View source for Sinclair ZX spectrum 48K

{{WikipediaInfoAlt|https://en.wikipedia.org/wiki/ZX_Spectrum}}

{{InfoboxDevice
|Title = Sinclair ZX spectrum 48K
|Picture =Spectrum top.jpg 
|Release Year = Introduced 1982
Discontinued 1992
|Mounting Technology = Through Hole and Sockets
|Capacitor Types = Aluminum Electrolytic
|Destructive Entry = No
|CPU=Zilog Z80A 3.5Mhz|Memory=48K|Memory Type=4116 DIP|Storage=Cassette recorder.|Display Interface=RF analogue (PAL)|Sound=Piezo speaker|Input Voltage=9V DC|Current=1.4A}}
== Known Issues ==

=== Symptom or Problem Encountered ===

====Causes====
*Keyboard non functional
====Solutions====
*Replaced decayed keyboard membrane

== Disassembly Notes ==

=== Opening the case ===
Firstly undo the 5 Philips head screws on the bottom then carefully lift the top case off while mindful of the keyboard ribbons as these can easily get torn. 

=== Removing the keyboard membrane ===

* To remove the old keyboard membrane after you have removed the top part of the case use a heat gun on the lowest setting to loosen up the adhesive under the metal plate to help prevent damage to the metal cover.
* After removing the metal plate lift the rubber key mat off the shell and then slide the old membrane out.
* To reassemble follow the steps in reverse and reattach the metal plate with new double sided tape. 

== Original Parts ==
=== Mainboard ===
''This is the list for a issue two 48K PCB''
{| class="wikitable sortable"
|+Capacitor [[Capacitor Specifications|Specifications]] and  [[Part Footprints|Footprint]] Information
!RefDes
!Qty
!Capacitance
!Voltage
![https://caps.wiki/wiki/Part_Footprints Mount]
!Diameter/Size
!Height
!Lead Spacing
!Temp
![https://caps.wiki/wiki/Capacitor_Types Type]
!Brand
!Series
|-
|C25, C28, C34, C47, C50
|5
|22µF
|10v
|Axial
|
|
|
|0 °C
|Aluminium electrolytic
|
|
|-
|C46, C27
|2
|1µF
|50v
|Axial
|
|
|
|
|Aluminium electrolytic
|
|
|-
|C44, C45
|2
|100µF
|16v
|Axial
|
|
|
|
|Aluminium electrolytic
|
|
|}


''This is the list for a issue 6A 48K PCB''
{| class="wikitable"
|+Capacitor [[Capacitor Specifications|Specifications]] and  [[Part Footprints|Footprint]] Information
!RefDes
!Qty
!Capacitance
!Voltage
![https://caps.wiki/wiki/Part_Footprints Mount]
!Diameter/Size
!Height
!Lead Spacing
!Temp
![https://caps.wiki/wiki/Capacitor_Types Type]
!Brand
!Series
|-
|C25, C28, C34, C50, C65, C80
|6
|22µF
|10v
|Axial
|
|
|
|
|Aluminium electrolytic
|
|
|-
|C74
|1
|4.7µF
|6v
|Axial
|
|
|
|
|Aluminium electrolytic
|
|
|-
|C27, C46, C79
|3
|1.0µF
|50v
|Axial
|
|
|
|
|aluminium electrolytic
|
|
|}

==Replacement Parts==
===Mainboard===
Issue two 48K
{| class="wikitable sortable"
|+
Capacitors
!RefDes
!Qty
!Compatible Part Number
!Order Links
|-
|C25, C28, C34, C47, C50
|5
|226TTA035M
|[https://www.digikey.com/en/products/detail/cornell-dubilier-illinois-capacitor/226TTA035M/5411671 DigiKey] [https://www.mouser.com/ProductDetail/Cornell-Dubilier-CDE/226TTA035M?qs=3tP%252BN51vMXc11%252BNWGOKmzw%3D%3D Mouser]
|-
|C46, C27
|2
|105TTA050M
|[https://www.digikey.com/en/products/detail/cornell-dubilier-illinois-capacitor/105TTA050M/5410603 DigiKey] [https://www.mouser.com/ProductDetail/CDE-Illinois-Capacitor/105TTA050M?qs=UG%2F8xqv%2F6WfG1nPz8JgKXw%3D%3D Mouser]
|-
|C44, C45
|2
|107TTA025M
|[https://www.digikey.com/en/products/detail/cornell-dubilier-illinois-capacitor/107TTA025M/5343978 DigiKey] [https://www.mouser.com/ProductDetail/Cornell-Dubilier-CDE/107TTA025M?qs=3tP%252BN51vMXf2HTCReIRm4Q%3D%3D Mouser]
|}


Issue 6A 48K
{| class="wikitable sortable"
|+
Capacitors
!RefDes
!Qty
!Compatible Part Number
!Order Links
|-
|C25, C28, C34, C50, C65, C80
|6
|226TTA035M
|[https://www.digikey.com/en/products/detail/cornell-dubilier-illinois-capacitor/226TTA035M/5411671 DigiKey] [https://www.mouser.com/ProductDetail/Cornell-Dubilier-CDE/226TTA035M?qs=3tP%252BN51vMXc11%252BNWGOKmzw%3D%3D Mouser]
|-
|C74
|1
|475TTA050M
|[https://www.digikey.com/en/products/detail/cornell-dubilier-illinois-capacitor/475TTA050M/5412738 DigiKey] [https://www.mouser.com/ProductDetail/Cornell-Dubilier-CDE/475TTA050M?qs=3tP%252BN51vMXdn7LI1ODkIcw%3D%3D Mouser]
|-
|C27, C46, C79
|3
|105TTA050M
|[https://www.digikey.com/en/products/detail/cornell-dubilier-illinois-capacitor/105TTA050M/5410603 DigiKey] [https://www.mouser.com/ProductDetail/CDE-Illinois-Capacitor/105TTA050M?qs=UG%2F8xqv%2F6WfG1nPz8JgKXw%3D%3D Mouser]
|}


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

===Kits===
* Digikey BOM: https://www.digikey.com/

== Related Links ==

* https://spectrumforeveryone.com/wp-content/uploads/2017/08/ZX-Spectrum-Service-Manual.pdf

== References ==
<references />

[[Category:WorkNeeded:General]]
[[Category:WorkNeeded:OriginalParts]]
[[Category:Computer]]
[[Category:1980s]]
[[Category:Sinclair]]
[[Category:Microcomputer]]