68kMLA Classic Interface
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| LaserwriterII NTX - fixing the AC Power block | |
| Posted by: Juror22 on 2014-12-02 21:56:53 I have a couple of Laserwriters that I am working on and troubleshooting led me to the issue of a triac at q101 on the AC Powerblock (just under the fan). Anyway - I have no idea how to uncover what to get for a replacement, here are the specs that I know: 1) Its a Mits with the following markings BCR8DM 12L 87 2) my multimeter reports it as a PNP, CEB (no other value) 3) Here is a marginal picture of it, without the heatsink  Any suggestions for a replacement, or how to go about finding one of these - I have tried the obvious searches, but the closest I got were some partial matches on the numbers, no solid replacement. | |
| Posted by: Elfen on 2014-12-02 22:55:39 As far as I remember, a Triac is a pair of transistors tied together serially. The 12L 87, I believe is a Date Code. Searching the Internet, I found a pin out: http://www.pinout.net/element_browse.php?conid=40642 Specs (in .pdf): http://www.alldatasheet.com/view.jsp?Searchword=BCR8DM And it looks like it is no longer made, but there is a equivalent: NTE5638 TRIAC-400VRM 8A TO-220 http://www.weisd.com/test/GenericParts_WEISD_view.php?editid1=BCR8DM-8 I searched Newark.com following a false lead, some other forum said they had them, they don't but thy do have equivalents: http://www.newark.com/webapp/wcs/stores/servlet/Search?catalogId=15003&langId=-1&storeId=10194&categoryId=800000005452&st=triac%20BCR8DM&pageSize=25&showResults=true&pf=810021709,810050159,810087357,811880813,811880814 DigiKey, Mouser, others should have equivalents as well. | |
| Posted by: techknight on 2014-12-03 05:16:45 Triacs usually don't go bad unless they're shorted | |
| Posted by: Juror22 on 2014-12-04 19:07:26 Thanks for the responses. I'll let you know how it goes. | |
| Posted by: oldappleguy on 2014-12-10 20:31:51 I have a couple of lw ll that I am going to recycle. I can send you a power supply from one if you want | |
| Posted by: Juror22 on 2014-12-17 20:30:19 That would be very helpful - pm sent. Thanks oldappleguy 🙂 | |
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