68kMLA Classic Interface
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| Click here to select a new forum. | | Macintosh Classic II -12V problems. | Posted by: thiagofalencar on 2021-12-09 08:05:47
Hi! I'm in Odyssey to fix my Macintosh Classic II, now I have no image and no bip.
Problems identified and not fixed yet:
- The LM317T is heating a lot and beating more than 150 celsius and was already replaced.
- The -12V is under -3V (checked in the pin 6 in the DB-19 connector)
Components replaced:
- All electrolytic capacitors (except the 2 big ones)
- LM317T (1.2 V to 37 V adjustable voltage regulators)
- IRFBC40 (N - CHANNEL 600V - 1.0Ω - 6.2 A - TO-220 PowerMESH MOSFET)
- DP3 e DP4 (Zener Diodes)
Main questions that I need help with!
- How do I check whats is causing the -12V is under 3V?
- How do I identify why the voltage regulator is too hot?
- Anyone has the schematic of Macintosh Classic II? | | 1 |
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