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Multimeter | Clamp meter | Insulation Resistance Tester | Panel Meter | Oscilloscopes | Test leads & Accessories | Software Updates => Handheld multimeter => Topic started by: Kiriakos GR on August 28, 2015, 11:37:45 AM
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In 2013 Bosch thought to promote their Bosch Workshop pack of tools, this is dedicated for automotive diagnosis.
Among the offered products is this Bosch MMD 302 multimeter which seems definably to be OEM work from Asia.
While this multimeter it does have a product design that belong to 1990, there is no available crucial information about it specification of display update speed.
In the past 10 years this it has become a habit of many vendors, anything worthless as multimeter they baptize it as automotive multimeter.
Naturally there is exceptions, when the multimeter including functions dedicated to car engine measurements.
While it is not my intention to bash Bosch, if some one ever end up in this topic, he should be aware that this MMD 302 it is a budget made multimeter, and as such, this is not recommended for electronics or industrial electrical applications.
No matter of how big fun you are of Bosch tools? In our times 2010 ~ 2015 the description of multimeter it did changed regarding content, now we have superior multimeter which them are now rocket fast, safer, and even able for advanced measurements which some of them previously was possible only by an oscilloscope.
(https://www.ittsb.eu/forum/proxy.php?request=http%3A%2F%2Faa-boschww-kr.resource.bosch.com%2Fmedia%2Fww%2Fproducts%2Ftest_equipment_products_workshopworld%2Fengine_sytem_testing_testingequipment_products_workshopworld%2FFSA_MMD_302_GB_734x350_w734.jpg&hash=edc2eb53278aae77f22e7cf7497b1767870a1d36)
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All mighty bosch,thank you kyriakos
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I think it is sad thing that one manufacturer as Bosch try to steal the job from the proper manufactures for this part of the market.
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In our days this is not a Bosch - Germany brand.
This company moved their 90% of production in China, therefore this is a modern OEM Bosch - China branding which has nothing to do with moral values.
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Hello everyone! I have one of these Bosch mmd 302 to fix, but without an electrical schematic I canot find the correct value of the Vr3 resistor. He was lost and only the terminals remained. Thanks on advance if anyone has one and can look at the value of the resistor. Below is the image of the position of the missing component.
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Find only this options : Attachments and other options
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Don't use smileys.
Using firefox
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This entire board has different settings from all others.
I did Fix it ... now you can post attachments.
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Thanks Kiriakos, I edit the post above with the image.
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I never have the chance to see such a meter internals.
I was hope this to be another Mastech PCB clone ... But this is different.
Which function this not functioning due this damaged pot ?
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AC / DC voltage and capacitance read but no longer have correct over read adjustment. Continuity (beep), resistance, frequency, RPM and current strength are OK.
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rotnei,
I have few ideas of my own, about suggesting to you .... trying few random values of pots and see which works best.
But more appropriate way this is you to contact Bosch, and ask their help and to test their after sales support ability. :)
Did you request schematic by them yet ? If not try it and let me know tomorrow or when you will have news.
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The circuit configuration its a simple divider, from 10k to 100kOhm works, but I not trust on the device consumption and stability at all. Again, thanks for the help.
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rotnei,
All such calibration pots are famous for instability ( especially at handheld products due vibrations).
Modern multimeter design 2005 and later they have as standard, calibration functions due software ( Goodbye Pots ). :)
Test and Trial of few pots stating of high value ( 100K ), this is a good way to start your repair.
Few years back I was had an personal archive of ancient (low cost) multimeter schematics, as assistance for repairs, later on I did realize that restoration of ancient meters, this is bad for our brain cells.
Modern tools are so much faster with new functions, these making them 80% more productive and compatible to modern applications.
This Bosch meter internals (components) are interesting, this meter using high quality parts, and this translates to improved electrical safety for the user, and also better accuracy in Law of Ohm measurements.
I wish you good luck at repairing it.