Massive Static Crunch?

[plresults]

Weird issue - New-to-me Yamaha PF-800, have played 21 LP sides with zero issues. Belt is a little worn and needs replacing. TT needs some manual help to get up to speed at start. It has an old Shure DS HE cart on it. A minute or two after finished and auto shut off, it made the most horrible crackle static, twice. So bad I thought it could damage speakers. Tried CD player on same rig, no issue. Turned on turntable but did not play - no crackle. I did start recently using Blu-tak to clean stylus. Cantilever appears (unaided) ok. Any ideas before I try to replicate?

 

[spicer]

Weird issue - New-to-me Yamaha PF-800, have played 21 LP sides with zero issues. Belt is a little worn and needs replacing. TT needs some manual help to get up to speed at start. It has an old Shure DS HE cart on it. A minute or two after finished and auto shut off, it made the most horrible crackle static, twice. So bad I thought it could damage speakers. Tried CD player on same rig, no issue. Turned on turntable but did not play - no crackle. I did start recently using Blu-tak to clean stylus. Cantilever appears (unaided) ok. Any ideas before I try to replicate?

I don't have the diagram but I'm wondering how it turns on and off... a microswitch, something like that. If so it might be going bad, 'arcing' a bit before completing it's function.

 

[MisterDK]

Could it be that the air is dry and you just have lots of static around? Happens here all the time.
When I notice the static, I water all the plants in the house and fill the pot on my fireplace insert with water. Seems to help.

Another thought.. Does your turntable have a good ground going to it?

 

[jd-audio]

I don't have the diagram but I'm wondering how it turns on and off... a microswitch, something like that. If so it might be going bad, 'arcing' a bit before completing it's function.

There actually is relatively a lot of electronics inside, a pcb with some transistors, and ic and a selenoid on the arm base. Probably best to let an experienced tech look at it.

Have fun
-John-

 

[plresults]

Could it be that the air is dry and you just have lots of static around? Happens here all the time.
When I notice the static, I water all the plants in the house and fill the pot on my fireplace insert with water. Seems to help.

Another thought.. Does your turntable have a good ground going to it?

Hi: Thanks for your thoughts. I believe that ground is okay on the amp. I do get a hum with another table on that amp, but I assumed it was the other TT doing that, and not the amp (a Sansui AU 717, which has been fully rehabbed).

 

[ripblade]

Whatever it is that caused the crackle, it manifested itself through the audio circuit, which shouldn't happen. I would check to make sure the TT chassis is properly and independently grounded to the preamp, and not through the audio cables.

 

[plresults]

While quite fearful, I ran it again three times after re-attaching the TT ground wire to the Sansui AU717. No crunch during at end of play when autolift engages. Oddly - it didn't appear that the ground wire was misattached in any way. When the crunch came, it was several minutes AFTER play.

 

[Bob in WI]

While quite fearful, I ran it again three times after re-attaching the TT ground wire to the Sansui AU717. No crunch during at end of play when autolift engages. Oddly - it didn't appear that the ground wire was misattached in any way. When the crunch came, it was several minutes AFTER play.

after play so you would think the TT cycle was complete. Doesn't make sense to me but I'm no tech.
Nice deck - you'll get it sorted out.

 

[Mr Boochie]

Clean and tighten all interconnect grounding collars. Deoxit all connections. You may to clean and use Dexoit on that micro-switch.

 

[plresults]

Clean and tighten all interconnect grounding collars. Deoxit all connections. You may to clean and use Dexoit on that micro-switch.

Hi Mr. B from Mars: Greetings from suburban Milwaukee! What is the microswitch to which you refer? Is that the switch that lifts the arm and turns off the TT?