I checked all the vias underneath the battery — they're all good. But I'm not entirely sure the new F258s are installed the right way, since there were no markings on them.Since you had battery damage I would check continuity of all your data / address lines. . Start with your rom socket to cpu. Seen a number of issues there. After that I would check everything going from rom socket to the mux'. There is a pin to pin matrix that someone was nice enough to make at the end of the schematics. That will make it easy for you quickly verify what pins to test.
I checked all the vias underneath the battery — they're all good. But I'm not entirely sure the new F258s are installed the right way, since there were no markings on them.
There’s no marking or anything on the chips, even under the microscope.Got a photo?
They’re usually tapered on one side - the side that has pin one.
I used F258AD, not F258. They’re from Philips.There’s no marking or anything on the chips, even under the microscope.
All of the chips have a bevel on one edge, including the ones that have lost their markings.There’s no marking or anything on the chips, even under the microscope.
I swear, there’s nothing on the new F258AD from Philips ! I looked under the microscope !All of the chips have a bevel on one edge, including the ones that have lost their markings.
Okay !!! Sorry, I feel a bit stupid right now. But at least they're correctly in place. The Mini-din 8 to serial cable is coming home...
Unfortunately, no. The ultrasonic baths didn't change a lot. This morning I checked almost every traces around the battery, the copro and the muxes, they're all fine ! Even the vias !do you have a photo before the repairs/ ultrasonic cleanings? it helps locating spots for clues
Found thatUnfortunately, no. The ultrasonic baths didn't change a lot. This morning I checked almost every traces around the battery, the copro and the muxes, they're all fine ! Even the vias !
I'm having a difficult time with the Test Mode too. Was able to get the Transmit Line Feed, and Local echo setup in the Terminal tab of Tera Term, it looks like it behaves and works correctly now when pressing *A and *5, but I get no answer from an SE or SE/30, using my newer PC and Prolific USB/COM port adapter. I also never get the Sad Mac screen/tone while connected via TeraTerm, or when pressing the Reset or NMI either.Found that
I tried to use the “hidden test mode”, but I cannot type anything on the terminal. I was using Tera Term with the good settings (9600 baud, 8 bits, 2 bits stop, no flux). Same thing on a working machine in crash state, so my mini din-8 to serial cable might be bad. Apparently some cables are not connected.
I ordered an other one, hopefully it works.


I also never get the Sad Mac screen/tone while connected via TeraTerm, or when pressing the Reset or NMI either.
Thanks! I bought that one :It needs to be wired as a null modem - DB9 null modem adapters are available. This is pinout of my working TechStep cable - I originally made it as a cable for ADTPro software for Apple IIgs:
View attachment 85420
Really ? I'll be able to communicate with it ? I thought it wasn't possible. Which software should I use ?You can also just connect up to another Mac with a regular DIN-8 to DIN-8 serial cable.