AST-3G Plus II

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This device is in the WorkNeeded:OriginalParts category because it was flagged as missing information on the original parts. It may have replacement parts listed but those cannot be assumed to be identical to the originals. If you have a list of the original parts, please feel free to add them by copying the relevant table from EditorsToolbox:Tables
This device is in the WorkNeeded:General category because it was flagged as missing general information about the device. The information may be incomplete, using default text, or inaccurate and should be verified with external sources if possible. If you can add or correct information on this page, please feel free to edit it and do so.
AST-3G Plus II
Preliminary Information
Release Year 1987
Leak Risk Medium
Batteries None
Mounting Technology Through Hole
Capacitor Types Aluminum Electrolytic, MLCC
Destructive Entry No

Jumper settings and other info here

Known Issues

Three electrolytic capacitors are leaking, try to replace

Causes

  • Produced in 1987, electrolytic capacitors are prone to leakage

Solutions

  • Recapping

Disassembly Notes

The leaked electrolyte corrodes and causes solder oxidation, which makes it difficult to desolder. Be careful to avoid high temperature damage to the pad

Original Parts

AST-3G Plus II (C)AST 1987, FCC ID: DJK 68Y AST3G

PCB Mark: 202161-303A Silkscreen: 202161-003

Capacitor Specifications and Footprint Information
RefDes Qty Capacitance Voltage Mount Diameter/Size Height Lead Spacing Temp Type Brand Series
Others 23 100 pF Through Hole 2.0 mm MLCC 104
C35 1 2.2 pF Through Hole 2.0 mm MLCC 222
C26, C27, C28, C29, C30, C31, C32, C33 8 47 nF Through Hole 2.0 mm MLCC 47K
C1, C2, C3 3 22 µF 16 V Through Hole 5 mm 5 mm 2.0 mm 85 °C Aluminum electrolytic ELNA 018 H
Integrated Circuits
RefDes Qty Model Number/Part Number Manufacturer (If Applicable) Explanation Datasheet
U1, U2, U3, U4, U5, U6, U7, U8 8 KM41C464P-10 Dynamic RAM Can't Find
U9 1 P82C435 CHIPS Enhanced Graphics Controller Link Other Link (click link, then click the download icon)
U11, U12, U13 3 DM74LS244N Octal 3-State Buffer/Line Driver/Line Reciever DM74LS244
U16 1 74LS153N Dual 4-Line to 1-Line Data Selectors/Multiplexers SN74LS153
U17 1 74LS151N DM74LS151
U18 1 SN74LS4AN Motorola SN74LS4A

Replacement Parts

0805 SMD 22uF 16V - 50V 10%

The lead spacing is too limited, I'd like use SMD on back of PCB where the through holes are filled with solder.

Capacitors
RefDes Qty Compatible Part Number Order Links
Digikey

Through Hole Capacitors

Capacitors
RefDes Qty Compatible Part Number Order Links
C1, C2, C3 3 ECE-A1CKS220 / 25MH522MEFCT56.3X5 DigiKey Mouser LCSC
Integrated Circuits
RefDes Qty Compatible Part Number Order Links
U11, U12, U13 3 SN74LS244N DigiKey Mouser LCSC
U16 1 SN74LS153N DigiKey Mouser LCSC
U17 1 SN74LS151N DigiKey Mouser LCSC

If parts are not available or different selection is preferred, you can use the values in the Original Parts section to perform a parametric search.

Kits

Related Links

References