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| PowerBook 3500 video repair |
Posted by: Sideburn on 2024-03-01 18:16:26
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. |
Posted by: Hunter259 on 2024-03-01 18:19:27
Here's a front and back shot of the 3400c. Very very similar layout. |
Posted by: Sideburn on 2024-03-01 18:24:51
Here's a front and back shot of the 3400c. Very very similar layout. Ahh totally different RAM though... |
Posted by: 3lectr1cPPC on 2024-03-01 18:33:26
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. |
Posted by: 3lectr1cPPC on 2024-03-01 18:35:07
Service Source also says 2MB, weird. Page 29. |
Posted by: Hunter259 on 2024-03-01 18:37:08
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. |
Posted by: 3lectr1cPPC on 2024-03-01 18:39:03
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. |
Posted by: Sideburn on 2024-03-01 18:47:29
You think these would work on the kanga board?
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Posted by: Hunter259 on 2024-03-02 08:11:20
While I wouldn't guarantee it, they do seem to be compatible on the surface. Hopefully someone else can confirm. |
Posted by: Sideburn on 2024-03-02 08:17:51
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? |
Posted by: Sideburn on 2024-03-08 22:53:13
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… |
Posted by: Sideburn on 2024-03-08 23:26:20
Omg! I reflowed it and it’s fixed! |
Posted by: Zed on 2024-03-09 04:33:55
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? 😂 |
Posted by: Zed on 2024-03-09 04:44:03
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 |
Posted by: Sideburn on 2024-03-09 07:11:47
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. |
Posted by: Zed on 2024-03-29 21:57:09
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? |
Posted by: d3jsp on 2025-12-23 22:53:53
did you get it completely fixed? Was it the vram? |
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