Sony HCD-EH45DAB - No sound on radio.

[Turnip]

Hi folks,

Have one where the CD plays normally, but FM and DAB tune correctly but with no sound at all. Had a look about for a manual, no dice. Gather the problem isn't unknown, wonder if anyone knows ? - Thanks - Chris.

[astracat]

hi turnip
q704 is a reset transister quickly short emitter and collecter to reset may need to retune after or a cold reset will erase its memory
circuit on on http//sevicemanuals.us
regards
astracat

[Turnip]

Thanks 'Cat'

Will check out Q704 and try get schematic as you advise - Many thanks - Chris.

[jordan]

https://elektrotanya.com/sony_hcd-eh45dab_ver.1.0.pdf/download.html

[Turnip]

Thanks Jordan,

Notice Q704(Sony RT1N441C-TP-1) don't seem gettable for a decent price, but basic RT1N441C cheap. Notice Amazon did the originals a while ago, but now discontinued. Wonder if there's any difference ?  guess will soon find out - Chris.

[astracat]

hi turnip
remove q704 apply power then intermitantly short its collecter to ground to reset system control ic ,if that doesnt bring to life the radio side then q704 probably ok, if every thing works ok then replace q704 its a darlington type transistor. could also try reflow on x102 also these required to to be correct
i/c601,pin 5 1.2v,q191,q194,q196 q198 to give out 3.3v all voltages when on radio function
good luck
regards
astracat

[Turnip]

Thanks 'Cat'

Note Q704 is a switching npn transistor with resistors base and base to emitter - Not a darlington dual transistor.

Replaced Q704 but exactly the same.

Tend to feel I'm out of luck, don't care try reflow chips as they never get warm enough to be an issue.

Guess can't win 'em all - Many thanks though - Chris.