Video Repair of an Agilent E4418A Power Meter & Power Sensor Tutorial - Page 1
Forum section: electronics / general

author: Hugoneus
author_rank: Frequent Contributor
timestamp: June 06, 2015, 03:49:08 pm
content: <Description coming soon>Watch the video here: [1 Hour & 18 Minutes]http://youtu.be/py06VNvykTkMore videos at The Signal Path:http://www.TheSignalPath.com

author: miguelvp
author_rank: Super Contributor
timestamp: June 06, 2015, 05:48:45 pm
content: Still watching it but the service manual seems to be available on Keysight's website:http://www.keysight.com/en/pd-1000002797%3Aepsg%3Apro-pn-E4418A/epm-series-single-channel-power-meter?cc=US&lc=engClick on document library and it's the last one, you have to provide your email address and name to proceed.No schematic but it does have a block diagram, but since I assume you fixed it then you probably don't need it

author: Hugoneus
author_rank: Frequent Contributor
timestamp: June 06, 2015, 07:41:35 pm
content: Great! Too bad no schematic is available.

author: bson
author_rank: Unknown
timestamp: June 07, 2015, 12:16:06 am
content: Nice!

author: nidlaX
author_rank: Frequent Contributor
timestamp: June 07, 2015, 01:45:12 am
content: Interesting, is SRAM a common point of failure in older equipment?

author: Shock
author_rank: Super Contributor
timestamp: June 07, 2015, 04:49:53 am
content: Another great video, was expecting you to check the backup battery voltage at some point there. Did you have to take any precautions due to the battery while desoldering?Quote from: nidlaX on June 07, 2015, 01:45:12 amNo more than the other dozen or so common issues often found in "death by natural causes".

author: ivaylo
author_rank: Frequent Contributor
timestamp: June 07, 2015, 07:04:21 am
content: Nice, as always... Keep them coming please.

author: bingo600
author_rank: Super Contributor
timestamp: June 07, 2015, 07:47:23 am
content: Quote from: Shock on June 07, 2015, 04:49:53 amI didnthttps://www.eevblog.com/forum/testgear/hp-e4418b-epm-powermeter-battery-change/msg420607/#msg420607Afaik the battery just backs up user settingsI will have to watch this one , thanx SPAny quick hints on the diff of the A & B versions ?/BingoPs: Have a look at this calibrating doc, that i got from a friend of KJDS, when i just got my E4418B, i use it all the timehttps://www.eevblog.com/forum/testgear/hp-e4418b-epm-powermeter-battery-change/?action=dlattach;attach=88275

author: Hugoneus
author_rank: Frequent Contributor
timestamp: June 07, 2015, 11:07:04 pm
content: Excellent!

author: Hugoneus
author_rank: Frequent Contributor
timestamp: June 08, 2015, 02:58:03 pm
content: Quote from: nidlaX on June 07, 2015, 01:45:12 amI also think this is just death due to old age... RIP.

author: MarkL
author_rank: Unknown
timestamp: June 09, 2015, 04:47:18 pm
content: Great video, Shahriar, thanks!Here's something I've been wondering... Why do some sensors that end in the same connector type have a longer bulkhead assembly than others? Your disassembly shows that it's just a coaxial deisgn through the multiple pieces.Is there an RF reason?

author: pigrew
author_rank: Frequent Contributor
timestamp: March 01, 2018, 07:50:58 pm
content: I just bought an EPM-441A (same as the E4418A, I believe, just with a different part number), and the video was helpful in the disassembly. It's nice to see parts taken apart before trying to take them apart myself. The E4418B also seems nearly identical to the E4418A, just with a few extra IO ports on the back.Mine, being an older unit, had the old A.01.10 "DSP firmware". A newer version was required to update the firmware to the newest revision. The upgrade kit has been discontinued, but thankfully I was able to find the new firmware on KO4BB. It's stored on an Intel AM28F512-150JCL flash IC. That flash IC is also discontinued, and there is no modern replacement. I risked by unit by erasing it and reflashing the new firmware (using a TL866). I initially had some trouble reading the existing code. I was getting empty blocks during the reads. After about four tries, the old firmware seemed to have been read successfully. I don't know if the flash was too old and it was having trouble reading it, or if there was an error in the TL866. But eventually, it worked! I was then able to update the system's main firmware. I don't know for sure, but I feel like the zeroing is a little bit better now with the updates.Quote from: MarkL on June 09, 2015, 04:47:18 pmI've noticed this on high-power sensors. I believe that the long section is an attenuator, though I could be wrong....

author: GlennW87
author_rank: Newbie
timestamp: December 08, 2019, 05:24:22 am
content: pigrew:You seem to really know your stuff with this old power meter. I'm a total novice to GPIB and firmware flashing, however I recently attempted to upgrade the firmware of what was an operation EPM-441a. Took me a while to get my agilent 82357B working but after much trial and tribulation I found myself at the step of downloading software via EMP Dload software utility. About 10 seconds into the download my computer froze and download progress was interrupted. The unit now powers up with the same black screen as seen in the signal path video with faint text reading "starting main firmware" and I can no longer connect via GPIB. Clearly the firmware has been corrupted. Also to note, it had the original DSP A.01.10 firmware so likely this would have caused a failure in my attempt to update it....like i said, NOVICE. Any ideas how I can restore the firmware and unbrick this thing? Also, great to hear about your success with DSP firmware upgrading with the TL866. If I can bring this back to life I will likely try the same.Thanks in advance

author: pigrew
author_rank: Frequent Contributor
timestamp: December 10, 2019, 08:21:25 pm
content: Quote from: GlennW87 on December 08, 2019, 05:24:22 amHi,Yes, the DSP firmware could be the issue, though I'm not sure what the incompatibility is. The update procedures state that A.01.11 is required, so perhaps try updating it next? IIRC, a few extra jumper wires were required for Vdd on the PLCC adapter. I'd suggest buying a replacement EEPROM, and testing your ability to program it first. I have a suspicion that calibration constants may also be cleared when updating the firmware. These should be stored in the backup files generated during the upgrade. You may be able to use a recovery mode with the firmware backup that the update utility creates, if you still have it.If that doesn't work, you'll probably need to pull the main board's EEPROM and reprogram the firmware with your TL866.‎Shahriar's unit had failed SRAM. It's possible that you have that issue too, and the new firmware exposed the issue, but my gut feeling is that this coincidence would be unlikely.-Nathan