General Category > Lisa Troubleshooting and Repair
New Lisa Build does not work - please help
aihk:
I'm sorry, but I don't have a LISA that works. Lisa that I built myself. I recently had time to test again, I used a 256K RAM into the 1# slot and there was a buzzer sound, if I plugged the RAM into the 2# slot I uploaded two buzzer sounds, I'm not sure if it's a problem with all the monochrome RAM slot wiring, or if it's caused by other board influences
sigma7:
--- Quote from: aihk on April 03, 2025, 04:41:22 am ---I used a 256K RAM into the 1# slot and there was a buzzer sound, if I plugged the RAM into the 2# slot I uploaded two buzzer sounds
--- End quote ---
The original Sun Remarketing SIMM RAM board (that your memory board seems to be a clone of), requires 256K x 9 SIMMs, installed in pairs. So if your design is the same, you would need to install two 256K x 9 SIMMs in the two sockets labelled "MEM1".
--- Quote ---I'm not sure if it's a problem with all the monochrome RAM slot wiring, or if it's caused by other board influences
--- End quote ---
Troubleshooting a new build is somewhat different from repairing a computer that used to work, as there are many more possible problems compared to looking for a formerly working part that has failed... for example you may have a missing trace, an open trace, a shorted trace, a wrong part, the wrong type of a correct part (eg. 74LS283 instead of 74F283), a part installed the wrong way, a missing solder joint, a solder bridge, etc.
If all of your boards are new untested builds, then you have all of those possible problems on each board, and may have multiple problems to find. The problem(s) can be solved, but it may be a lot of work to track down each one, hence the great value in being able to eliminate some possibilities by trying each of your boards in a working Lisa to see if some work ok... it will be worth the effort to find someone local to you that has a Lisa.
Here are some suggestions:
- Carefully review the sites and forums (for each board design you used) to check for known problems & documented fixes (and if there are any that apply, proceed with those fixes)
- Double check that every part is the correct family of the part type, and installed in the correct orientation
- Double check that every solder joint has been made - since a skipped solder joint is easy to miss, it is worth doing this a few times with each board, in different orientations with different lighting angles
Since this isn't the same problem as the first post in this topic (where the computer worked fine, until a particular I/O Board was installed, at which point the CPU access to memory was interrupted), I'll move it to a separate topic.
edit: clarified "MEM1" vs #1
sigma7:
--- Quote ---... suggestions
--- End quote ---
Also look carefully for IC pins that are not in their socket... eg. bent under the chip, or outside of the socket. Pins bent under are often hard to see, so again look at different angles, preferably with magnification.
Also, it is unclear if the red boxes are indicating something... if so, please clarify.
edit: question about red boxes
aihk:
--- Quote from: sigma7 on April 03, 2025, 04:57:37 pm ---
--- Quote ---... suggestions
--- End quote ---
Also look carefully for IC pins that are not in their socket... eg. bent under the chip, or outside of the socket. Pins bent under are often hard to see, so again look at different angles, preferably with magnification.
Also, it is unclear if the red boxes are indicating something... if so, please clarify.
edit: question about red boxes
--- End quote ---
The red box makes a beep when I only plug in one memory module, and if I insert the memory module into a slot that is not a red box, it will turn on the phone with two buzzers.
I'm very sorry, English is not my native language, I use machine translation, please forgive me
sigma7:
--- Quote from: aihk on April 04, 2025, 03:13:35 am ---English is not my native language, I use machine translation
--- End quote ---
That is ok. I will try to write accordingly. Please ask for clarification or another written expression if the translation is not clear to you.
It may help to say what language(s) you understand best. I can test translating, then back to english, to see how the meaning changes.
--- Quote ---The red box makes a beep when I only plug in one memory module, and if I insert the memory module into a slot that is not a red box, it will turn on the phone with two buzzers.
--- End quote ---
The memory board will NOT work with 1 module. Please install 2 memory modules in the same positions as in your video "IMG_7302". The two white sockets are marked MEM1.
Did you test with the I/O Board removed/missing? Was there any image on the screen? If so, was the image changing or steady/static?
Do you understand the suggestions to check if the parts are correct and all pins soldered?
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