The Z148 was Zenith Data Systems' unsuccessful entrylevel PC, from 1985 to 1987. I explain its history, replace the failed Rifa capacitors in mine, give an overview of its design, and show it in operation.

Time flow:
0:00 Introduction
0:42 Zenith Z148 history
3:14 Teardown
4:20 Roasted Rifa capacitors
8:56 CPU board
10:45 I/O board
12:32 System timing
13:55 Upgrades
15:41 Powerup & Zenith quirks
18:55 Floppy drives
20:28 MSDOS in only 256K?
22:02 Keyboard
23:26 Zenith's nadir
24:06 A cure for upgraditis

Relevant videos:

BBC Micro X2 EVOX RIFA capacitors going POP
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RIFA AC Filter Capacitor Blowup
   • RIFA AC Filter Capacitor Blowup  

Zenith Data Systems vintage 84key AT keyboard
   • Zenith Data Systems vintage 84key AT...  

New SmartWatch+ clock module for Tandy 1000s & XTs
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Zenith eaZy PC review
   • Zenith eaZy PC review  

For more detailed technical information, here is the service manual for the Z148:
https://www.mediafire.com/folder/a416...

#zenith #rifa #capacitor