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Electronics => Repair => Topic started by: diewindowsdie on October 21, 2015, 06:26:16 pm

Title: HP 34401A, Error 602
Post by: diewindowsdie on October 21, 2015, 06:26:16 pm

Hi guys!

Received my HP 34401A from ebay seller today. Full self-test reports error 602, which is RAM read/write error. I have also checked main functions - DC voltage/current, AC voltage, continuity test, frequency, resistance - and everything seems to work fine (except for out of calibration maybe, can't check that). So my question is - why a multimeter actually needs a RAM? It is only for programming-related stuff? What is the consequences on leaving it as-is in terms of being able to perform basic measurements?

Thanks.

Title: Re: HP 34401A, Error 602
Post by: bitseeker on October 21, 2015, 10:48:22 pm

The logging function likely uses the RAM. Also, any temporary settings would go into RAM. The calibration values would be stored in non-volatile memory, so no worries there.

For basic measurements, you're probably fine. I'm not sure about the math functions, though. Give them a try.

Title: Re: HP 34401A, Error 602
Post by: free_electron on October 22, 2015, 01:13:46 am

the 34401 has like half a megabyte of ram. you have to remeber there are 3 CPU's in that thing ... plus 3 asics plus 2 flash roms plus an eeprom ...

Title: Re: HP 34401A, Error 602
Post by: Ordinaryman1971 on December 18, 2019, 07:40:02 pm

I wonder if anybody solved one of those errors?

Title: Re: HP 34401A, Error 602
Post by: Ordinaryman1971 on December 26, 2019, 04:49:25 pm

To answer my own question the solution is to change the RAM. It's 256K, 32k x 8.