{"id":36,"date":"2011-08-30T13:24:33","date_gmt":"2011-08-30T13:24:33","guid":{"rendered":"https:\/\/pinball.teta.be\/?p=36"},"modified":"2011-10-20T19:02:13","modified_gmt":"2011-10-20T17:02:13","slug":"the-electronics","status":"publish","type":"post","link":"https:\/\/pinball.teta.be\/?p=36","title":{"rendered":"The electronics"},"content":{"rendered":"

Before switching on the pinball machine for the first time, I checked the input voltage settings on the main transformer and the fuses there and I checked the fuses on the power supply board. I needed to replace one fuse, it looked good, but when I measured it with my multimeter it failed the test.<\/p>\n

Then I finally switched the machine on. Nothing happened. Then I plugged in the power cord and tried again… Lights came on, displays flickered at random and then went out. That was it.<\/p>\n

Clearly things are not working as they should, time for some troubleshooting.<\/p>\n

So where to start? With the power supply ofcourse!<\/p>\n

The first thing I noticed was no -5VDC due to a defective 7905. Off to the store I went and now the power supply has a brand new 7905.<\/p>\n

\"New<\/a>

The new 7905<\/p><\/div>\n

Unfortunately after fixing the -5VDC I tested again and the 170VDC was gone. After a few measurements I noticed that TR3 (2N3440) had come loose from the PCB. Shabby soldering? That knocked out R6 (47 Ohm 3W) as well. Off to the shop I went again. I had to use a 5W resistor, but that’s not a problem.<\/p>\n

\"R6\"<\/a>

The new R6 (47 Ohm 5W)<\/p><\/div>\n

\"TR3\"<\/a>

The new TR3 (2N3440)<\/p><\/div>\n

I reconnected the power supply board into the pinball machine and tried again. Except for a pop from the loudspeaker when switching on nothing changed. I disconnected everything except the sound board and after pressing the test button on it, the LED blinked 5 times and the pinball machine started talking to me \ud83d\ude42<\/p>\n

The Sound Test<\/a> video, best viewed with VLC media player (see my links section).<\/p>\n

I disconnected the sound board and reattached the CPU board. It would not boot. After some reading on zaccaria-pinball.com (see my links section) I checked the Power Fail signal coming from the power supply board and yes, it was the wrong signal \ud83d\ude41<\/p>\n

So I did what all good technicians do and disconnected the lead from the connector. Problem solved. I promise to get the power fail circuit fixed later on. I promise!<\/p>\n

\"The<\/a>

I promise to check this power fail circuit later on...<\/p><\/div>\n

\"The<\/a>

The power fail workaround<\/p><\/div>\n

After retrying to boot the CPU, it actually did… sort of. I starts booting but then keeps hanging somewhere. When measuring the test points, I don’t get the pulse signal on TP6. Further testing and digging in the schematics is necessary. To be continued…<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

Before switching on the pinball machine for the first time, I checked the input voltage settings on the main transformer and the fuses there and I checked the fuses on the power supply board. I needed to replace one fuse, it looked good, but when I measured it with my multimeter it failed the test. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,46],"tags":[15,12,8,13,14,24],"class_list":["post-36","post","type-post","status-publish","format-standard","hentry","category-electronics","category-pinball-champ","tag-cpu","tag-electronics-2","tag-pinball-2","tag-power-supply","tag-sound","tag-zaccaria"],"_links":{"self":[{"href":"https:\/\/pinball.teta.be\/index.php?rest_route=\/wp\/v2\/posts\/36","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pinball.teta.be\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pinball.teta.be\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pinball.teta.be\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pinball.teta.be\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=36"}],"version-history":[{"count":8,"href":"https:\/\/pinball.teta.be\/index.php?rest_route=\/wp\/v2\/posts\/36\/revisions"}],"predecessor-version":[{"id":231,"href":"https:\/\/pinball.teta.be\/index.php?rest_route=\/wp\/v2\/posts\/36\/revisions\/231"}],"wp:attachment":[{"href":"https:\/\/pinball.teta.be\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=36"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pinball.teta.be\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=36"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pinball.teta.be\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=36"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}