the A2000 HD but will be doing so soon. In the meantime here are a few pics of the board:

-CH-

RepairedBoard.jpg SocketRepair.jpg TraceRepair.jpg
 
clh333 said:
Update, as of 12/14/17:

Today the motherboard returned from its "vacation" in Finland. Shortly after my last post on this thread I found a post on AmiBay from "hese", aka Janne Heiskannen, who offered services for board repair.

After contacting him to describe my problem, discuss shipping, repair fees and time frame I mailed him the board, USPS Priority Mail. He received the board and repaired it and sent it back to me.

He told me that the reason for the non-start was that I had inserted the KS ROM backwards. However, he also made trace repairs, replaced the Denise chip which I had repaired with another I had also included with the board and replaced a couple of 74LSxx chips that were marginal. He also advised me that the Agnus socket was cracked; the board worked he said but the socket would be best if it were replaced. I authorized that repair also.

I haven't reassembled the A2000 HD but will be doing so soon. In the meantime here are a few pics of the board:

-CH-
Click to expand...
Wow, you sent your board to Finland for repair? I thought for further reference it might help to know there are people in the U.S. that repair Amigas.
This guy posts on the English Amiga Board forum. http://www.acill.com/ I believe he is in Southern California.
 
Assembled far enough to test; got power, got the screen progression and finally the workbench 1.3 prompt. This is as far as I have been able to progress. I have the two original floppies installed but the system does not recognize them. Possibly the fault of the cable, possible jumper issue - drive or motherboard, possibly just bad drives. I will try eliminating one FDD from the system. If that doesn't work I will substitute the FDD and cable from the other Amiga which has booted from a floppy already.

-CH-
 
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