WTB: FLUKE 8600A IC

Hi, all out there... I'm have just bought an broken FLUKE 8600A bench-multimeter. When I power it up, just one digit or all 4 digitpoints lit up. And a relay is buzziring. I'll checked the voltage inside the unit. I found that the +15/-15 volts was very low. About +8 and -1.6 volts. I pull out the big IC, U8, and there I have my voltage back as they should be.

So I strongly beleave that the 40-pin IC is bad. It's labeld : MPS7107 and dated 7505. In a schematic I got for the instrument, it say "Custom CMOS DVM chip", so it's not a standard component. Is there someone out there have such a IC in there junk-box, and want to sell it to me? Pls send me an email if You got it.

With the very best regards from SWEDEN

Bo-Lennart Karlsson snipped-for-privacy@Telia.com

Merry Christmas to all of You!!!

Reply to
Bo-Lennart
Loading thread data ...

Hello, I think your 40pin i.c. is simply an ICL7107 multimeter display driver for leds,the equivalent for lcd would be the ICL7106.

I think INTERSIL amongst others,make/made this i.c.

regards doug. in U.K

Reply to
doug

But why do you think that? Merely because it was a popular voltmeter IC does not mean it's what is used. Fluke is a big enough test equipment manufacturer that it seems likely that it is worth their while to use custom ICs. Let's not forget that the Intersil IC is thirty years old, and is merely a voltmeter IC. It takes a fair amount of external circuitry to make it into an actual DMM, and when making a lot of DMMs it's usually worth getting as much integration as possible. What was ground breaking in '77 or '78 isn't groundbreaking 30 years later.

I've never opened one of those $9.95 DMMs with wired in test leads and flat as possible but I doubt they would use a voltmeter IC that requires a bunch of other ICs to get a complete set of functions. And if they can get it all into a blob of epoxy, there's even less reason for Fluke to use multiple ICs.

That said, your suggestion isn't completely bad. Because again, it's always worth putting in some time before trying to track down an expensive and hard to get IC. So the original poster can go through known voltmeter ICs, and see if there is any common ground between the "sample circuit" in the datasheets and the actual meter. A quick glance will say one way or another, it's when there is a match on some analog component (since those are few they are an easy way to check) that more work is required, because then one has to see if the premise actually goes all the way.

Michael

Reply to
Michael Black

Here's one for 40 bucks buy-it-now.

formatting link

On the plus side you'd then have a parts unit to pick from. On the minus side you'd need someone to buy it for you, as the guy will only ship to US or Canada.

Reply to
JW

...

...

... JW wrote:

Heck, I've got an 8600A I'd sell for $30 (whole thing, you can pull the chip yourself), but I'm darned if I know how I'd get it shipped to Sweden. I suppose I could pull the chip and stick it in an antistatic bag to make the shipping less, but there's still the hassle (customs and what-not) and cost of getting it shipped at any size. Looks like more than $45 to ship a half-pound (quarter kilo) from here to there. Seems rather expensive for fixing a 32 year old 3.5 digit meter, especially if the chip does not turn out to be the whole problem.

--
Cats, coffee, chocolate...vices to live by
Reply to
Ecnerwal

I checked. Different pinout and function.

RL

Reply to
legg

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.