PowerBook 3500 video repair

[Sideburn]

Mac Gurus and Low End Mac report the 3400c as having 1MB and based on the board layout that makes sense. To say I'm a bit confused would be an understatement.

The 3400c uses different pin spacing from the kanga so it's unlikely to be able to use them.

I saw that as well and also confused. I wish I could just find the chips.

 

[Hunter259]

Here's a front and back shot of the 3400c. Very very similar layout.

 

[Sideburn]

Here's a front and back shot of the 3400c. Very very similar layout.

Ahh totally different RAM though...

 

[3lectr1cPPC]

Mac Gurus and Low End Mac report the 3400c as having 1MB and based on the board layout that makes sense. To say I'm a bit confused would be an understatement.

Mactracker and everymac both report 2MB. If the chips themselves come out to just 1MB then I'll update my website's spec table.

 

[3lectr1cPPC]

https://www.macdat.net/files/pdf/servicesource/powerbook_3400_g3-kanga.pdf

Service Source also says 2MB, weird. Page 29.

 

[Hunter259]

https://www.macdat.net/files/pdf/servicesource/powerbook_3400_g3-kanga.pdf

Service Source also says 2MB, weird. Page 29.

I saw that too but when they take the 3400 board out you can see it matches mine and the datasheet (https://www.datasheetcatalog.com/datasheets_pdf/K/M/4/1/KM416V254DJ-6.shtml) reports them as 256k x 16bit for 1MB of vram. 800x600 at 16bit color just barely fits in that frame buffer.

 

[3lectr1cPPC]

What about external output? Can it do higher than that?

Edit: Appears external VGA out is limited to 800x600 mirrored mode only. I guess it does only have 1MB then, given the chips. I'll update my website.

 

[Sideburn]

You think these would work on the kanga board?

https://www.mouser.com/ProductDetail/ISSI/IS41LV16256C-35TLI?qs=NHTRUjBBRiPscTKwmG8dJA%3D%3D

 

[Hunter259]

While I wouldn't guarantee it, they do seem to be compatible on the surface. Hopefully someone else can confirm.

 

[Sideburn]

Also wondering if I could lift a bank of ram and see if the issue changes or improves to maybe confirm that it is indeed a vram issue.

And if so how can I tell which two are a bank?

 

[Sideburn]

Well shoot. Just spent hours replacing the vram and same problem. But worse. May be incompatible ram in some way or I have a bad solder connection but it looks good to me. Regardless it’s apparently not the vram.

If anyone has any ideas please let me know. I don’t think there are any schematics out there…

 

[Sideburn]

Omg! I reflowed it and it’s fixed!

 

[Zed]

I have the exact same problem. Started my 3400c today after it being in the cupboard for a few years and getting the same issue. when I change the mode to 256 colors I get less issues. Feel like doing another?

 

[Zed]

This look similar to what you were getting? When I connect external display I get the same output. Tried reseating everything. Cleaning etc. but no different. Where did you get the vram from? Mine is a 3400c 240

 

[Sideburn]

This look similar to what you were getting? When I connect external display I get the same output. Tried reseating everything. Cleaning etc. but no different. Where did you get the vram from? Mine is a 3400c 240

Well unfortunately the issue came back. I haven’t figured it out yet. It’s rather applying head fixes it temporarily for I can’t get a good connection on the board to all 4 rams. I kept working on it all night and made things worse. Going to go through all connections carefully and hopefully get it back to working.

Got the ram from mouser there’s a link a few posts back.

 

[Zed]

Well unfortunately the issue came back. I haven’t figured it out yet. It’s rather applying head fixes it temporarily for I can’t get a good connection on the board to all 4 rams. I kept working on it all night and made things worse. Going to go through all connections carefully and hopefully get it back to working.

Got the ram from mouser there’s a link a few posts back.

How did you go Sideburn? Still getting the issue?

 

[d3jsp]

did you get it completely fixed? Was it the vram?