{"id":1698,"date":"2022-08-20T12:52:36","date_gmt":"2022-08-20T10:52:36","guid":{"rendered":"https:\/\/dlabi.cz\/?p=1698"},"modified":"2023-12-30T00:45:07","modified_gmt":"2023-12-29T23:45:07","slug":"oprava-napajeciho-zdroje","status":"publish","type":"post","link":"https:\/\/dlabi.cz\/en\/oprava-napajeciho-zdroje\/","title":{"rendered":"Power supply repair"},"content":{"rendered":"<div class=\"wp-block-media-text alignwide is-stacked-on-mobile\" style=\"grid-template-columns:23% auto\"><figure class=\"wp-block-media-text__media\"><img decoding=\"async\" src=\"https:\/\/dlabi.cz\/data\/D01B275F-D78F-498B-80E2-894F8677EEFF.jpeg\" alt=\"\" class=\"wp-image-1700 size-full\"\/><\/figure><div class=\"wp-block-media-text__content\">\n<p>After about 30 years, the original Sord m5 power supply started delivering unstable power levels. It stabilized at the nominal voltages a few minutes after switching on. So everything pointed to dried up electrolytic capacitors. The function of the computer was mainly manifested in the instability of VDP and video memory, where character sprites were greatly altered, image synchronization was unstable and iridescent colors ran across the image. You can see the said behavior in the video below\u2026<\/p>\n<\/div><\/div>\n\n\n\n<!--more-->\n\n\n\n<div style=\"height:31px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-video\"><video height=\"720\" style=\"aspect-ratio: 1280 \/ 720;\" width=\"1280\" controls src=\"https:\/\/dlabi.cz\/data\/trim.0560C869-BDFC-4236-875B-413F8D1484CA.mov\"><\/video><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/dlabi.cz\/data\/81F22BFF-EAAF-460B-87B8-A7C124F97B7C.jpeg\" alt=\"\" class=\"wp-image-1702\"\/><\/figure>\n<\/div>\n<\/div>\n\n\n\n<p>By measuring the individual voltages, it turned out that the +12V voltage was the main culprit of the unstable image. Immediately after switching on, instead of the 12V, I measure a little over 10V. The image normalized to somewhere around 11.8V<\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/dlabi.cz\/data\/F7D47593-D851-4730-868B-0E35C49E1DD8.jpeg\" alt=\"\" class=\"wp-image-1716\" width=\"244\" height=\"325\"\/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p>Right after psu disassembly I didn\u2019t find any sign of \u201cbloated\u201d caps<\/p>\n\n\n\n<p>The repair itself is trivial and can be done by anyone who has a soldering iron at home. There are a lot of electrolytes in the psu,but I only replaced C1, C2, C5 and C8. Their values \u200b\u200bare as follows:<\/p>\n\n\n\n<figure class=\"wp-block-table is-style-regular\"><table class=\"has-white-color has-cyan-bluish-gray-background-color has-text-color has-background\"><tbody><tr><td class=\"has-text-align-right\" data-align=\"right\">C1<\/td><td class=\"has-text-align-center\" data-align=\"center\">3300uF<\/td><td>16V<\/td><\/tr><tr><td class=\"has-text-align-right\" data-align=\"right\">C2<\/td><td class=\"has-text-align-center\" data-align=\"center\">470uF<\/td><td>16V<\/td><\/tr><tr><td class=\"has-text-align-right\" data-align=\"right\">C5<\/td><td class=\"has-text-align-center\" data-align=\"center\">1000uF<\/td><td>35V<\/td><\/tr><tr><td class=\"has-text-align-right\" data-align=\"right\">C8<\/td><td class=\"has-text-align-center\" data-align=\"center\">220uF<\/td><td>35V<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:9px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright size-full is-resized\"><a