Fluke 123 scope only click sound from speaker - Page 1
Forum section: electronics / repair

author: Jogas
author_rank: Contributor
timestamp: May 23, 2019, 08:03:31 pm
content: Hi every one.any idea why only click sound on my scope and nothing else.Does scope should turn on even no battery connected? Because battery poor condition.I disassemble unit nothing look bad nothing burned not a single sign .thanks in advance

author: dacman
author_rank: Frequent Contributor
timestamp: May 29, 2019, 09:00:34 pm
content: Most of Fluke's scopes need a good battery even when powered from the ac adapter (such as also the 190 or 199 series). If the power adapter is used and the scope is turned on and it just beeps and nothing else (or the screen momentarily flashes and nothing else) or nothing at all happens, a known good battery should be installed as a first step and this will usually fix it.A battery pack for the 123 cost about $135 US. If you get the $30 knock-off, you're on your own.

author: mahi
author_rank: Regular Contributor
timestamp: May 30, 2019, 11:13:07 am
content: Jogas:I just tried this with my Fluke 123 ScopeMeter and it powers up just fine on AC power without battery pack installed.dacman:That does not seem the case. I also tried this with a 105B and 199C and both work fine without battery pack installed.

author: Samogon
author_rank: Frequent Contributor
timestamp: May 30, 2019, 06:59:05 pm
content: Confirm what mahi saidI would start checking power IC service manual has nice theory of operation. Check if it generates all voltages and signals needed

author: dacman
author_rank: Frequent Contributor
timestamp: June 01, 2019, 11:01:08 pm
content: I don't remember ever trying to power one without a battery installed. One symptom of a bad battery is that the unit will not power on (due to the battery) even when powered from an ac adapter.

author: Jogas
author_rank: Contributor
timestamp: June 02, 2019, 09:07:14 pm
content: Hi thanks all at first thanks for coming here to help me out.I download service manual and I try to read.i have battery very poor but I was thinking that should turn on without aswell.batteryin meter was probably connected wrong and unit got damaged.battery plug pins was soldered and sensor wire (white)was mixed with positive wire (red ).I find out by googling pinout.i hope we can sort this fix out.On battery is resistor and temp sensor. What resistance should be on resistor maybe someone know.Sorry for my english and grammar it's not my main languge.

author: Samogon
author_rank: Frequent Contributor
timestamp: June 03, 2019, 07:35:41 am
content: There should not be resistors inside battery, i think thermistor is usual 10k, i have one battery open will measure its resistance tomorrow

author: Jogas
author_rank: Contributor
timestamp: June 03, 2019, 08:03:49 am
content: Here is photo

author: Samogon
author_rank: Frequent Contributor
timestamp: June 04, 2019, 06:02:13 am
content: Yep 10k thermistor

author: Samogon
author_rank: Frequent Contributor
timestamp: June 09, 2019, 03:54:48 pm
content: Taking back my statement about starting scopes without battery, at least i have checked 199c it wont start without or with weak battery.

author: mahi
author_rank: Regular Contributor
timestamp: June 09, 2019, 04:11:09 pm
content: Samogon:Did you use the proper power supply? The Fluke 123 power supply looks identical to that of the 199C but the voltage is lower (15V vs 17.8V). Just wondering because my 199C does work without battery.

author: Jogas
author_rank: Contributor
timestamp: June 12, 2019, 07:58:16 pm
content: Hi yes I use power supply that came with unit

author: Smith
author_rank: Frequent Contributor
timestamp: June 15, 2019, 06:15:41 am
content: I can confirm the Fluke 105B works without battery using the original adapter. The battery died more than 10 years ago, we removed it and never replaced it.

author: Agd
author_rank: Newbie
timestamp: March 10, 2025, 01:38:03 am
content: i am with a problem like this, someone know something about that?