exxos's Atari, Amiga & retro forum

Badwolf wrote: 26 May 2022 22:51

stephen_usher wrote: 26 May 2022 21:03 How big are real gobstoppers? I'm sure they'll grip if they get a bit sticky. ;-)

Buy a really big one and keep sucking till it fits!

BW

That's the ticket!!

Despite all the good stuff happening yesterday, I've got a horrible feeling that this is going to be a repeat of my Mega 4 thread. In other words, it's a long time before I get to the end!!

I started to look at the problems with the floppy last night and pulled the board so I could buzz things out. Sure enough I found a problem with one of the lines and ran a bodge wire to fix it. Just one bodge wire.

There was a temp battery in place, so I expected that CMOS would hold, put everything back in place powered on and.... back to FDD LED post codes.

What the...

So I disconnected one end of the bodge wire. No change. Hold down delete on boot to clear CMOS. Nope. I sometimes get a signal to the display, but nothing on screen.

I then noticed a small patch of corrosion on one of the SMD ICs, clean that up, nope. I now get this:


So I'm back to CMOS issues again. Dammit GRRRRRR.

Well, at least I am getting post codes, though after everything was running great yesterday bar the floppy, I'm kinda miffed.

I guess there is more to come on this one.

That's what I'm afraid of for mine.

Have you tested IDE yet?

I can see corrosion under my IDE connector socket, I don't want to but I think removing, cleaning, checking continuity and replacing the IDE socket might be necessary for me.

alexh wrote: 27 May 2022 10:56 That's what I'm afraid of for mine.

Have you tested IDE yet?

I can see corrosion under my IDE connector socket, I don't want to but I think removing, cleaning, checking continuity and replacing the IDE socket might be necessary for me.

I was trying to repair the FDD socket so I could run the formatting software for the HDD. FDD was working to the extent that I could read disks, but got an error 23 when formatting or running hform from the floppy disk.

I have similar concerns re the IDE socket, but I can only work on one thing at a time, and now that means getting the board to boot again. I'm concerned that something much more serious has failed, in particular something major, though why after installing one bodge wire I'm unsure.

Of course it could be more connections have failed mechanically when I handled the board as it is old and areas near the battery may still be fragile.

rubber_jonnie wrote: 27 May 2022 10:26 There was a temp battery in place, so I expected that CMOS would hold, put everything back in place powered on and.... back to FDD LED post codes.

What's your battery voltage? Is it's possible it's discharged (often through the motherboard if diodes aren't quite in the right spot) taking you back to square one?

BW

Badwolf wrote: 27 May 2022 12:04

rubber_jonnie wrote: 27 May 2022 10:26 There was a temp battery in place, so I expected that CMOS would hold, put everything back in place powered on and.... back to FDD LED post codes.

What's your battery voltage? Is it's possible it's discharged (often through the motherboard if diodes aren't quite in the right spot) taking you back to square one?

BW

Voltage is just under 3.3v, so well within the operating voltages of the RTC/CMOS IC. Even if the battery is dead, pressing delete on boot should set defaults, it's not even doing that anymore, so something new has failed, I'm sure of it.

Also, I'm looking at some other areas of the board and I think some of the caps have leaked, so I need to look at replacing those and checking for trace failures.

I love a good project....

rubber_jonnie wrote: 27 May 2022 13:17 I love a good project....

I'm dreading getting my A3000 out again. I bet I didn't get everything first time around...

BW

Badwolf wrote: 27 May 2022 13:23

rubber_jonnie wrote: 27 May 2022 13:17 I love a good project....

I'm dreading getting my A3000 out again. I bet I didn't get everything first time around...

BW

I'd do it sooner rather than later...

Well, it's been a good afternoon with the A5000, especially after it died on me after the initial repair à-la Mega STE!!

I had been advised that caps are not usually a problem, but there are 5 around the RAM/ROM area that are the little aluminium dustbin type:


I hate those little buggers, just one nearly destroyed my Amstrad Alt-386, and the ones in my A1200 were caught, but barely in time!!

Looking closer there was a distinct area around each one that was showing signs of leakage, with nearby components grimy and black, a good indicator that cap goo is flowing.


So I removed them, and sure enough, once I got desoldering there was a distinct fishy odour, so my suspicions were correct.

Out of the 5 caps, 4 came off cleanly, but one came away complete with one of the pads, another sign that leaky capacitors were using their goo to eat away crucial parts of the board.

Once removed I gave everywhere a good cleanup.

I used my previous technique of a flattened piece of tinned wire to a nearby via to complete the repair:


Whilst it isn't a nice rectangular shape, it is at least a workable solution.

With repairs done, and a default set of the CMOS, it's running again :)


Which is a bit of a relief.

So back where I started around Wednesday, but I'll take the win for now. Next up it's fixing the FDD as it's still giving me a 23 error (I have the recommended parts on the way) and I'll need the FDD to work in order to run the IDE formatting tool, though at the moment due to it dying on me, I haven't even buzzed out the IDE lines!!

Lucky that fixed it. (Or experience?) Anyhow nice read. Good to see you're going again