[Amiga] A2000 Battery Recovery

This is another repeated article from www.amiga.org.

Hi people,

in case someone needs to repair some damage done to the Amiga 2000 mainboard by a leaking battery, this is the right place for you.
Found that A2000 on eBay a few days ago. It was sold as defective and would not power up. Obviously, the seller didn't know too much about the computer, but I took the risk and got the item for about 45 EUR. Not too much loss if it was irrepairably broken.
It's a fascinating machine, pretty large and with a lot of space inside, so I won't ever need to think about heat dissipation like in my two A3000 models. In comparison, they are pretty crowded and less maintainable. The A2000 features the largest PCB of all Amigas (it's actually huge, about 4 times an ATX mainboard), and except for Agnus who is PLCC, all custom chips are still DIP-shaped like in the Amiga 500. A lot of Zorro slots provide great extensibility, and I was happy to find a Kickstart 2.0 ROM in there. Not much more though, no RAM expansion, no hard disk drive or anything else.
I have made an attempt to repair it today as this was another battery leakage victim like most of the Amigas who boast an RTC. The battery has done some bad-looking corrosion to the mainboard, and as the CPU socket is quite near to the battery, it was affected, too.

Tools needed to do this repair:

• soldering iron (mine is an Ersa Multitip 15 Watts, about 25 years old)
• some solder wire
• unsoldering tool (I used a cheap one-shot-and-reload vacuum pump with a silicon tip)
• multimeter to check that the PCB connections are still okay
• in my case, a new 68000 socket (DIP-64)
• (later) a button battery (CR2025 or CR2032) and an appropriate clip
• (later) a diode for the new battery to prevent destructive recharging attempts by the board

And here's what I did:

• completely disassembled the A2000 to find a 5,25" drive inside that does not connect to the board directly. Obviously some freak has converted a former external drive into an internal one, also keeping the adaptor PCB and a lot of cable straps, sigh... the connector cable needs to go out of the case to the external floppy port... ah well, that's going to be a different thread. I don't think I can bear this for long :-D
• removed the mainboard from the case and cleaned it a little. Some big flakes of dust have accumulated there over the years
• removed the battery (sorry, no pictures here) and thoroughly cleaned the PCB in that area. I noticed that the PCB is pretty delicate when trying to unsolder. The solder mask becomes damaged when exposed to too much heat for too long (and in this case, I think it is lots shorter than usual), and probably one would easily kill leads unless being extremely careful. Maybe the board's age adds to it.
• checked damage done by the corrosion. Nothing seemed to be actually broken and no leads seemed disrupted by the corrosive process. I sure hope it does not continue in the future.

The old battery after removing. I can't understand how Commodore could be so stupid as to place batteries directly on the board with no socket. Sigh... well, that seems what everybody did those days.

Notice the dark spots left by the corrosive. It has come pretty far and even dug along under the battery lead. The CPU socket shows traces of corrosion, too. See the greenish pins 1 to 6. I think this is the main reason the A2000 has failed (probably no good contact anymore)

Different angle

• I decided it's hopeless to clean the socket, plus I wouldn't get a chance to see if anything is broken beneath the socket, so I removed it completely. As unsoldering this item without damaging the board is near impossible, I broke the socket frame and pulled the plastic parts of it away from the board, leaving only the metal pins.

68000 socket, no plastic frame

• then I unsoldered all the pins one by one while pulling them away with a pair of pliers on the other side. That worked pretty well but left the soldering eyelets closed in most cases.

Socket debris

• to make unsoldering easier, I put some solder on all the eyelets so they would heat up more quickly on both PCB sides

68000 socket eyelets prepared for de-soldering

• after unsoldering, a visual check of the board against outside daylight offered no obstructed eyelets:

Shiny!

• this was a good time to do some measuring on the leads in the area affected. As it seems, all are fine, no leads broken. I scratched the masking paint from the place where the battery cathode was placed to see what has happened there. See the bluish touch of that beastly stuff?

Socket gone - blue traces of battery sludge beneath the masking paint

• now I inserted the new 64-pin socket and fixed it

New 68000 home from the PCB bottom

68000 replacement socket top view

Mind the copper lead I found where the battery was. Obviously there was no actual damage although the lead may have been thinned out considerably.

68000 in place again

68000 edge view

After connecting to the PSU and floppy, I carefully started the machine for the first time since I received it. The Kickstart screen came up and first attempts to load disks were successful! Yippieee, day saved! :-)

There are some things to do though. As I don't have a button battery and socket handy, I will have to do that replacement later. Maybe I'll post some photos about that, too.

Hope you liked this A2000 revival story!

Have a nice day,

Joe

[Amiga] Scandy A1200 Flicker Fixer

Hi people,



I've posted this article at amiga.org before, but as I want to keep track of all my projects here, I think it's okay to repeat.