href=\"https:\/\/dlabi.cz\/data\/D846A58D-2866-43CF-9D02-671236A01484.jpeg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/dlabi.cz\/data\/D846A58D-2866-43CF-9D02-671236A01484.jpeg\" alt=\"\" class=\"wp-image-1762\" width=\"271\" height=\"233\" srcset=\"https:\/\/dlabi.cz\/data\/D846A58D-2866-43CF-9D02-671236A01484.jpeg 2444w, https:\/\/dlabi.cz\/data\/D846A58D-2866-43CF-9D02-671236A01484-291x250.jpeg 291w, https:\/\/dlabi.cz\/data\/D846A58D-2866-43CF-9D02-671236A01484-768x660.jpeg 768w\" sizes=\"auto, (max-width: 271px) 100vw, 271px\" \/><\/a><\/figure>\n<\/div>\n\n\n<p class=\"has-text-align-left\">Notice how the printed circuit board is blackened under the diodes. Either as guys we played games A LOT or we overloaded the supply with various peripherals. It\u2019s true that 200mA is not much.<\/p>\n\n\n\n<p>After replacing the capacitors, the psu works as it should again. If you want your power supply to last another 30 years, I recommend you use higher quality capacitors with low ESR<\/p>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/dlabi.cz\/data\/EDD10425-2C92-4FE9-929B-EBB74F51A2D5.jpeg\"><img decoding=\"async\" data-id=\"1776\" src=\"https:\/\/dlabi.cz\/data\/EDD10425-2C92-4FE9-929B-EBB74F51A2D5.jpeg\" alt=\"\" class=\"wp-image-1776\"\/><\/a><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/dlabi.cz\/data\/6543255F-EFF8-4D9A-9EBA-EF5552C24F73.jpeg\"><img decoding=\"async\" data-id=\"1778\" src=\"https:\/\/dlabi.cz\/data\/6543255F-EFF8-4D9A-9EBA-EF5552C24F73.jpeg\" alt=\"\" class=\"wp-image-1778\"\/><\/a><\/figure>\n<\/figure>","protected":false},"excerpt":{"rendered":"<p>Zhruba po 30 letech, za\u010dal origin\u00e1ln\u00ed zdroj pro Sord m5 vykazovat nestabiln\u00ed \u00farove\u0148 nap\u00e1jen\u00ed. To se ust\u00e1lilo na jmenovit\u00fdch nap\u011bt\u00edch a\u017e po p\u00e1r minut\u00e1ch od zapnut\u00ed. V\u0161e tedy nasv\u011bd\u010dovalo na vyschl\u00e9 elektrolytick\u00e9 kondenz\u00e1tory. Na funkci po\u010d\u00edta\u010de se to projevovalo hlavn\u011b v nestabilit\u011b VDP a video pam\u011bti, kdy sprity znak\u016f byly zna\u010dn\u011b pozm\u011bn\u011bn\u00e9, synchronizace obrazu nest\u00e1l\u00e1&#8230; <\/p>\n<div class=\"read-more navbutton\"><a href=\"https:\/\/dlabi.cz\/en\/oprava-napajeciho-zdroje\/\">Read More<i class=\"fa fa-angle-double-right\"><\/i><\/a><\/div>","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[91],"tags":[119,110,19,111],"class_list":["post-1698","post","type-post","status-publish","format-standard","hentry","category-sord-m5","tag-ac-50","tag-psu","tag-sord","tag-zdroj"],"_links":{"self":[{"href":"https:\/\/dlabi.cz\/en\/wp-json\/wp\/v2\/posts\/1698","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dlabi.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dlabi.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dlabi.cz\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/dlabi.cz\/en\/wp-json\/wp\/v2\/comments?post=1698"}],"version-history":[{"count":31,"href":"https:\/\/dlabi.cz\/en\/wp-json\/wp\/v2\/posts\/1698\/revisions"}],"predecessor-version":[{"id":1780,"href":"https:\/\/dlabi.cz\/en\/wp-json\/wp\/v2\/posts\/1698\/revisions\/1780"}],"wp:attachment":[{"href":"https:\/\/dlabi.cz\/en\/wp-json\/wp\/v2\/media?parent=1698"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dlabi.cz\/en\/wp-json\/wp\/v2\/categories?post=1698"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dlabi.cz\/en\/wp-json\/wp\/v2\/tags?post=1698"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}