- VR1: +12V Regulator: LM342-P-12 (Listed in manual as +15V LM342-P-15, but there is probably as +12V Regulator installed)
- VR2: +10V Regulator: LM342-P-10
- VR3: +5V Regulator: UA78GU1C and TIP31
- VR4: -5V Regulator: LM320 MP or 7905C
- U1: ROM: 9316B HVSA
- U2: ROM: 9316B HVSB
- U3: ROM: 9316B HVSC
- U4: ROM: 9316B HVSD
- U5: 74LS367
- U6: 74LS04
- U7: CPU: Z80
- U8: 74LS257
- U9: 74LS257
- U10: DP8304
- U11: 74LS02
- U12: 74LS00
- U13: 74LS10
- U14: 74LS10
- U15: 74LS02
- U16: 74LS74
- U17: Address IC: 0066-115XX-XXYX
- U18: Data IC: 0066-116XX-XXYX
- U19: IO IC: 0066-117XX-XXYX
- U20: 74LS174
- U21: 74LS74
- U22: 74LS74
- U23: DM81LS95
- U24 - U31: RAM 4096 or 4027
- U32: 75361AP
Quick Voltage Reference
The Astrocade uses 4 different voltages with no clear test points for taking measurements. The pictures below show a few places to take measurements and the locations of the regulators.
Heat is a notorious killer of Astrocade consoles due to air circulation problems.
An Astrocade should never be left on a carpeted surface, or in any location where heat cannot convect through and away from the console.
Inside, a large bank of chips is covered by RF shielding. Many Astrocade owners opt to improve airflow by removing this shielding. In a peculiar design choice, attached to that shielding is a "heat sink" for one of the 40-pin DIP chips. I put heat sink in quotes because it's really just a bar of metal with no cooling fins. (We have upgraded heat sinks that are more effective)
If the shielding is removed, a proper heatsink and thermal compound should be used on that chip. Even if you don't remove that shielding, a proper heatsink wouldn't hurt.
A080-90701-B620 C1 1500uF 25V C6 10000uF 10V C7 15uF 25v C8 15uF 25v C10 100uF 16V C13 1uf 50v C62 15uF 25v C63 15uF 25v C64 15uF 25v NOTE: For our cap kits we substitute 22uF in place of the 15uF.
Note that the 15uF parts may be black tantalum capacitors. Later revisions of the Astrocade feature electrolytic capacitors. You might consider replacing the tantalum caps with electrolytic as tantalum caps are also prone to failure.