I accidently shorted the speaker output wires on my Beomaster 1900. This killed all output from the left channel.

Reply

quattttro Posted: Mon, Jul 12 2021 1:32 PM

rated by 0 users

Right channel still works. What component (s) would most likely die in this scenario? Where would you check first?

I've checked the Darlingtons transistors with my component tester, and they seemed to check OK, and I notice nothing burned or blown caps. Checked various resistors in the left channel power amp circuit, all are fine.

Here she is, before the incident:

Reply

Dillen replied on Mon, Jul 12 2021 9:13 PM

rated by 0 users

Replace
IC200 (*)
IC201
TR216
TR217
TR214
TR215
TR213
TR212
Check all other components downstream from TR212, including R242 and R245.
Also replace the idle current trimmer, and readjust to the setting stated in the servicemanual.

Don't buy semiconductors from Asia. They will almost certainly be fakes.

Martin

*EDITED

Reply

quattttro replied on Mon, Jul 12 2021 11:30 PM

rated by 0 users

Will do, thanks. Which one is IC100 (did you mean IC200?)?

Reply

Dillen replied on Tue, Jul 13 2021 7:05 AM

rated by 0 users

quattttro:

Will do, thanks. Which one is IC100 (did you mean IC200?)?

Yes. Now corrected.
It's always a good idea to replace output stage transistors in pairs (or quads where applicable).
If one has shorted, the other one will have seen a hefty overload.

Martin