Fluke 233 - need help, trying to repair it - Page 1
Forum section: electronics / beginners

author: gazdamissa
author_rank: Newbie
timestamp: July 19, 2015, 05:43:40 pm
content: Hi,I have Fluke 233, which cannot power-up. I bought it over internet flea market, way-way under the price, and thought I could fix it. As it turns out, it is going to be trouble. Previous owner does not know what happened to it, just that it shows error light.When switched on, red warning light stays on, display does not show anything, or shows number 1.Connected to a power supply, I can see that display is pulling 500mA all the time. I read some posts regarding power consumption, and as I can remember, 5-20mA is supposed to be OK. This, is not.Found in the user manual how to reset some possible password protections. It is supposed to short couple of pins, and that's it. Well, tried that, nothing happened.I took it over to a friend that is more skilled to take a look at the display board itself. It was obvious somebody tried to repair it. couple of components were visibly resoldered.We used pictures from this forum as a guide, and found out some components are missing.R212, R211, Q203.We tried to power up display again, it pulls 500mA, and microcontroller gets REALLY hot in seconds. Disconnect. It is M430F448. We think this chip is shorted inside, probably took some electrical shock. This chip is freakishly expensive in my country, it has to be custom-ordered, around 130 euros. No, thanks.Ordered it from china, 5 pieces for 15$. I have to learn how to replace it until spares arrive.Also, one sot23 diode (CR203) show short when in circuit, so we removed it to test. It was good, soldered back.At this point, I don't know what else to try, suggestions are welcome.My question is, can somebody who has this multimeter check what are those components that are missing?I know those are two resistors and a transistor, but don't know values.I can't see markings on pictures that are posted in this forum.Thanks in advance, Missa

author: gazdamissa
author_rank: Newbie
timestamp: July 24, 2015, 04:00:23 am
content: Nobody has this multimeter? Darn...Controllers arrived at customs. Will arrive sometime next week. I still don't have info on those 3 elements...Somebody, please check on their multimeter. Or, give me link for service manual, if such exist.

author: tron9000
author_rank: Frequent Contributor
timestamp: July 24, 2015, 09:48:50 am
content: Have you tried searching the equipment repairs section?

author: gazdamissa
author_rank: Newbie
timestamp: July 25, 2015, 06:10:51 pm
content: Well, I searched topics, found one, and mailed OP privately, until now no response from him.I read some similar topics, but nothing I can see that is helpful.

author: Monkeh
author_rank: Super Contributor
timestamp: July 25, 2015, 06:13:37 pm
content: If you replace the microcontroller the meter won't do anything, because it won't be programmed.

author: gazdamissa
author_rank: Newbie
timestamp: July 28, 2015, 02:05:27 pm
content: On its datasheet says it is mixed signal microcontroller, so I thought it is universally pre-programmed. Well...edit:Have read datasheet more carefully, GPIO pins, flash memory, ram, darn. it has jtag or usb interface, though. Maybe I could cram software in it if I find it somewhere...We'll see. Something is going to blow up...

author: Monkeh
author_rank: Super Contributor
timestamp: July 28, 2015, 04:05:39 pm
content: Quote from: gazdamissa on July 28, 2015, 02:05:27 pmYeah, no, definitely not preprogrammed..You won't find the firmware anywhere. You'd be better off getting Fluke to repair it, if they will now you've messed with it.

author: gazdamissa
author_rank: Newbie
timestamp: July 30, 2015, 03:29:22 am
content: First thing I did was sending it to authorized fluke service. After month of waiting, they returned it with explanation "unable to repair". I know for a fact that they did net even open it.

author: MetalHead
author_rank: Contributor
timestamp: July 10, 2022, 05:44:48 pm
content: Have same issue.. have you fixed yours?

author: BeBuLamar
author_rank: Super Contributor
timestamp: July 10, 2022, 09:35:40 pm
content: I used it for a short time. Didn't like it. I am not sure who in my company has it now. I use an 87V instead,