---
title: "How to Have a Reliable QL"
type: "article"
slug: "how-to-have-a-reliable-ql-2"
url: "http://localhost/article/how-to-have-a-reliable-ql-2/"
markdown_url: "http://localhost/article/how-to-have-a-reliable-ql-2.md"
published_at: "2026-03-13T18:37:55+00:00"
modified_at: "2026-03-13T18:37:55+00:00"
featured_image:
  url: "http://localhost/wp-content/uploads/2022/04/20230809-041332.jpg"
excerpt: "Describes a series of hardware modifications to improve QL reliability, including voltage regulator replacement, bypass capacitors at the 8301, 8302, and 8049 chips, a shunt resistor modification, and an EPROM ROM upgrade using Sharp's MG ROM. Also covers replacing the Hermes 8749 chip to address common failure modes. An essential reference for QL hardware maintenance."
category:
  - name: "The RAMTOP"
    slug: "the-ramtop"
    taxonomy: "category"
    url: "http://localhost/category/periodicals/the-ramtop/"
post_tag:
  - name: "Hardware project"
    slug: "hardware-project"
    taxonomy: "post_tag"
    url: "http://localhost/tag/hardware-project/"
  - name: "QL"
    slug: "ql"
    taxonomy: "post_tag"
    url: "http://localhost/tag/ql/"
model:
  - name: "Sinclair QL"
    slug: "sinclair-ql"
    taxonomy: "model"
    url: "http://localhost/model/sinclair-ql/"
indiv:
  - name: "John Impellizzeri"
    slug: "john-impellizzeri"
    taxonomy: "indiv"
    url: "http://localhost/indiv/john-impellizzeri/"
publication_r:
  id: 39272
  title: "The RAMTOP"
  type: "periodical"
  url: "http://localhost/periodical/the-ramtop/"
authors_r:
  - name: "John Impellizzeri"
    slug: "john-impellizzeri"
    taxonomy: "indiv"
    url: "http://localhost/indiv/john-impellizzeri/"
issues_articles:
  - id: 50276
    title: "The RAMTOP Winter 1993"
    type: "issue"
    url: "http://localhost/issue/the-ramtop-winter-1993/"
pages: "2"
pubdate: "Winter 1993"
archive_link: false
---

# How to Have a Reliable QL

Describes a series of hardware modifications to improve QL reliability, including voltage regulator replacement, bypass capacitors at the 8301, 8302, and 8049 chips, a shunt resistor modification, and an EPROM ROM upgrade using Sharp’s MG ROM. Also covers replacing the Hermes 8749 chip to address common failure modes. An essential reference for QL hardware maintenance.