H
H. R. Bob Hofmann
I have just started to trouble-shoot a 1988 RCA CTC 148/149 chassis,
with the stereo option. I do not have a schematic, but am fairly
experienced and hope to get by on that. I have a good Tektronix
scope, voltmeter, and a signal generator from audio through several
megahertz.
Symptoms are fine sound on the monaural/right channel at low volume,
badly distorted as sound volume is turned up. Clip-leaded another
speaker, same symptoms. I haven't looked (with a scope) at the stereo
RCA plugs on the back of the set to see if there is distortion before
the audio output IC. Can't cross-reference the audio output IC to an
ECG replacement. It is marked NEC Japan, uPC 1335V, 9125B.
Is there an ECG replacement that I have missed in my catalog? Does
this chassis have a history of sound problems, and if so what are the
suspect parts?
Thanks for any suggestions.
H. R.(Bob) Hofmann
with the stereo option. I do not have a schematic, but am fairly
experienced and hope to get by on that. I have a good Tektronix
scope, voltmeter, and a signal generator from audio through several
megahertz.
Symptoms are fine sound on the monaural/right channel at low volume,
badly distorted as sound volume is turned up. Clip-leaded another
speaker, same symptoms. I haven't looked (with a scope) at the stereo
RCA plugs on the back of the set to see if there is distortion before
the audio output IC. Can't cross-reference the audio output IC to an
ECG replacement. It is marked NEC Japan, uPC 1335V, 9125B.
Is there an ECG replacement that I have missed in my catalog? Does
this chassis have a history of sound problems, and if so what are the
suspect parts?
Thanks for any suggestions.
H. R.(Bob) Hofmann
