Philips radio BCA628A (Algemeen)

door Pandu Rajan , 27.04.2022, 09:24 (729 dagen geleden) @ Ouwe Schipper

Dear MR. Schipper

You were correct in suspecting the O/P valve. The no load filament voltage was 7.35V. With all the valves in place this was dropping to 4.68V. I removed the EL41 valve and measured the total D.C. current and it was 19ma. With the defective EL41 this was coming to 27ma. In the schematic for the BCA628A The various currents are given and the total current comes to 60ma. So the current with the old EL41 valve was very less and this was the reason for the high D.C. voltage at C1 and C2. I replaced the valve EL41 and the various voltages measured are as follows:
1. Incoming voltage -- 223V a.c.
2. Secondary voltage -- 272-0-272 V a.c.
3. filament voltage (4V)-- 4.34V a.c.
4. Filament Voltage (6.3V)-- 6.34V a.c.
5. D.C. voltage at C1 - 283V
6. D.C. voltage at C2 - 258V
7. The total d.c. current - 58.4ma.

But still the voltage at C1 and C2 is high by 23/28V
Kindly advise?

Regards
P.Rajan