Beomaster 1900 IL1 Testing

7 replies
TR
Offline
traverso
Bronze
Posted October 26, 2023 at 10:10 GMT
#1642821
Hello,

The input signal is not reaching the balance potentiometer

It is stopped at Test Point 200 or 300 and not going through R226 and R326

I suspect IL 1 to be faulty and would like to know how to test the lamps inside

Thanks a lot for the feedback

 

Alain
TR
Offline
traverso
Bronze
Posted October 26, 2023 at 10:34 GMT
#1659603
I could measure the IL1 lamp resistance between emitter TR24 and 15 V and found 17,7 Ohms is this value OK?

If yes the problem is elsewhere, any thought?
SO
Offline
sonavor
Bronze
Posted October 26, 2023 at 16:02 GMT
#1659612
hi traverso,

IL1 or the LDR devices inside the volume control (8002293) could be the problem.
Take the cover off the volume control and see if the lamp illuminates.

Did you also check the contacts on the Balance control slider?

-sonavor
TR
Offline
traverso
Bronze
Posted October 26, 2023 at 18:41 GMT
#1659622
Hello,

Thank you for the help

I used a one Khz tone generator connected to the recorder input  and the signal arriving at the balance control is very low

I will open the LDR by tomorrow for checking

Alain
TR
Offline
traverso
Bronze
Posted October 27, 2023 at 09:08 GMT
#1659638
The lamp is probably OK as measured 17 Ohms

However I have ordered a repair kit for this LDR

By the way, is there a trick to remove the cover of this LDR? Is it glued or just clipped?
TR
Offline
traverso
Bronze
Posted October 27, 2023 at 10:17 GMT
Edited October 27, 2023 at 10:17 GMT
#1659639
Actually I unsoldered the LDR, more easy to open it

The metal cover is glued to the black plastic support see attached picture

The lamp is dead

TR
Offline
traverso
Bronze
Posted November 6, 2023 at 18:00 GMT
#1659948
The LDR components were the culprits

I used a repair kit from Beoparts and put back the LDR in the 1900, everything is fine

The 1900 is back to life and sing again

Thank you Sonavor
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