Full view

The main PCB installed

Some time ago I got hold of a Scandy A1200 scan doubler module for the Amiga 1200. It consists of three PCBs which are plugged on top of LISA and both CIA chips inside the A1200. It features an additional VGA port, output is the same as on the video port, so you can use two monitors at the same time.
After some hours in vain trying to find a documentation about how to install it, I have decided to try on my own and let you folks know. I'd either find a way how to destroy the A1200, or successfully get the Scandy working. Luckily, the latter happened ;o)

In fact, cable lengths and positioning make it hard to mount the Scandy in more than one (correct) way, nevertheless I had felt better if there had been a paper instructing me.

After mounting it looks something like this:



Micronik has tried to indicate the orientation of the PCBs by putting the 45-degree edge of the socket in the same place it is on the respective chip, at least for LISA and the U7 CIA. The edge of the U8 does not point to the right direction though but never mind, as the pin count is the same on all edges it fits anyway.

The CIA sockets indicate where they belong so you can't do it wrong (see print beneath each socket):

U7 CIA (below parallel port)

U8 CIA (right above floppy connector)

Closeup of U7 and U8

All add-on PCBs

After some plugging and unplugging it finally worked. Maybe one should first check the socket pins for corrosion and dust which I forgot. My first results were "no VGA signal", and later the signal was first okay but seemed to collapse within a few seconds, with the CRT finally going to standby mode. No idea where that came from, eventually it seems to be okay.
Now I'll have to think about how to move the hard disk drive to another location as the Scandy becomes pretty warm over time. So please be warned: you should *not* put anything directly on top of the Scandy main PCB, it definitely needs some room to get rid of that heat!

The following photos were taken from a Dell WFP2407 TFT.

SysInfo

IntuiTest (640x512 @ 256 colours)

The IntuiTest screenshot indicates that there is no "flicker fixer" function. Scandy does not buffer complete frames but, to put it simple, buffers only the line that is currently sent to the CRT or TFT, and sends each pixel twice (i.e. with double speed) to the screen attached to the VGA port which in effect doubles the horizontal frequency without presenting a different content. I didn't expect anything else because a real flicker fixer is usually way more complex. This also explains why a Scandy A1200 only costs about half as much as, say, an Indivision 1200.
If you plan to use your A1200 mainly for gaming and less frequently for working (especially in interlace modes), the Scandy A1200 is a clever solution.
Just consider that most of the CompactFlash adapters will collide with the Scandy main PCB, as does my hard disk right now (missing the original metal shielding *argh*)

I hope this is helpful for some of you ;-)

Greets,
Joe

Mushkin 240GB SSD Drive for the W510

Hi everybody,

time for another first: my first notebook without mechanical drives!
The Lenovo W510 was delivered with an 160GB Intel Postville SSD drive built-in for the Windows Server 2008 system and program files, and a second 500GB Seagate Momentus 7200.4 SATA hard disk in the UltraBay (where usually a DVD or BD drive is installed). The Intel SSD got me pretty excited already as it's the first time I have ever seen Windows Server 2008 boot up in less than a minute from powering on until the desktop is ready to use. No more need for hibernation, yippieeh!
My idea was to use the larger disk for hosting VirtualBox hard drive images which I need for working on different platforms, and thus its performance was kind of vital.
As I'll soon work with a Microsoft Office Project Server 2010 Hyper-V development system soon that contains Windows Server 2008, SharePoint 2010, and Microsoft Visual Studio 2010, I believe you cannot have enough performance, this monstrum will still bring any system to its knees.
The Momentus disk is fast but I just wanted to find out if an SSD could go beyond that.
Well, it's gone impressively beyond the speed index I knew so far!

Package

Unlike earlier Mushkin metal case packages, the one I got is rather simple:

The package reveals a kind of "book" filled up with solid rubber foam to keep the valuable SSD safe.

Some screws (8 pieces), that's it. Not even a manual, a cable or anything. I'm a little disappointed that no 5,25-inch mounting frame was delivered. It seems there is some space reserved in the box to keep one. Well, I won't need it anyway now.

Okay, here's the protagonist:

Sorry, no "inside" pictures as I want to keep the warranty intact. If you want to see the innards though, look here, it's a review of the 60GB version: Legit Reviews - Mushkin Callisto 60GB.
The SSD replaces the Seagate Momentus disk in the UltraBay frame:

Ready to go. Here are some first test results. Please note that I used the notebook during the test, and the partition on which the test(s) ran were everything but empty. That drops results considerably I think. What counts for me is that the perceived speed is much higher now, especially when working with my VirtualBox machines.

Iometer 2006.07.27 results (1 Worker active, results after approx. 2 minutes)

More speed measurements by DiskTT:

DiskTT with 4kB block size - expectedly bad results

DiskTT with 64kB block size - now we're getting somewhere!

DiskTT on ecstasy! Excellent performance at 512kB block size

Iometer is a rather old tool, and reported the "worst" results. Well, I'm not too familiar with the program. A constant transfer of nearly 80MB/sec (reading and writing) is not too bad for a start. Well, there values are of course rather theoretical ones, and I have caused some impact by using the machine a little during the tests. Nonetheless, all this is way better than the previous classic hard disk.
Now let's hope it stays that way. There is a lot to read about performance dropping once the SSD needs to overwrite blocks that are not empty. Windows 2008 is TRIM-enabled and will hopefully keep the performance up. If there will be problems, there will be a blog :)