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Old 12-04-2020, 10:10 PM
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Electronic M Electronic M is offline
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 15,457
After going through a proceedure on youtube to fix the capstan and head drum speed issues by replacing the light blue caps on the SS-9 board and adjusting speed pots I ended up breaking the head drum drive circuit trying to puzzle it out.

Earlier today I decided since I had been able to force it to play a tape well and I have a second identical one that it was worth springing for the overpriced blurry Sam's for it.
Several bad NPN transistors on the SS-9 board were the cause of several lines being locked in various undesirable states...Q522 which was causing the low reel motor play voltage temporary fixed things but it relapsed and I ended up adding an 820 ohm in series with the collector to limit the pull down that transistor could achieve.

It works now...now to try and make the other deck work.
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