Unsafe solar controller

This solar controller came in for recycling.

Notice the New Zealand mains plug used as part of the wiring.  This is potentially dangerous.  There is a possibility that it could be plugged into 230V AC mains power.  At best it would just blow up the controller and at worst it could electrocute someone.  These solar controllers only work up to about 20V.

This reminds me of the time I was repairing TVs back in the early 1980s.  Someone came in with a Pye Vidmatic portable colour TV (they were made by Sharp) that could run on 230V AC and 12V DC.  It had a mains plug on the 12V input.  The customer said he wired up 12V DC on his boat using mains plugs and sockets!  He said the TV would no longer work on 12V.  Funnily enough the 12V DC input fuse was blown!  It must have had 230V AC fed into the 12V DC input.

The lesson here is that the appropriate connectors should be used.  Mains plugs and sockets should only be used for mains voltages.

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Some bad typos

When I see typos on something that has been produced by the thousands I wonder about the quality of the item.

We came across this BTC keyboard box that has two really serious typos.

“Mothee board”!  “powct supply”!

How can you manage to make those typos?  And how can you miss them on proof reads?

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Good on you Dell

We get a lot of brand new monitor stands in for recycling.  It seems that companies buy monitors and stick them straight on to monitor arms.  I was thinking that the manufacturers should sell the monitors without stands.  This would reduce prices and stop wastage.

Well it turns out that Dell actually supply at least one model without a stand.

Good on you Dell!

Dell P2219H monitor

Here is a Dell P2219H monitor with a stand.

If you need a stand for a monitor we keep a lot of the ones that come in for recycling.

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A real dodgy modification

I came across this real dodgy modification.

This plug board came in for recycling. The original cord has been replaced with one that has no earth. Also, the replacement cable is the older two core type without an outer sheath.

This is really unsafe.  There is no earthing on the sockets.  If something that wasn’t double insulated was plugged in that had leakage from phase to the metal you can get a belt off it and possibly get electrocuted.

The lesson here is: Don’t modify something unless you know what you are doing.

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What is this ATX power supply rating?

Thomas came across this Thermal Master TM-350-PMSR ATX power supply:

350 watts? Yeah right! The mangled English grammar does nothing to instill confidence as well.

Maximum output power is given as 350W but if we add up all of the individual output power ratings we get this:

 12V x 10A  = 120W
  5V x 14A  = 70W
3.3V x 14A  = 46.2W
 -5V x 0.5A = 2.5W
-12V x 0.5A = 6W
  5V x 2A   = 10W (standby)
Total       = 254.7W

Is it a mistake? Is it false advertising?

Turns out that there is a post on the forum at badcaps.net about these power supplies and it is only a 250W power supply.

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Can’t buy these as spare parts

I was looking at repairing a Panasonic microwave oven yesterday.  Customer said it went bang.  Yep!  It went bang! The current sense resistor in the switch mode power supply had gone splat all over the PCB.  The  control ic has probably gone.  I didn’t bother to check it.  It is pretty much a given that it is shorted.  It is one of those eight pin jobs.  To me it is always a big ask to have over 300 volts pumping through one of these piddly little ic’s. I suppose it  works ok because there are millions and millions of these little babies doing their job perfectly well for years and years all over the place.

So I looked up the specs on the ic.  It is a MIP2K4 made by Matsushita.  When I got to the end of the data sheet I came across this:

That left me spluttering!  The buggers at Matsushita only sell them to Japanese companies! And I bet it has to be in production quantities.

Big sigh…..  Another bit of gear that I can’t repair down to component level.

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Leunig, life and e-waste

It is a very good question!

Image: Courtesy of Michael Leunig.

We get a lot of this sort of stuff coming in for recycling.

Maybe our customers are trying to avoid that question?  I know that I don’t want to be asked that sort of thing by a bunch of cables and stuff!

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Peter’s homemade e-bike

Check out Peter’s homemade e-bike.The battery pack housing is from a recycled NZ Post e-bike battery that Peter repacked with recycled 18650 cells.  The battery pack housing and the 18650s are from us here at Ecotech Services.  Peter sourced the hub motor from overseas and it was easily retrofitted to the Marin bike frame.

Good on ya Peter!  Nice job!

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Free repairs on International Repair Day

To celebrate International Repair Day Ecotech Services is offering free evaluation and repair on a wide range of faulty electrical, electronic and computer equipment.

The event will be held in the carpark at 139 Wordsworth St, Sydenham between 9:00am and 5:00pm on Saturday the 20th of October. Experienced, registered technicians will be present to evaluate and if possible carry out the repair of any item that uses electricity. Parts and tools may be made available for individuals to repair their own items. If wet the event will be postponed to the following Saturday.

A press release on the event can be seen here.

Further information

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Bad design on a Megger MIT220

I had a Megger MIT220 meter come in for repair from Dells Appliances, our related company.  It was not giving a reading.  It was an easy fix.

The wire broke!

The wire had broken of the test lead terminal inside the meter. After taking it apart it was obvious what actually caused the fault. The metal contact of the terminal could rotate inside the terminal housing by about a millimetre either way. With usage the solid core wire eventually broke due to metal fatigue.

I did a permanent fix by gluing the contact in place.

This is a case of poor design.  They did a nice job with tying down the two wires so I don’t think it is something that could have been overlooked.  Also design engineers should realise that solid core wires should not be used where there is any possibility of movement.

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