Wednesday, December 11, 2013
We’re having a snowpocalypse here in the Willamette valley, so I haven’t been doing much beyond keeping warm and bypassing frozen pipes…it was down to –7F at one point making it colder than Ukraine.
Busted pipe…sediment/iron seems to settle when the water is slow & cold which is why it looks like root beer.
Now the list of stuff you can buy on Amazon and send to your boring friends:
- The Waste Books (New York Review Books Classics)
My current reading, by this guy, humorous and philosophical.
- The Middleman: The Complete Series
I can’t believe there people who haven’t watched this show, just brilliant.
- To War With Whitaker: Wartime Diaries Of The Countess Of Ranfurly, 1939-45
I like a woman with spunk.
- Hakko 808-KIT/P Self Contained Desoldering Gun with Internal Vacuum Pump and Carrying Case, 120V AC
I just bought one for myself but haven’t had time to try it out. Going by reviews it will be pure luxury when replacing components in repairs.
- B&M Brown Bread Original, 16 Ounce Cans (Pack of 12)
Go ahead, you know you want bread in a can.
- Samsung Electronics 840 EVO-Series 500GB 2.5-Inch SATA III Solid State Drive MZ-7TE500BW
I need one. You should buy me one.
- Probe Master DMM Test Lead Kit, Softie, Rt. Angle Safety
These look like really nice leads.
- Hosa Cable D5S6 Deoxit Contact Cleaner Spray
This stuff has “repaired” a bunch of balky devices of late.
Sunday, November 03, 2013
Cleaned up the last (or first) terminal. It had pretty bad pitting but not in the area of contact with the battery.
Just some more PCB pics.
I bent up a crude replacement for the “SPRING, BATTERY” from .040 music wire, by hand. Yes, I’ll probably buy a replacement from Fluke but they only handle orders over the phone and that’s my least favorite way of ordering replacement parts. Just let me shoot you an email, Fluke. Better yet, let me send you a link to this 2 part blog post.
I need two of MP8 “SPRING, BATTERY”, two of MP9 “COVER, BATTERY (OVERMOLDED)” and two of BP1 “UNNAMED FLAT SPRING BATTERY CONTACT THAT CORRODES IF YOU GLANCE AT IT WITH A WRY EXPRESSION”.
Pregnant Walrus Man
The signature will make more sense in a couple of pictures. Anyway, I digress.
Seems to work.
Three working meters!
My test setup. A 60 watt bulb in a light plugged into a Tekpower M920 AC Line Splitter. I bought it because it was the cheapest one on Amazon that would ship via Prime, the more expensive ones didn’t seem like they had better functionality or quality.
Clamp on the X1 coil, leads (not Fluke leads, I didn’t get this type with the meters…) held against contacts on the line splitter. I’d love one of these that just had banana jacks for voltage.
I tested all three meters, just checking Volt, Amp and Watt readings. They all agree to within .3V, .01A and 1W. Not bad. I imagine they are all out of calibration though.
I look like a pregnant walrus. Felice always takes flattering pictures of me.
So this is a better shot of the test setup.
Now let’s test a APC ES-550 UPS! Fun!
On line power.
On battery power. A square/trapezoid wave with lots of ripple.
Line voltage, 2.7% THD.
Battery voltage, 48.5% THD.
How about a Cyber-Power 585AVR? Line voltage.
Under battery power.
After a minute it dropped 2 volts and then stayed pretty stable. I didn’t run the test for longer as this was more of a lazy Sunday entertainment.
In any case it seems like the meters work. Yay me.
When I opened up the battery compartments I found out why they were being sold…full of battery corrosion.
This one actually had the batteries. Rather than standard decomposition they seemed to have just gotten really rusty, so much so that metal was horribly eaten.
Regular alkaline crust, but in significantly larger amounts than I’m used to. The meters take 4 C cells. Happily most was contained in the battery compartment cover, which is good. If they had been stored upside down things could have been much worse.
6 screws and some gentle prying with a feeler gage opened the first one up.
The “Spring, Battery” was eaten through.
The terminal is really crusty. Part #BP1. I don’t see reference to it in the service manual beyond it being shown in the schematic. I should call up Fluke and see if I can get replacements.
Some glamour shots.
In order to remove the main board you have to unlatch a ZIF socket from the flat cable.
The amperage BNC connector leads slip out but the voltage wires are soldered to the board.
LCD display board.
Notice the Zebra connector.
Better shots of the BNC leads.
2nd meter has crust on the same terminal…
Third meter is not corroded!
A quick dip in vinegar for the 2nd one’s terminal. The first one I’ll save for later…Not too bad but the plating is stripped off. I ‘m unsure as to whether or not the contact is beryllium copper but I’m generally paranoid so I won’t be cleaning it with abrasive methods.
Vinegar neutralizing the alkaline deposits. Note the rusty one is not bubbling.
All cleaned up, and dried off.
I’ve never seen corrosion eat plastic before. I’ve heard several different theories, that there are additives in the plastic that allowed the corrosion to penetrate, that it released heat that allowed the plastic to decompose, or that it was a thermoplastic that was susceptible to alkaline attack. In any case that’s pretty amazing. The covers were attacked more than the body, which is good.
Well two are working!
Yes, I decided that maximum boredom could be produced by making this a two parter…more to come…Part 2.