Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Equipment Usage, Soldering, Techniques, and Reviews
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 10-26-2011, 09:05 AM   #21
Bob Parker
Technician
 
Bob Parker's Avatar
 
Join Date: Feb 2007
City & State: Werris Creek NSW
My Country: Australia
Line Voltage: 240V 50Hz
I'm a: Professional Tech
Posts: 166
Default Re: Scope probe ground clip sparking on chassis

I'm not going to follow this thread any more, while I still have some hair.

Just be very careful where mains voltages are concerned because the old saying is very true: "A little knowledge is a dangerous thing."
Bob Parker is offline   Reply With Quote
Old 11-26-2011, 09:27 PM   #22
Toasty
Badcaps Veteran
 
Toasty's Avatar
 
Join Date: Jul 2007
City & State: East Coast, USA
Line Voltage: 220-221
I'm a: Professional Tech
Posts: 4,145
Default Re: Scope probe ground clip sparking on chassis

Was this ever resolved?

__________________
veritas odium parit
Toasty is offline   Reply With Quote
Old 11-26-2011, 09:36 PM   #23
Agent24
I see dead caps
 
Agent24's Avatar
 
Join Date: Oct 2007
City & State: Hiding inside a plated-through hole
My Country: New Zealand
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 4,600
Default Re: Scope probe ground clip sparking on chassis

Gave up on it for the time being. I think the tuner is pretty screwed anyway. Even if it's something simple like corrupt firmware I don't know where I'd get a new copy.

Might give it some more time.. sometime... if I can be bothered.
Agent24 is offline   Reply With Quote
Old 12-13-2011, 03:37 AM   #24
riotpack
Member
 
Join Date: Jul 2008
City & State: Toowoomba/Rockhampton
Posts: 28
Default Re: Scope probe ground clip sparking on chassis

http://www.questronix.com.au/info/info_tingles.htm

Read that.
__________________
Thats not a Fuhjyyu I used in your antec PSU its a HITACHI!! rofl lol lmao funni gui!
riotpack is offline   Reply With Quote
Old 04-22-2013, 03:08 AM   #25
Dranoweb
New Member
 
Join Date: Apr 2013
City & State: Victoria
My Country: Australia
I'm a: Knowledge Seeker
Posts: 1
Default Re: Scope probe ground clip sparking on chassis

I apologize for digging up a really old post
I would also like to say thanks for the manual - I just inherited a q1280 myself.

just wondering what frequency probe you went with.

I had high hopes of using this at 470mhz, but looking at the 100khz on the front, i think it's just going to do for my switch mode testing etc.

again sorry for the old post revival - but info on old stuff, is usually in old posts - and indexed on google.
Dranoweb is offline   Reply With Quote
Old 04-22-2013, 07:12 AM   #26
japlytic
Badcaps Veteran
 
japlytic's Avatar
 
Join Date: Oct 2005
City & State: Rockhampton, Queensland, Australia
My Country: Australia
Line Voltage: 240VAC 50Hz
I'm a: Hobbyist
Posts: 1,958
Default Re: Scope probe ground clip sparking on chassis

Quote:
Originally Posted by Toasty View Post
From Kemet.com:
X capacitors are across the line. { Think X = cross }
If they short-circuit, the risk is fire.
Many X-class capacitors are flameproof, a condition of agency approval.

Quote:
Originally Posted by Toasty View Post
Y capacitors are from line to chassis. { Think Y = upper points are power lines, lower is ground. }
If they short-circuit, the risk is a shock to the user. => as is your case
Y-class units are designed not to fail, but when the do fail, they fail safely (go open circuit); again, a condition of agency approval.

---

Remember capacitors are reactive components as well (their reactance is dependent on frequency), which means Y-class capacitors can transfer minute amounts of current between the line and isolated chassis, but this is not enough to become dangerous.
__________________
My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.
japlytic is offline   Reply With Quote
Old 04-22-2013, 11:15 PM   #27
Agent24
I see dead caps
 
Agent24's Avatar
 
Join Date: Oct 2007
City & State: Hiding inside a plated-through hole
My Country: New Zealand
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 4,600
Default Re: Scope probe ground clip sparking on chassis

Quote:
Originally Posted by Dranoweb View Post
just wondering what frequency probe you went with.

I had high hopes of using this at 470mhz, but looking at the 100khz on the front, i think it's just going to do for my switch mode testing etc.
I got a cheap 50 MHz probe on eBay from some Chinese seller. Probably doesn't even work up to 50 MHz but I doubt it matters since that scope is only good for 5 MHz anyway.

The most limiting issue with this Q1280 is that the controls are unmarked and uncalibrated. You have no way of knowing voltage and frequency accurately unless you compare to a known signal.

Despite that though, it's still useful, and much better than no scope at all. But if you can afford it you should probably get something better.
__________________
"Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
-David VanHorn
Agent24 is offline   Reply With Quote
Old 04-24-2013, 10:14 PM   #28
redwire
Badcaps Veteran
 
Join Date: Dec 2010
City & State: Alberta
My Country: Canada
Posts: 1,312
Default Re: Scope probe ground clip sparking on chassis

I've repaired a few scopes that got damaged when a noob connected the probe to a mains-referenced circuit. Like a TV or SMPS, the -ve DC rail is live and big spark when you connect the scope probe ground there.
It melts a (chassis/earth) ground trace in the scope and it becomes a floater. The X-cap then bites you. Hard to find the pcb break, but most scopes have their bnc gnd to the power cord, if you check with an ohmmeter. They're not designed for a 15A fault there.
redwire is offline   Reply With Quote
Old 04-24-2013, 10:16 PM   #29
redwire
Badcaps Veteran
 
Join Date: Dec 2010
City & State: Alberta
My Country: Canada
Posts: 1,312
Default Re: Scope probe ground clip sparking on chassis

Oops I meant the Y-cap bites you, its leakage current can make small sparks or give you a jolt because the scope lost its ground trace.
redwire is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums 2003 - 2019
Powered by vBulletin ®
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 04:00 PM.
Did you find this forum helpful?