Mac SE 2 FD - patterns

[ApfelKlassik.de]

Hi,
anyone having a quick shot on the reason of those patterns on startup?

Firstly there's this ons ...

and ofter a few seconds it switches to

(RAM has already be switched to known-good ... board is recapped (IIRC ) and washed)

 

[Nixontheknight]

Hi,
anyone having a quick shot on the reason of those patterns on startup?

Firstly there's this ons ...


View attachment 12148

and ofter a few seconds it switches to

View attachment 12150

(RAM has already be switched to known-good ... board is recapped (IIRC ) and washed)

try reseating the ROM, or try putting deoxit on the RAM and ROM sockets and see if the behavior changes

 

[Volvo242GT]

Also check the BBU chip for damage.

See here: https://68kmla.org/bb/index.php?threads/two-ses-accessories-300.44216/page-6

-J

 

[ApfelKlassik.de]

Thanks for the hints!

ROM reseated and pins brushed with fibre-glass in-between - no change.
(Will have to order some Deoxi ... but RAM itself was Ultrasonic'ed+, contacts fibre-glass pencilled - so it only can be the sockets)

BBU no visible damage outside - removed - no visible damage, contacts fibre-brushed & reseated - no change. ...

 

[Volvo242GT]

Any change in display patterns if you wiggle the harness between the analog board and the logic board? My old SE would randomly display a checkerboard pattern. Found that one or two of the wires in the harness were losing connection when it'd do the checkerboard pattern. Thought it was the usual bad solder joints, but the problem moved to the other end of the harness when I flipped it around.

 

[ApfelKlassik.de]

Wiggling no effect - Deoxi no effect ... maybe the ROM is defective?