Blown Rigol RP3300A Probe  - Page 1
Forum section: electronics / testgear

author: simmiv
author_rank: Contributor
timestamp: May 07, 2016, 07:37:35 am
content: I had the misfortune to blow one of the Rigol RP3300A passive probe.Thankfully the Rigol Oscilloscope is fine.I saw in another post that the resistance measurement from the tip of the probe to the cable in the housing (where the compensation adjustment cap is) should be 9 Mohm.. In my case it was open circuit! I decided to take it apart with a small grinding wheel, to see what had happened inside the probe tip!First the sheeting and the cable removed.. Note how the cable has a pin which is soldered to the coax wire and then it plugs into a female inside the metal probe..The plastic taken off the probe tip..The metal probe tip sliced apart.On the left you can see where the pin from the coax cable attaches to a female to female connector.. The right one has a male on the left and at the right was the probe tip, which broke off..You can see the resistors and capacitors through the transparent shielding of the probe tip..The right most SMD (Resistor?) blown away..The SMD has mostly disappeared!! No wonder there was open circuit..Now I have to get myself a new one..

author: tautech
author_rank: Super Contributor
timestamp: May 07, 2016, 08:43:15 am
content: Quote from: simmiv on May 07, 2016, 07:37:35 amYou don't explain how.Overvoltage?Exceeding voltage/frequency derating curve?Others can learn from your experience...... we hope you have.

author: simmiv
author_rank: Contributor
timestamp: May 07, 2016, 08:50:28 am
content: I was poking around a switched mode power supply which seemed to be dead!.. I touched the probe tip on the input of the primary transformer. It had about 330v DC on it, so game over! I don't have a high voltage probe, so the lesson is to be more careful around switch mode power supplies..

author: tautech
author_rank: Super Contributor
timestamp: May 07, 2016, 10:06:50 am
content: Quote from: simmiv on May 07, 2016, 08:50:28 am1:1 probe setting ?

author: simmiv
author_rank: Contributor
timestamp: May 07, 2016, 11:10:16 am
content: I'm pretty sure it was 1:10 setting.. There was the dreaded sound when you know you did the wrong thing i.e. like a spark or a short. It tripped my earth leakage fuse I have for my workbench.Simmi

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 07, 2016, 01:28:58 pm
content: Quote from: tautech on May 07, 2016, 10:06:50 ameven at 1:1, the probe and the scope should not be damaged. blowing probe with 330V is a miracle... what i suspect is, the OP shorted the smps circuit sending it to its self destruction, the probe is just another collateral damage.

author: hooverphonique
author_rank: Contributor
timestamp: November 23, 2016, 03:10:23 pm
content: Was going to use my second RP3300A today to measure RS485 differential. Probe seems to behave weirdly.. switching probes/channels around reveals the proble outputs nothing..Now, measurering the resistance of the functioning probe gives open load at the probe end when not connected to oscilloscope, the seemingly dead one measures 9Mohm, which they both measure at the scope end. It seems it's shorted then (coax damaged?), or could this be the result of an overload?Cheers!

author: wraper
author_rank: Unknown
timestamp: November 23, 2016, 03:45:07 pm
content: Quote from: hooverphonique on November 23, 2016, 03:10:23 pmThose probes are a piece of shit, Especially older ones. Disassemble the part with BNC connector and check if central conductor from the coax isn't touching the shell around it.

author: wraper
author_rank: Unknown
timestamp: November 23, 2016, 03:49:29 pm
content: Quote from: tautech on May 07, 2016, 10:06:50 amRP3300A is 1:10 only.Quote from: simmiv on May 07, 2016, 11:10:16 amI guess you are talking about scope setting which does not matter as it is purely what numbers are shown on the screen.

author: hooverphonique
author_rank: Contributor
timestamp: November 23, 2016, 05:43:21 pm
content: Quote from: wraper on November 23, 2016, 03:45:07 pmLOL! Took the tinny shell of the connector end and lo and behold, the center coax lead was so long it came into contact with the small torx screw that holds the pcb in place..I was wondering.. Would the Testec TT-HF212 be a worthy cheapish replacement probe? (scope is hacked to 300MHz so may as well get probes with larger BW).Cheers!

author: mk_
author_rank: Regular Contributor
timestamp: November 23, 2016, 09:51:57 pm
content: Quote from: hooverphonique on November 23, 2016, 05:43:21 pmTestec is usuialy ok. But: take care for the voltage-derating at high frequency if you are usinge the probes not at low voltages only.Michael