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CelGen

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About CelGen

  • Birthday 03/11/1990

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  • Location
    Kamloops, Canada
  • Interests
    Computers (notably Silicon Graphics systems, Apple/mac computers, and multiprocessor PC's), console collecting, photography

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  1. For reference. The schematic for the Lisa's analog board can be found here. My guess is there is a problem with the brightness adjustment. I don't know what the grid voltage is on a Lisa but 400v sounds like the potentiometer has gone open and the circuit is unloaded. The schematic shows spark gaps but I assume those only engage around 1000v.
  2. Something probably went screwy with the system software. I've seen malware from time to time but these days the clearly malicious stuff like bogus disk images have been weeded out. When you upgraded the ram in the FDHD I assume you moved the memory size jumper (newer models) or resistor? (older models) You may still very well have it set to 2mb, in which case it will not see the full 4mb and 6.0.8 can simply...run out of memory.
  3. CelGen

    New Lisa Hardware Coming

    I would like to suggest to the designer that I would be curious about the cost of purchasing unpopulated boards. The idea of transplanting components from failed boards to new boards with healthy traces sounds like an interesting prospect.
  4. CelGen

    Apple Ethernet NB - does it deliver?

    I have two A/Rose cards myself. If I recall they sold the ethernet card, a multiport serial card, a token ring card and a 3270/5250 emulation card under the standard. I've seen the first three quite regularly but I have not seen the terminal emulation card in over a decade. They must be quite uncommon. Think of that card as the 90's version of the Killer NIC. https://en.wikipedia.org/wiki/Killer_NIC
  5. CelGen

    Apple M1296 12" RGB: No Raster

    Okay then, so if the high voltage comes up and the heater lights then something is funky on your analog board.
  6. CelGen

    Apple M1296 12" RGB: No Raster

    I'm going from older knowledge here but if you can't even force the brightness up with an internal pot to see a raster check so see if the end of the tube has the orange glow of the heater. From experience one of two things has happened. Either the video stage itself has suffered a rather large failure and no signal is reaching the tube but the high voltage is good, or the cathode heater in the tube has failed, possibly from the monitor being very roughly handled or old age.
  7. Again, you are seeing a screen raster and good horizontal and vertical geometry. That indicates both the tube is good and the analog board is outputting at the absolute minimum a useable everything (it just has no video signal to show). If the boards and card cage work and give an image in another Lisa it can only mean either a problem with the wire harness or the analog card with my money on the latter. Rotate the adjustment pots on the card. Yes they may still have the blue locktite intact but that's the same thing I said. All I did was twiddle the brightness adjustment and boom, there was an image.
  8. CelGen

    Help identifying printer

    I mean, I could believe Woz signing it because he signs anything, but Steve? What kind of a forgery is this?
  9. Just plug in a (literally any) composite monitor. Again it will not sync right but you will see something resembling an image.
  10. Again, the analog card is not in the card cage. It's behind the CRT. While the refresh rate on the rear video output as I mentioned was not something standard you should still be able to make out large features on the screen. Again, the white box will be obvious and you might even be able to see the mouse cursor.
  11. Also want to add you have done a good job cleaning up the backplane and yes, the schematics for it are not available online that I have seen so far (while schematics for every other board are) but thankfully it and the I/O board which is where the battery resides are two-layer boards so there is need to worry about inner layers possibly being damaged. The dark marring on the edge connectors is fine. If in doubt give them a good rub with a pink eraser. Additionally, unless you have it already planned to do it, I suggest recapping both the power supply AND the analog board.
  12. Hi-Hi-Low as per this indicates the keyboard is unplugged and it can be clearly seen as such in the video. The grey screen with the diagonal lines is a raster. That means the analog board is working well enough that it has horizontal and vertical sweep. Before you proceed any further, take a sharpie and mark the current positions of the adjustment pots on the top of the analog board. You can see it just behind the CRT when you take the top off. Turn each pot a little to the left and to the right. I've seen them simply oxide up and the connection goes open but just disturbing the knob brings it back. Short of hacking a multisync monitor to take a composite input, the video out on the back of the Lisa is your standard composite video signal however the vertical refresh rate is non-standard and I couldn't find any conventional or professional video monitor that would sync to it.
  13. CelGen

    Board Cleaning - Techniques - Chemical Reactions

    I just wash the boards with part of a broken dustpan broom or a toothbrush under hot running water and then blast the water off with the air compressor and put them out to dry for 24 hours. Screw vinegar and wasting expensive iso.
  14. CD drives, GPS units, video editing decks, KVM switches, video cards..... Basically any device that used SMD lytics between their introduction in the 80's and 2000 (and I'm willing to bet it's going to continue for many years after as stuff now 15 years old begins to drop dead) have a 100% failure rate. Some items however you really gotta stop and think about how much it is worth to you. I have a JVC GY-X2 professional SVHS television camera. It clearly needs a recap but there are over 150 smd caps needing to be replaced. That could easily be $150 in components and many hours of work.
  15. CelGen

    Apple CD SC - Not reading disks properly??

    Perhaps the eject switch is sticking?
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