Powerbook Duo 2300c - power on chimes but nothing else...

[Sideburn]

Hey all,

I just acquired a PB Duo 2300c in trade to build some battery packs for that model but all it does at power up is make a startup chime.
There's no hard drive sounds and the display never lights up.

Does anyone know if this is common and if there are some troubleshooting and repair tips?
I found online that the logic board has at least one metal can surface mount cap but I think in total there's only about 5 caps:

4x 100uf 35v
1x 100uf 25v
1x 47uf 35v
1x 33uf 25v - this one is the metal can (prone to leakage)

Also the keyboard is very stiff and mushy. I think this is common because i have run across some vids with others doing the same. they barely return to their original position. Is there a known way to clean and fix this?

I'd like to repair this one if possible since it's in pristine cosmetic condition otherwise.

I also need a working machine to test the battery pack rebuilds.

Thanks for any help,

-Tavis

 

[Powerbook27364]

Logic board needs to be recapped. All 5 are electrolytic surface mount can style. I'm not entirely sure, but there may be capacitors on the display as well. Hard drive not spinning may be a dead drive or there may be a deeper problem. Is there any corrosion on the battery or in the computer?

Keyboards on all of mine were stiff initially, but after some cleaning and some usage, they seem to get better. My duo 280 had a very bad keyboard but after some use and cleaning it all up, it is not bad now, also pristine condition.

I also have a 2300c logic board in questionable condition (no chime and a green power led stays solid), so let me know how your repairs go. Good luck rebuilding the batteries. They are a very tight fit!

 

[Sideburn]

Oh ok I thought there were tantalum caps on it. I haven't opened it up yet. The batteries look fine. No corrosion.
I will know more once I open it up. I guess there's no way to rule out the display as the problem by connecting an external display without a dock.
Yeah this pack rebuild looks like a challenge... Multiple voltages too. Also making an attempt at rebuilding Pismo/Lobard packs.

 

[Powerbook27364]

All are electrolytic, but some can be replaced by tantalums. Sometimes having the battery in will prevent booting.
When you open it, reseat all the connectors and cables to rule a loose connector out. If the backlight is dead, but the display works, it will still look like the display is off, so you can use a flashlight up against the display to give some light and see if anything is displayed. Docks are unfortunately uncommon and expensive.

The pack requires 10x 4/5a Ni-MH cells and a spot welder in order to fit. I may have some photos or a layout diagram of my rebuild somewhere and I'll send here if I can find.

 

[Sideburn]

All are electrolytic, but some can be replaced by tantalums. Sometimes having the battery in will prevent booting.
When you open it, reseat all the connectors and cables to rule a loose connector out. If the backlight is dead, but the display works, it will still look like the display is off, so you can use a flashlight up against the display to give some light and see if anything is displayed. Docks are unfortunately uncommon and expensive.

The pack requires 10x 4/5a Ni-MH cells and a spot welder in order to fit. I may have some photos or a layout diagram of my rebuild somewhere and I'll send here if I can find.

OK, Yeah I have made a few packs now.. I have a spot welder. Ive recapped and repaired several boards, just not familiar with the duos...
Going to try that flashlight trick now.

 

[Sideburn]

It lives! I opened it up and removed the ram and all the connectors and then reseated it all and powered on and had a screen and no hard drive then I tapped it and it fired back up! Lol easiest fix ever.

On the packs.when I had the machine apart I measured

With “-“ lead on far right copper tap I get

[+20v][+5][+0][gnd]

 

[Powerbook27364]

Haha nice fix! Was it by chance a Connor drive? They are known to have sticky bumpers inside the drive. I don't have my duos in this country, so I have no idea what those leads are supposed to measure.

 

[Sideburn]

Haha nice fix! Was it by chance a Connor drive? They are known to have sticky bumpers inside the drive. I don't have my duos in this country, so I have no idea what those leads are supposed to measure.

Uhg I just put it all back together and forgot to look or take photos.

Now to make this thing complete I need a batter back with the sliding cover and the back left tilting tab that covers the modem is broken.

And the keyboard is stiff as hell. Someone needs to make a new repro rubber membrane for these.

And I guess there’s no way to put a BlueSCSI WiFi in it since it’s IDE. WiFi would be sweet sonce there’s no ports on back without a dock your kinda screwed.

Other than that it’s on pretty good shape!

 

[Powerbook27364]

Actually, I believe the 2300c has a connector for SCSI and you just need the cable. It looks absolutely fantastic!

Keyboards on the duo lineup were generally bad, even when new so not a whole lot can be done. I wonder how much a rubber membrane would cost to produce...

 

[Sideburn]

Actually, I believe the 2300c has a connector for SCSI and you just need the cable. It looks absolutely fantastic!

Keyboards on the duo lineup were generally bad, even when new so not a whole lot can be done. I wonder how much a rubber membrane would cost to produce...

Oh I think I’ve seen that it’s a dock connector that has two ports and one is the square scsi connector. Is that what you mean?

Actually now you got me thinking you could probably make a mold of it and re-cast it in a a soft silicone.

 

[Powerbook27364]

No, I mean that on the logic board internally, the 2300 has connectors for both SCSI and IDE hard drives, as well as all duo displays. The board was offered as an upgrade for all existing duos to PowerPC and thus is compatible with both IDE and SCSI as well as both the older passive matrix displays and the newer color active matrix displays.

 

[Sideburn]

Ohhh wow ok. So I wonder if you can put a bluescsi in one then.

The drive was silver so I think it was a quantom and not a Conner.

 

[LaPorta]

Did any of you guys happen to note the model number of the display? I need a new one.

 

[3lectr1cPPC]

Toshiba LTM09C035L
It's possible some had LCDs from other manufacturers though (like Sharp), so best to double check.
For future reference: https://www.macdat.net/macintosh/powerbook/general/powerbooklcdindex.html

 

[dr_hoads]

Just yesterday I opened up my 2300c because it was struggling to boot (similar symptoms as yours). My mission was to remove the dead PRAM battery because I think I read that on these models a dead one can prevent boot and of course also leak causing corrosion. I did that, and it worked booted right up.

I am also curious about the internal SCSI cable. I have two Duo 230s that I could possibly salvage a cable from. Getting a BlueSCSI v2 with WiFi would be super cool for this one. I can report back on this, but it's going to be a little bit till I get around to it.
I'm also going to try and repair the broken hinge mounts as seen on TDNC (

).

 

[dr_hoads]

OK, so I got as far as confirming the internal SCSI connector from a Duo 230 does indeed fit in the 2300c, implying as above that you could use a SCSI (and BlueSCSI v2) drive in it. See photo. I wish I could test it further but I couldn't get it to boot up...



My issue is, despite saying I fixed my boot up problem, the unit booted about 1 of 20 times. Even with the IDE drive installed. I think it might need those new caps as noted above too, but no sign of leaking or damage. What I did see potentially damaged was a chip or other component on the board looked like the legs were disconnected. Curious what others have seen on their 2300c's. Any idea what the component does or if it is indeed damaged?

 

[3lectr1cPPC]

Those legs just look like they're bent backwards, I think that's fine.
Only booting one in 20 times is textbook bad capacitors. Get 'em changed and it should be stable again, hopefully. They don't have to look bad to be bad.