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HT750 On/Off problems
Posted: Tue Jan 17, 2012 7:14 am
by kkarm
I have an HT750 that turns on by just putting on the battery and the on/off switch is off but then I cant turn it off with the switch. the switch is good I have reflowed several components to no availe. any help would be appreciated.
Re: HT750 On/Off problems
Posted: Tue Jan 17, 2012 9:38 am
by CircleBat
the switch is defective.. common problem.. if not, the zener diode is shot..
CircleBat
Re: HT750 On/Off problems
Posted: Tue Jan 17, 2012 3:40 pm
by ferrisbuehler
Interesting.... Which Zener is the usual culprate? I have one here that randomly makes noise, pops etc. while turned off-out of the charger. I remember a zener problem wayyyy back but forgot what the fix is.. Any ideas??
Thanks
Re: HT750 On/Off problems
Posted: Wed Jan 18, 2012 7:11 am
by kkarm
Which zener VR439 or VR501
Re: HT750 On/Off problems
Posted: Wed Jan 18, 2012 11:34 pm
by CircleBat
vr501.. common problem in earlier versions
Circlebat
Re: HT750 On/Off problems
Posted: Thu Jan 19, 2012 1:25 pm
by ferrisbuehler
Thanks muchly!!
Re: HT750 On/Off problems
Posted: Fri Jan 27, 2012 10:34 am
by kkarm
Tried the vr501 zener and still have same problem...... comes on with on off in off position and just put on battery. I have no idea.
Re: HT750 On/Off problems
Posted: Sat Jan 28, 2012 3:59 am
by CircleBat
did you replace the volume pot?
Re: HT750 On/Off problems
Posted: Sat Jan 28, 2012 9:05 pm
by 35echo
kkarm,
More than likely Q400 which is the main B+ switch is shorted.
Regards,
Allen