You are not logged in.

#1 2014-06-12 19:58:15

max1zzz
Member
Registered: 2014-05-18
Posts: 207
Website

Mac IIx Powers up then cuts out

So, finally got around to recapping the second IIx (The one with the "seed1" board)

Currently It powers on for 10 seconds or so then cuts out, I get no chime and nothing on screen

The board looks OK and had a very very small amount of battery leakage, Although some via's and traces look pretty awful they all cheack out ok (I will be running wires for a few regardless as there are a few really bad looking via's)

Anyone got any ideas what i should be checking next? Also if anyone has the Schematics they would be useful to have

Offline

#2 2014-06-13 01:40:46

techknight
Member
Registered: 2014-05-22
Posts: 449

Re: Mac IIx Powers up then cuts out

Yea, find out where the vias are going onto the inner layers. Testing from a component pin to the Via isnt good enough, you have to test through the via into other planes. Not sure about that board but some inner layers carry more than just the power/ground plane, sometimes they carry signals but rare.

Last edited by techknight (2014-06-13 01:41:15)

Offline

#3 2014-06-13 09:06:22

max1zzz
Member
Registered: 2014-05-18
Posts: 207
Website

Re: Mac IIx Powers up then cuts out

I have been testing them to the other side of the board (I usually trace it back to another point that goes through the board, then test between that and whatever the via connects to)

How do you figer out what other layers they are connected to? this is where Schematics would be useful....

Offline

#4 2014-06-13 17:19:08

techknight
Member
Registered: 2014-05-22
Posts: 449

Re: Mac IIx Powers up then cuts out

Different lighting conditions would help with that

Offline

#5 2014-06-14 22:20:07

max1zzz
Member
Registered: 2014-05-18
Posts: 207
Website

Re: Mac IIx Powers up then cuts out

Ok, a bright light seems to work ok, but it is still difficult to tell

I think i'm gonna go over the power circuitry tomorrow - as i don't see why it should be cutting out even if there are broken traces elseware

This is gonna take a while.....

Offline

Board footer

About ThinkClassic

ThinkClassic specialises in the maintenance, repair, restoration and modification of Vintage Apple and Macintosh computers. Ask questions and find answers about classic Apple desktops, laptops, accessories and peripherals.