Fluke 5100 Repair advice and service manuals sort - Page 1
Forum section: electronics / repair

author: Mav_2014
author_rank: Contributor
timestamp: March 10, 2018, 10:40:35 am
content: Hey all!So, Fluke 5100 sat for a number if years, shows and err4 and err6 fault, suspecting the err6 is in relation to the high voltage output with a fault over 20v.I know a few on here have worked with and on these back in the day so I'm looking for a bit of assistance, troubleshooting and somewhere to locate a service manual? Hopefully I'll be able to post some pictures of the teardown and help along the way in return

author: dacman
author_rank: Frequent Contributor
timestamp: March 11, 2018, 01:05:03 am
content: Just Google for Fluke manuals and on the Fluke website search for 5100. There is a manual and a supplement with change data.

author: Mav_2014
author_rank: Contributor
timestamp: March 11, 2018, 01:18:36 am
content: I've found the user manuals but nothing on the service and calibration side

author: dacman
author_rank: Frequent Contributor
timestamp: March 11, 2018, 02:29:22 am
content: The instruction manual that is hosted on the Fluke website has a calibration section starting at paragraph 4-76, a performance test section starting at paragraph 4-39, troubleshooting tables starting at paragraph 4-119 on page 4-29, board layouts and parts lists in section 5, options in sections 6, and schematics in section 7.

author: Mav_2014
author_rank: Contributor
timestamp: March 11, 2018, 10:26:02 am
content: Top man! I shall have a look through and see what can be found. I'll try and do a teardown of the beast along the way!

author: LaserEng
author_rank: Regular Contributor
timestamp: February 11, 2019, 04:34:55 pm
content: Apologies for awakening this thread but just in case someone else comes on to this thread looking for possible faults for error 6 on a Fluke 5100B/5101B/5102B calibrator I have just repaired one which had an error 6.The calibrator would immediately display Err 6 as soon as power was applied but would actually work ok up to a couple of hundred volts DC and AC, don't remember exact values and also current was OK. As the manual said it was something wrong with the High Voltage board it sent me on a wild goose chase and I was initially thinking that the CPU was looking for an ACK signal from the HV board but this turned out to be a red herring.As I was chasing this fault a Tantalum cap on the A17 power amplifier board decided to spill it's guts which turned out to be a sign pointing to the board with the problem causing Err 6. After replacing the tantalum cap I decided to follow some of the tests in the service manual for this board and one of them was to short the input of the HF amp with a jumper wire between TP23 and TP27 and look for 0V on the output of the amp on TP4 and TP23 but mine was showing a reading of around 35V which indicated a problem in the HF amp.There are multiple revisions of the A17 board but there was a major difference between early boards and later boards, the board I had was an early one which can be identified by the presence of 3 or 2 on really early boards photoresistors on the left hand edge of the board which look like a plastic tube with 2 legs either side, one side is an led and the other side a Cd photocell.When I started fault finding the HF amp I found that U102 was running quite hot, this is an LM318H op-amp and doing some diode checks with a multimeter around the output of the amp showed something was not right and it seems that one of the output transistors in the LM318H was leaky as replacing this IC got rid of the problem of a high DC voltage on the output of the HF amp with a shorted input.So after fixing that I expected to go back to looking for the cause of Err 6 but since the LM318H has been replaced I have not seen the Err 6 return. I'm still not sure how the CPU was detecting this error but possibly from the OVLD signal but hopefully this will be of help to anyone else fault finding Err 6 as it seems to be a fairly common issue with these calibrators.

author: Paceguy
author_rank: Regular Contributor
timestamp: August 08, 2019, 01:24:41 pm
content: Just saw this post. I have the same error 6 problem with one of my 5100B's. I will follow what you did and hopefully find the problem. Thanks for this post!

author: casinada
author_rank: Frequent Contributor
timestamp: August 10, 2019, 06:38:59 am
content: http://www.ko4bb.com/getsimple/index.php?id=manuals&dir=Flukehttp://bama.edebris.com/manuals/fluke/5100b/There are many variations and boards inside the 5100 series of calibrators and there as many manuals. The repairs on this units are not simple and you need some raiser boards to be able to reach most of the components to test.

author: Johnny10
author_rank: Frequent Contributor
timestamp: October 23, 2019, 10:47:21 pm
content: I have the 5101B on the bench and everything thing seems to work except AC or DC voltage over 19 volts.What did you decide problem is?I haven't studied the whole thing yet.

author: picburner
author_rank: Frequent Contributor
timestamp: October 25, 2019, 09:56:15 am
content: This equipment, due to its advanced age, is a real disaster.Whenever I need it when I switch it on it goes in protection and I have to replace a tantalum capacitor, now I've replaced almost all of themIf it works properly for voltages below 20V and goes into protection or does not generate voltages above 20V you must check the section "A16 High voltage PCA" for diodes in short circuit, damn tantalum capacitors etc.

author: Johnny10
author_rank: Frequent Contributor
timestamp: November 03, 2019, 08:37:30 pm
content: I decided to move on and put the 5101 off for now.After spending so much time on my Datron 4000 calibrators. I know that right now I am not interested in falling down another rabbit hole.

author: bdunham7
author_rank: Super Contributor
timestamp: August 29, 2020, 02:30:48 pm
content: Quote from: casinada on August 10, 2019, 06:38:59 amHi y'all! I've got a 5100B and 5101B on the bench (and floor and all around) in for repairs and I thought this would be a good thread to revive--or we can start new one. It looks like a few of you havethese units still hanging around unrepaired--I'm trying to avoid that fate.Casinada, thanks for the links. I struggled through a power supply regulator problem on the 5101B with the manual on the Fluke website, but it was obvious that there were schematic differences. I got it working enough for testing by bypassing some stuff, but not good enough for a final fix. One of your links has the right schematic.Johnny10, does your unit have current range output? I found that inop high voltage DC, low frequency AC and current were due to faulty contacts in the K8 relay on the power amplifier board. HF AC still worked.I've got the 5100B almost fixed--everything works except my negative low current ranges are just out of spec and there doesn't seem to be any way to get it dialed in.The 5101B is a disaster, someone already gave it a go and I got it in pieces. Right now I have an erratic/flickering/useless display and everything is removed except the controller and the front panel stuff. Ideas are welcome.

author: Johnny10
author_rank: Frequent Contributor
timestamp: August 29, 2020, 05:36:51 pm
content: I let the Fluke 5101 go to a better place after thinking about how much work I would be putting into it.I am a Datron guy.With two 4000 series and I think 3- 1062 LS101 Digital meters all repaired. And working well until ... another Tantalum blows!Good Luck on your units.