Hi all,
I have here a Studer euro-card board 1.915.301.00. One of these board is faulty. Schematic is attached.
What i found so far:
Fuse F1 was blown, because C21 was blown and created a short.
Also the IC3 was installed reversed. This could have been done after it stopped working with a quick check. The board worked flawless for many years.
C21, fuse and ic 3 are replaced an ok but it still does not work.
Now the bipolar transistor Q1 (BD517) gets very very hot. Too hot to touch after 2-3 minutes. Also the output transformer gets hot. Hotter than the other cards. I measured all components on board and i find no odd values.
Is this just Q1, BD517 that died or am i missing something here? Any advice and tips what to check?
Thanks for your help and best,
Menno
I have here a Studer euro-card board 1.915.301.00. One of these board is faulty. Schematic is attached.
What i found so far:
Fuse F1 was blown, because C21 was blown and created a short.
Also the IC3 was installed reversed. This could have been done after it stopped working with a quick check. The board worked flawless for many years.
C21, fuse and ic 3 are replaced an ok but it still does not work.
Now the bipolar transistor Q1 (BD517) gets very very hot. Too hot to touch after 2-3 minutes. Also the output transformer gets hot. Hotter than the other cards. I measured all components on board and i find no odd values.
Is this just Q1, BD517 that died or am i missing something here? Any advice and tips what to check?
Thanks for your help and best,
Menno
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