3458A: continuous beep during power on after power loss - Page 1
Forum section: electronics / general

author: niner_007
author_rank: Frequent Contributor
timestamp: October 13, 2020, 10:04:35 pm
content: Sometimes, during a power condition I noticed that the 3458A restarts with the display off but continuously beeping and no responsiveness, to fix, it is required to power off for a few seconds and then start again. Anyone knows where this is documented?

author: IanJ
author_rank: Unknown
timestamp: October 15, 2020, 09:43:08 am
content: Hi,Are you saying you get a momentary (less than 2 or 3 of seconds) of power loss before it comes back on again and thus the 3458A re-boots?Thats not great for any electronic test instruments and not surprising it can't restart properly. It can put strain on the power supply.However, if you are getting a power loss for 4 seconds or more then then it should re-boot just fine......and in this case I'd check the power supply outputs, it could be that a rail or two isn't starting properly when there is residual charge in the caps.Ian.

author: Dr. Frank
author_rank: Super Contributor
timestamp: October 15, 2020, 10:04:05 am
content: Hello,I've never heard about this behavior before, nor have I encountered such on my own 3458A, especially not when I turn it off regularly, and switch it on again a short time later.It's definitely no regular state of the instrument, and definitely nowhere documented.You probably want to indicate, that you have frequent mains black- or brown-outs?So, how long do these interruptions last, i.e. minutes, seconds, or are these just brief break-downs of the mains voltage?I can only imagine, that latter events only may cause this behavior.The calibration constants should be safe.Frank

author: niner_007
author_rank: Frequent Contributor
timestamp: October 16, 2020, 06:29:05 am
content: No brownouts or blackouts, I was testing powering my lab by an inverter, as part of the test I noticed this behavior on one of my 3458A, the other did not exhibit this behavior. Maybe it's a feature of the new digital board. The blackout was maybe 500ms-1s.

author: acts238willy
author_rank: Regular Contributor
timestamp: October 16, 2020, 06:44:50 am
content: Is it a pure sine wave inverter?My APC sine wave UPSes never cause a problem for my 3458s....

author: niner_007
author_rank: Frequent Contributor
timestamp: October 16, 2020, 08:56:01 am
content: Yes, pure sine wave, it's a Meanwell TS-200. I had deliberately caused the blackout/brownout as part of testing the inverter and deadtime.

author: Villain
author_rank: Regular Contributor
timestamp: October 17, 2020, 09:50:44 am
content: I can not imagine it being a new feature.

author: martinr33
author_rank: Frequent Contributor
timestamp: October 17, 2020, 11:16:37 am
content: I would be looking at the power supply caps.

author: eplpwr
author_rank: Regular Contributor
timestamp: October 17, 2020, 07:18:15 pm
content: I had my 3458A in continuous beep once. My digital board did not have the extended memory, rather a crippled 03458-88807 chip that disables the 001 memory. Some googling got me the information that replacing the PAL chip with 03458-88810 would do the trick. Bought the chip and replaced the original PAL chip. Power on = constant beep. After putting back the original chip, nervously, the meter started again.Afterwards, I understoid that -88807 chip is supposed to be replaced by -88808 to get extra memory, and those that have -88809 chip for STD/crippled memory can be upgraded by -88810. It ended with an upgrade kit @$800+ for me to get the right chip.Bottom line - a constant beep is a sign of severe malfunction, in my case the processor board not working.

author: martinr33
author_rank: Frequent Contributor
timestamp: October 18, 2020, 11:57:45 pm
content: (off topic but related to the PAL replacement comment)Yes - there are two versions of that "short" CPU board. The first one uses the -88807/8 PALS, and the second one the -88809/10 version. I've never figured out why they are not interchangeable.Looks like -88810 is still available for $38.07. The chip is an 8-pin configuration memory for the FPGA, not a PAL device.I don't know if the device is readable, and therefore clonable from another machine.07/08 are not orderable. 09/10 are - as of this date.

author: niner_007
author_rank: Frequent Contributor
timestamp: October 19, 2020, 05:59:44 am
content: I've had this repaired recently by Keysight so it is still under warranty, I can ask them to look at it and do the necessary replacements

author: martinr33
author_rank: Frequent Contributor
timestamp: October 22, 2020, 12:38:47 am
content: You'll need to make sure that you can reproduce the problem with a wall socket.