FLUKE 335D DC VOLTAGE   - Page 1
Forum section: electronics / repair

author: sdk.61
author_rank: Contributor
timestamp: September 18, 2015, 01:05:38 pm
content: Hi,I hava a FLUKE 335D DC voltmeter. The divice was not working. The rezistance (R8) was broke down on high voltage mainboard. I fix it, voltmeter is working now, output signal is 1,2 V (DC), But I need to see ~1000V. I check all input signals. I need help.Thanks

author: picburner
author_rank: Frequent Contributor
timestamp: September 18, 2015, 02:43:46 pm
content: If you haven't already it, this is the link to the manual with the schematic:http://assets.fluke.com/manuals/335A_D__imeng0000.pdf

author: dacman
author_rank: Frequent Contributor
timestamp: September 18, 2015, 10:44:09 pm
content: Check all the electrolytic capacitors, on all the boards.

author: sdk.61
author_rank: Contributor
timestamp: September 19, 2015, 06:52:19 am
content: device doesn't output I changed the capacitors

author: singapol
author_rank: Frequent Contributor
timestamp: September 19, 2015, 10:48:44 am
content: This is a potentially dangerous piece of equipment, I hope you know what you are doing but I thinking you don't. Download the service manual provided above and read it carefully. You say voltmeter is working...but I don't think you understand because you said you replaced R8 but this part is for the 100 volt range and say you expect 1000V? Even if you expect 1 - 1000V you must set the range switch to the correct range. Before you do so if you have read the instructions.You must configure the front panel binding post to function as a voltage source or a voltmeter.See page 2-5. The common should not be connected to earth ground. If this is correct thenturn vernier and trip controls fully clockwise.Even so make sure the covers are back in place as there are safety interlock switches to protect userbefore equipment can function.First set to 10 V range if there is any output of course you need to set the numerical swicthes. If there is output you at least know that this range is working and then go on to 100V and 1KV respectively. if in the event there is no output then something is not working so you need tomeasure power supply voltages at the main transformer.Here is what you can expect from main transformer: 32Vac.,22V, 17V, 2 X 44V ( center tap), 2 X 10V, 115V, 6.3V, 500V. These are secondary coil but at the primary there is preregulator ac input.If all trhese are correct then go on to the rest of the power circuit.

author: sdk.61
author_rank: Contributor
timestamp: September 19, 2015, 11:05:25 am
content: I have a FLUKE 335D DC voltmeter. not working. resistor (R8) was broke down on high voltage main board. I fix it, voltmeter is working now, output signal is 1,2 V (DC), But I need to see ~1000V. I was check all input signals. I need help.

author: singapol
author_rank: Frequent Contributor
timestamp: September 19, 2015, 03:44:46 pm
content: You have not provided enough information about what you have done. Like what capacitors you have changed in what part of the circuit and what input signals you have tested or checked. you say you need to see 1000v...are you saying the 10V and 100V range is working fine but not the 1000V range?Edit: This may be useful...https://www.eevblog.com/forum/testgear/fluke-332baf-in-the-slaughterhousehttps://www.eevblog.com/forum/testgear/fluke-332baf-in-the-slaughterhouse/15

author: sdk.61
author_rank: Contributor
timestamp: September 21, 2015, 07:18:20 am
content: first thank me for helping Fluke 335D 10V 100V 1000V of from the device output I need to see the values, but only 1.2 volts from the exit of the device comes pre-regulator on the card high-power diode open circuit I switched R34 R33 R32 R31 R30 SERIES PASS ELEMENT in the resistor circuit in the card R28 R43 must come to the input of 150V supply, but why he is coming 135V Or somewhere there is a malfunction thanks

author: singapol
author_rank: Frequent Contributor
timestamp: September 21, 2015, 06:12:19 pm
content: Quote from: sdk.61 on September 21, 2015, 07:18:20 amIf I understand you correctly you are asking why 150V input is 132V only. Refer to DRW6 325A - 1001sheet 2,3 of 6 of pass element. R28 - R34 gets 150V. This 150V comes from rectified 115 Vac of main power transformer pin 14-15. Refer to DRW 335A - 1004 sheet 1 of 3.Please check if pin 14 and 15 there is 115 Vac present. Then go on to bridge diodes CR1-4. You should get 150V after the bridge diodes.

author: dacman
author_rank: Frequent Contributor
timestamp: September 22, 2015, 11:22:27 pm
content: 1.2 Vdc at the output is about what I'd expect if the high voltage circuit did not energize, which could be due to the interlock switches not being closed (there is one each on both the top and bottom), or the relay in the back might be bad. There is also a power-on time-out circuit that uses a relay.

author: sdk.61
author_rank: Contributor
timestamp: September 28, 2015, 07:28:48 am
content: Quote from: dacman on September 22, 2015, 11:22:27 pmhiI don't understand you should explain a bit more detailedthanks

author: sdk.61
author_rank: Contributor
timestamp: September 28, 2015, 09:55:43 am
content: hithe device is working, and is now in ibreside, but doesn't exitthanks

author: singapol
author_rank: Frequent Contributor
timestamp: September 28, 2015, 05:49:11 pm
content: Quote from: sdk.61 on September 28, 2015, 09:55:43 amWhat does ibreside mean?

author: sdk.61
author_rank: Contributor
timestamp: September 28, 2015, 08:13:52 pm
content: hiThe analog indicator on the front panel gives energyto the device when it works but dosen't give the outputthanks

author: dacman
author_rank: Frequent Contributor
timestamp: September 28, 2015, 11:14:41 pm
content: Quote from: sdk.61 on September 28, 2015, 08:13:52 pmIf the output of the 335D is working and there is no indication on the front panel analog meter, the problem is usually bad switch contacts on the sensitivity switch. (Also, exercise it a few times and ensure that it's set to V.) I'd use an ink eraser to clean the switch, then lubricate it afterward.http://www.amazon.com/Perfection-Eraser-Pencil-Removal-Quanity/dp/B0018BZYYM/ref=sr_1_3?s=office-products&ie=UTF8&qid=1443481826&sr=1-3&keywords=faber+castell+ink+eraserhttp://www.amazon.com/Faber-Castell-Perfection-Eraser-Pencils/dp/B005DQ16TK/ref=sr_1_2?s=arts-crafts&ie=UTF8&qid=1443481340&sr=1-2&keywords=faber-castell+ink+eraser

author: sdk.61
author_rank: Contributor
timestamp: September 29, 2015, 07:03:49 am
content: If the output of the 335D is working and there is no indication on the front panel analog meter, the problem is usually bad switch contacts on the sensitivity switch. (Also, exercise it a few times and ensure that it's set to V.) I'd use an ink eraser to clean the switch, then lubricate it afterward.mr. dacmanI don't understand.

author: dacman
author_rank: Frequent Contributor
timestamp: September 29, 2015, 10:30:39 pm
content: Does the 335D output work?Does the front panel indicator indicate the output?Do you know anyone that speaks English?

author: sdk.61
author_rank: Contributor
timestamp: September 30, 2015, 04:55:59 am
content: hiFront panel output does not show The 335d does't give outputthaks

author: sdk.61
author_rank: Contributor
timestamp: December 28, 2015, 01:02:53 pm
content: http://assets.fluke.com/manuals/335d____imeng0100.pdfI can help me

author: sdk.61
author_rank: Contributor
timestamp: December 28, 2015, 01:11:58 pm
content: hithis is the device does not workbut 0 -1000V need to comethanks