Agilent U1604A 40MHz Handheld Dual Channel Digital Oscilloscope - Page 1
Forum section: electronics / repair

author: HandBuilt
author_rank: Newbie
timestamp: April 06, 2018, 03:29:11 pm
content: Hello all !I recently picked up on of these handhelds from ebay. It does not power up, no led ...zip. There is voltage getting to the battery three pin connector when I plug in the power supply.It did not come with a battery and only one screw holding the covers onSomeone has been poking aroundDoes anyone know if the unit will power up without the battery connected?Could someone kindly help me track down a schematic for this unit please. It has a multi level pc board so its a bit tough to trace.Cheers !

author: Samogon
author_rank: Frequent Contributor
timestamp: April 06, 2018, 07:20:47 pm
content: If i remember correctly it was required battery to startup.

author: HandBuilt
author_rank: Newbie
timestamp: April 07, 2018, 06:13:37 pm
content: Shoot, thought I found a schematichttp://www.circuit-encyclopedia.com/showinfo-30-396287-0.html#ecmscome back with a 404 error"contact us" just brings you back to the top of the page.

author: Samogon
author_rank: Frequent Contributor
timestamp: April 07, 2018, 06:38:22 pm
content: Most of the sites claiming that they have unobtainium schematics and service manuals are fakes.

author: HandBuilt
author_rank: Newbie
timestamp: April 07, 2018, 08:40:46 pm
content: The amount of work some people go through to scam ya...sheeshAnyhow, here's some pictures to show what I see.The power supply is 12.2VDC. that is coming out the battery connector along with 2.00vdc (for temp sensor?)Does anyone recognize the Battery connector plug type so I can order a plug for it to build a battery?All the diodes seem to measure good. The coin battery soldered to the board is depleted to 0.3vdcI'm guessing it should be 3V +?I have ordered a ESR meter. Its making its way to me from Japan.Its hard to know what to test next. If you have suggestions, I'm all ears! If you would like more pictures of a different angle or a close-up, please ask.I am pretty new at this as you can probably tell.Thanks for reading this

author: HandBuilt
author_rank: Newbie
timestamp: June 12, 2018, 02:55:16 am
content: If you own one of these units could I please ask to check if it will power up without the 7.2V Battery Pack

author: lowimpedance
author_rank: Super Contributor
timestamp: June 12, 2018, 06:46:41 am
content: Work has a U1602a, I just checked and it does power up without the battery pack connected.No reason to assume the 1604 should be any different in this respect.

author: HandBuilt
author_rank: Newbie
timestamp: June 12, 2018, 01:59:43 pm
content: Thank you! That was a big help, Cheers!

author: DKMac@home
author_rank: Newbie
timestamp: August 22, 2020, 03:44:08 pm
content: Are you still playing with this U1604A ScopemeterI am currently play wit a u1604B model that had the scope fuctions working but no data diplayed in DMM modes, just the dc symbol and the linear bar gragh shown. No reading for Dc,AC,Ohms,Diodes mode

author: ArduinoX
author_rank: Newbie
timestamp: March 16, 2025, 07:28:40 pm
content: This unit in particular came out with a defective factory component parts for the charging section of the battery.