{"id":2812,"date":"2016-05-28T15:15:35","date_gmt":"2016-05-28T22:15:35","guid":{"rendered":"http:\/\/www.dognmonkey.com\/audi\/?p=2812"},"modified":"2024-09-18T13:41:03","modified_gmt":"2024-09-18T20:41:03","slug":"an-open-circuit-test-on-mmi-2g-most-bus-and-vcds-read-out-results","status":"publish","type":"post","link":"https:\/\/www.dognmonkey.com\/audi\/an-open-circuit-test-on-mmi-2g-most-bus-and-vcds-read-out-results.html","title":{"rendered":"An Open-Circuit Test On MMI 2G MOST Bus and VCDS Read Out Results"},"content":{"rendered":"<p><em>Audi MMI 2G &amp; 3G MOST bus is very simple but yet very hard to\u00a0<\/em><i>diagnose which components connected to the bus is faulty due to the serial optical connections. If the system is not\u00a0thoroughly tested and diagnosed, many good parts can be replaced in the process.\u00a0This is a simple test just show that an open circuit caused the system looked bad and VCDS report shows many non related failures.<\/i><\/p>\n<p style=\"text-align: center;\"><em>If the head unit 4E0 035 729 failed, I would check all the Polarized capacitors for short, burnt (bulging top).<\/em><\/p>\n<p style=\"text-align: center;\">I could see <a href=\"\/\/www.ti.com\/product\/lp3965?HQS=TI-null-null-sf-df-pf-SEP-wwe\" target=\"_blank\" rel=\"noopener noreferrer\">drop down voltage regulator (LP3965ES)<\/a> or <a href=\"\/\/pdf1.alldatasheet.net\/datasheet-pdf\/view\/72882\/MAXIM\/MAX1634EAI.html\" target=\"_blank\" rel=\"noopener noreferrer\">Maxim1634EAI<\/a> that would be a failure if there&#8217;s a surge in power.<br \/>\nSince there&#8217;s NO video display <a href=\"https:\/\/www.digchip.com\/datasheets\/parts\/datasheet\/321\/DS90CR285MTD.php\" target=\"_blank\" rel=\"noopener noreferrer\">DS90CR285MTD &#8211; LVDS controller<\/a> must not have power &#8211;<\/p>\n<div class=\"igallery\">\n<p style=\"text-align: center;\"><a title=\"Head Unit 4E0 035 729 Circuit Board\" href=\"\/\/www.dognmonkey.com\/audi\/wp-content\/uploads\/sm_hu22.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-thumbnail wp-image-2819\" src=\"\/\/www.dognmonkey.com\/audi\/wp-content\/uploads\/sm_hu22-200x112.jpg\" alt=\"Head Unit 4E0 035 729 Circuit Board\" width=\"200\" height=\"112\" srcset=\"https:\/\/www.dognmonkey.com\/audi\/wp-content\/uploads\/sm_hu22-200x112.jpg 200w, https:\/\/www.dognmonkey.com\/audi\/wp-content\/uploads\/sm_hu22-300x168.jpg 300w, https:\/\/www.dognmonkey.com\/audi\/wp-content\/uploads\/sm_hu22.jpg 800w\" sizes=\"auto, (max-width: 200px) 100vw, 200px\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a title=\"MMI 2G Diagram\" href=\"\/\/www.dognmonkey.com\/audi\/wp-content\/uploads\/mmi2g_diagram.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-thumbnail wp-image-2817\" src=\"\/\/www.dognmonkey.com\/audi\/wp-content\/uploads\/mmi2g_diagram-200x112.jpg\" alt=\"MMI 2G Diagram\" width=\"200\" height=\"112\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a title=\"VCDS Output Results on an Open MOST bus AMI circuit\" href=\"\/\/www.dognmonkey.com\/audi\/wp-content\/uploads\/optical_open.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-thumbnail wp-image-2813\" src=\"\/\/www.dognmonkey.com\/audi\/wp-content\/uploads\/optical_open-200x112.png\" alt=\"VCDS Output Results on an Open MOST bus AMI circuit\" width=\"200\" height=\"112\" \/><\/a>\u00a0 \u00a0 \u00a0<a title=\"VCDS output results on working MOST bus\" href=\"\/\/www.dognmonkey.com\/audi\/wp-content\/uploads\/optical_fixed.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-thumbnail wp-image-2815\" src=\"\/\/www.dognmonkey.com\/audi\/wp-content\/uploads\/optical_fixed-200x112.png\" alt=\"VCDS output results on working MOST bus\" width=\"200\" height=\"112\" \/><\/a><\/p>\n<\/div>\n<p style=\"text-align: center;\"><div class=\"youtube-player\" data-id=\"nt5k40hIb58\"><\/div><\/p>\n<ul class=\"lcp_catlist\" id=\"lcp_instance_0\"><\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Audi MMI 2G &amp; 3G MOST bus is very simple but yet very hard to\u00a0diagnose which components connected to the bus is faulty due to the serial optical connections. If the system is not\u00a0thoroughly tested and diagnosed, many good parts can be replaced in the process.\u00a0This is a simple test just show that an open <a href=\"https:\/\/www.dognmonkey.com\/audi\/an-open-circuit-test-on-mmi-2g-most-bus-and-vcds-read-out-results.html\" class=\"more-link\">&#8230;<\/a><\/p>\n","protected":false},"author":2,"featured_media":2817,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[218,19,520],"tags":[226,556,248,381,856,583,857,139,230],"class_list":["post-2812","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-audi-mmi-multi-media-interface","category-vag-com","category-vcds","tag-4e0-035-729-a","tag-a8-d3","tag-mmi-2g","tag-most","tag-open-circuit","tag-optical-bus","tag-optical-loop","tag-q7-2","tag-vcds"],"views":9238,"_links":{"self":[{"href":"https:\/\/www.dognmonkey.com\/audi\/wp-json\/wp\/v2\/posts\/2812","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.dognmonkey.com\/audi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.dognmonkey.com\/audi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.dognmonkey.com\/audi\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.dognmonkey.com\/audi\/wp-json\/wp\/v2\/comments?post=2812"}],"version-history":[{"count":3,"href":"https:\/\/www.dognmonkey.com\/audi\/wp-json\/wp\/v2\/posts\/2812\/revisions"}],"predecessor-version":[{"id":5479,"href":"https:\/\/www.dognmonkey.com\/audi\/wp-json\/wp\/v2\/posts\/2812\/revisions\/5479"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.dognmonkey.com\/audi\/wp-json\/wp\/v2\/media\/2817"}],"wp:attachment":[{"href":"https:\/\/www.dognmonkey.com\/audi\/wp-json\/wp\/v2\/media?parent=2812"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.dognmonkey.com\/audi\/wp-json\/wp\/v2\/categories?post=2812"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.dognmonkey.com\/audi\/wp-json\/wp\/v2\/tags?post=2812"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}