{"id":1412,"date":"2018-11-07T19:44:38","date_gmt":"2018-11-08T03:44:38","guid":{"rendered":"http:\/\/media.davebaar.com\/wordpress\/?p=1412"},"modified":"2022-12-08T21:48:05","modified_gmt":"2022-12-09T05:48:05","slug":"circa-1993-bose-clock-radio-repair","status":"publish","type":"post","link":"https:\/\/davebaar.com\/wordpress\/2018\/11\/07\/circa-1993-bose-clock-radio-repair\/","title":{"rendered":"Circa-1993 Bose Clock Radio Repair"},"content":{"rendered":"<p>One of the most interesting and challenging repairs to come my way at the recent Repair Caf\u00e9 in Campbell River, BC was a Bose clock radio. This radio had no audio output other than a loud buzz from the speakers when turned on.<\/p>\n<div id=\"attachment_1416\" style=\"width: 160px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/davebaar.com\/wp-content\/uploads\/2018\/11\/IMG_20181106_163346423.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1416\" class=\"size-thumbnail wp-image-1416\" title=\"Bose Clock Radio\" src=\"https:\/\/davebaar.com\/wp-content\/uploads\/2018\/11\/IMG_20181106_163346423-150x150.jpg\" alt=\"\" width=\"150\" height=\"150\"><\/a><p id=\"caption-attachment-1416\" class=\"wp-caption-text\">Bose Clock Radio, post-repair<\/p><\/div>\n<p><!--more--><br \/>\nThese units can be disassembled in a series of steps. The primary step is to remove the four Philips-head screws on the underside, giving access to the main circuit board.<\/p>\n<div id=\"attachment_1413\" style=\"width: 310px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/davebaar.com\/wp-content\/uploads\/2018\/11\/IMG_20181103_184513979_HDR.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1413\" class=\"size-medium wp-image-1413\" title=\"main circuit board\" src=\"https:\/\/davebaar.com\/wp-content\/uploads\/2018\/11\/IMG_20181103_184513979_HDR-300x168.jpg\" alt=\"\" width=\"300\" height=\"168\"><\/a><p id=\"caption-attachment-1413\" class=\"wp-caption-text\">main circuit board<\/p><\/div>\n<p>Most of the other cover components can be snapped into and out of place by pressing on tabs with a standard screwdriver. One of the first things I checked was the large primary power supply capacitor; that was fine and was not the cause of the problem. In this case, another symptom was that the LED display worked, but had a significant visible flicker at about 8Hz. After some tests of 3 electrolytic capacitors on the display circuit board, one turned out to be bad, and I replaced that with a known good 47uF 50V near-equivalent part. The replaced part is the grey capacitor in the lower right in the photo below. That fixed the problem entirely, and after reassembly, the radio is functioning normally &#8211; very impressive audio by Bose from such a compact radio.<\/p>\n<div id=\"attachment_1414\" style=\"width: 310px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/davebaar.com\/wp-content\/uploads\/2018\/11\/IMG_20181106_155155529.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1414\" src=\"https:\/\/davebaar.com\/wp-content\/uploads\/2018\/11\/IMG_20181106_155155529-300x168.jpg\" alt=\"\" title=\"replaced capacitor\" class=\"size-medium wp-image-1414\" width=\"300\" height=\"168\"><\/a><p id=\"caption-attachment-1414\" class=\"wp-caption-text\">replaced capacitor in display driver circuitry<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"<p>One of the most interesting and challenging repairs to come my way at the recent Repair Caf\u00e9 in Campbell River, BC was a Bose clock radio. This radio had no audio output other than a loud buzz from the speakers when turned on.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1412","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/davebaar.com\/wordpress\/wp-json\/wp\/v2\/posts\/1412","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/davebaar.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/davebaar.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/davebaar.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/davebaar.com\/wordpress\/wp-json\/wp\/v2\/comments?post=1412"}],"version-history":[{"count":2,"href":"https:\/\/davebaar.com\/wordpress\/wp-json\/wp\/v2\/posts\/1412\/revisions"}],"predecessor-version":[{"id":1684,"href":"https:\/\/davebaar.com\/wordpress\/wp-json\/wp\/v2\/posts\/1412\/revisions\/1684"}],"wp:attachment":[{"href":"https:\/\/davebaar.com\/wordpress\/wp-json\/wp\/v2\/media?parent=1412"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/davebaar.com\/wordpress\/wp-json\/wp\/v2\/categories?post=1412"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/davebaar.com\/wordpress\/wp-json\/wp\/v2\/tags?post=1412"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}