HT750 On/Off problems

[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.

[CircleBat]

the switch is defective.. common problem.. if not, the zener diode is shot..

CircleBat

[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

[kkarm]

Which zener VR439 or VR501

[CircleBat]

vr501.. common problem in earlier versions

Circlebat

[ferrisbuehler]

Thanks muchly!!

[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.

[CircleBat]

did you replace the volume pot?

[35echo]

kkarm,

More than likely Q400 which is the main B+ switch is shorted.

Regards,

Allen