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  1. M

    Macintosh Plus R8 resistor value

    R8 is 150 Ohm
  2. M

    Macintosh Plus keeps tripping RCD

    C33 and C36 are the numbers for the international board. these are the 4700 pf line filter caps
  3. M

    Macintosh Plus keeps tripping RCD

    probable C33 and C36 these will be cracked after all the years of service and create a shortcut. you can remove the capacitors, you can test the mac without them,
  4. M

    Mac Plus screen adjustment

    Replaced the solder on CR1 and CR5 replaced C3 (old one measured 190uF instead of 220uF) Problem still the same.
  5. M

    Mac Plus screen adjustment

    Thanks for your reaction, The L3 is a coil so reversing it should have no effect, I thought also. It does have a little effect as you can see the left margin of the screen got bigger. Addes a new photo with some lines. The difference between the left and right side of the screen is >10%, it...
  6. M

    Mac Plus with Radius FPD & CPU card - Pinout Ask

    http://32by32.com/radius-full-page-display http://www.applefritter.com/?q=node/18313
  7. M

    Mac Plus screen adjustment

    Am able to influence the horizontal linearity using magnets. Put some on L3 . Still not perfect but can try other magnets or location.
  8. M

    Mac Plus screen adjustment

    R1 and L3 are the components responsable for the horizontal linearity. Measured R1, 220 ohm seems ok, L3 also ok. Noticed L3 has been reversed on the board (the glue was on the R1 side) by someone previously repairing the board? After reversing L3 back the image improved somewhat
  9. M

    Mac Plus screen adjustment

    C1 is replaced with a film cap 3.9uf 450vdc Ecw-fd2w395jb problem is the same before and after replacing C1 on this international analog board i have replaced CR15 and CR17 (zener 6v2) and R55 (33k)
  10. M

    Mac Plus screen adjustment

    Have a mac plus here with a problem. The right side of the screen seems to be compressed. Everything on the right side is a lot smaller. Does anyone know how to fix this? Already replaced C1
  11. M

    Macintosh Plus Analog Board Q12 replacement

    Maybe the following can help to understand the circuit better, is part of the powersupply schematic does anyone have the schematics for the international version of the analog board? 
  12. M

    Classic II beyond repair?

    The challenge you have is not the caps but the repair of the traces, the board will not work until you repair these. there are a number of traces which have the capacitor island in the middle so the connection is broken. Also for example the trace which runs between the islands of C5 and...
  13. M

    Macintosh Plus Analog Board Q12 replacement

    tried some other resistors, 1K5 is too much (unstable), 1K , voltages too high. 1K1 and 1K2 work this is using a BRX49, don't have other BRX4x to test. You have to regulate the 5V to get as close as possible to the desired 5V value, too high or too low => crowbar.. :unsure: Still...
  14. M

    Classic II beyond repair?

    I don't think you "need" any of the caps to boot. The most important thing is to clean the board to remove alle the leaked cap fluid. c15 connects to the pins as shown in the picture
  15. M

    Classic II beyond repair?

    I always use tantalums to recap. C15 is connected between 2 pins op 344S1033-01, if you don't connect it the sound does not work, but the mac will 
  16. M

    Macintosh Plus Analog Board Q12 replacement

    Ok , changed R50 to 1K1 (2x 2K2 piggyback) Voltages are 5.1V and 12.25V Have to find the sweet spot... :mrgreen:
  17. M

    Macintosh Plus Analog Board Q12 replacement

    Thanks for your replies. Put a 10K potmeter in place of R50, the mac is stable at 1K, so I replaced R50 with a 1K resistor. Problem is I have very little regulation on RPx to adjust the 5V, voltages are 5.2V and 12.35V Mac is working ok but don't know if this is the best solution.
  18. M

    Macintosh Plus Analog Board Q12 replacement

    Am also looking for a replacement for the E0122YA      _ _     | x |     |_ _|     | | |     | | |     1 2 3 E0122YA    (K G A) tested the foillowing replacements: BT169D     (K G A)    flupping set P0102DA    (K G A)    flupping set BRX49    (A G K)reverse!    mac starts but is not...
  19. M

    Macintosh Classic Ram problem

    does pin 4 connect to to pin 26 UI4 ? could you complete the following list so all pins are checked (don't have a schematic myself) UH6  pin 1,13,14 to pin 17 UI4 BBU pin 2 to pin 9 UL1 pin 3 to pin 15 UF3 pin 4 to pin 26 UI4 pin 5 to pin 3 UL1 pin 6 to pin 7 to pin 4 UL1 pin 9 to pin...
  20. M

    Macintosh Classic Ram problem

    Hello Macalle, you have to check the connections from the pins of UH6 all the way to the CAS PAL  UL1 and also to VLSI UI4 The must be a broken connection there In my case the connection was broken from UH6 to the via, but in your case may be somewhere else on the line.
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