Duo 230 - Resurrection

[pintodave]

So I pulled out the Duo 230 today to test it's operation, and it chimes, screen comes on, then the speaker starts squealing and it shuts down with the smell of burned electronics. This started happening around the time the hard drive would spin up.

I removed the logic board and connected everything seperately and it still starts, but no hard drive activity, it just won't spin up.

I washed/scrubed the board with vinegar, rinsed with water, and then with 91% IPA and dried it. Still nothing...

There is a rotted via on the back/bottom side of the board right beneath C36, an aluminum electrolytic, and C36 looks like it's time for replacement due to the leakage present prior to the board wash. The caps near the modem and power ports look fine, no signs of leaking, but that doesn't always mean they are not bad.

Is C36 for the hard drive's power circuit?

 

[pintodave]

Argh, posted in the wrong sub forum, can this be moved, please?

 

[Elfen]

Any pics?

By rotted VIA, you mean the connections to it are bad or the chip itself?

To me it sounds like something was shorted out, depending on the smell, either a cap or a chip. I'll assume its a cap.

I too am going through a similar case of Dying Duos. I managed to get one of them, a 250c going.

 

[pintodave]

There is a via centered beneath C36 which goes from the positive lead of C36 to either Pin 1 or 4 of VR4 on the other side of the board. There is also a via, center bottom, beneath C36 that is not connected to anything on top or bottom, but rotted.

 

[pintodave]

Turns out it's the scsi power circuit or something related. Put the same drive in another duo 230 i got off eBay for cheap and it works fine. Looks like it is now a parts unit. The eBay duo 230 is in much better shape, just swapped out the 4 mb ram card for my 14mb card and swapped the power switch board for the modem out of mine.

 

[Trash80toHP_Mini]

I'm glad to hear you got this sorted out to your satisfaction.

Duo devotees needs must assemble a goodly assortment of hangar queens. Be sure to hold onto that power board, there's no telling what may be bolted up to those in the future and they're relatively scarce little treasures. That's about the only cubic available in the Duo for wedging in something useful. A 14.4k Modem is pretty much useless ballast.

 

[wilykat]

A 14.4k Modem is pretty much useless ballast.

Useful for mods.  Take out the phone jack, solder in a 4 pin S-Video port and wire up 5v and ground from modem board plus ADB line from Duo's EXT connector and you have a built in ADB port. No need for a mini dock to use a different keyboard or mouse or use ADB peripheral.

I've done it. The hardest part is soldering the wire to the right pin of the Duo expansion connector.  Here's a still-working page that shows how to wire up ADB port: http://home.comcast.net/~gionpeters/hhhh/duo.htm

 

[Trash80toHP_Mini]

Yep, gotta love weird stuff, but that hack uses the Power Card I told the OP to hang onto. They're far more useful than the Modem today. I used to carry a PowerModem(?) for comms and only ever used the internal for faxing.

 

[Elfen]

Interesting.

What is the verdict on this Duo 230? It lives, it dies a slow death as a parts machine? it becomes a door stop?

 

[pintodave]

Parts unit unless I feel the modivation to dig into the logic board like my Portable and sort out the hard drive power issue. The case is all painted silver with blue accents and the screen has "rot" in the center from improper storage.

 

[Elfen]

I hope you can get something going with the Duo and put down your findings. Though I have not started on my Duo repairs, I would like some notes as to what you and others had done.

 

[pintodave]

The first step will be a recap, but I don't foresee it doing a whole lot, everything else starts up and works without issue, the hd just won't do anything. I'm thinking a rotted via or trace somewhere due to c36 spewing everywhere.

 

[Elfen]

That's usually the case. I have a Simasima SE/30, where looking through the magnifying glass, I have noticed a few traces have ben eaten by the goo in the upper left hand corner where there are 4 caps. Other areas have the solder joints corroded, so my work on that machine is cut out for me - recapping and trace rebuilding.

But similarly, with my Duo collection, many have leaked caps and I'm afraid to look at them but I have too though in time (probably after SE/30 and the Classic II).