2019-08-17

Electric kettle repair

Cheap electric "cordless" kettle with round base, sold probably under hundreds of brands.
Looks like made from brushed steel but this metal is non-magnetic, so I have doubts.
Symtoms: randomly not working at all (no neon light near the switch, no heating). Mischievously working once or twice after disassembling and reassembling.

 Faulty element: electric switch with integrated thermal switch (aka thermostat switch) - original marking DY-03G T125.
 It might be not worth the effort, but replacement switch is easily available on ebay (TM-XD-3 T125 and various other names), costing $0.99 with free shipping. Disassembling, replacing switch and reassembling kettle is pretty straightforward.
This metal plate at the bottom of the switch is actual element responsible for switching off when boiling starts - it pushes plastic rod inside when temperature arises.

2019-04-23

WIWA HD102 - naprawa

Niesprawna WIWA HD102 (https://commonemitter.blogspot.com/2014/04/wiwa-hd95-i-hd102-porownanie.html).
Objawy:

  • (podobno) wcześniej wyłączał się po czasie
  • częściej/później nie włącza się w ogóle
  • migająca dioda sygnalizująca zasilanie
  • ciche "cykanie" przetwornicy

Brak widocznych objawów uszkodzeń (przegrzanie, spuchnięty kondesator, wyciek z kondensatora).
Naprawa: wymiana kondensatora 47u/25V/105C po stronie pierwotnej przetwornicy (mały kondensator elektrolityczny na lewo od układu VIPer22A).

Magnetic PC case door

This is not a vanity modification - I've got this case for free but it was missing side door. In general I don't mind, but I've finally created replacement side door just to reduce dust collecting inside.
 I bought these 10 neodymium magnets (5x5x2mm) for under $1.

 This semi-sturdy, semi-transparent plastic sheet was cut out from light scattering panel from broken LCD TV - basically electronic waste. It was easy to shape by cutting lines with sharp knive and snapping it.
 Magnets are held with transparent two-component adhesive.
 6 magnets were quite enough to hold it, but as this plastic is little flimsy I've added two extra in the middle of longest edges.

Old PC hardware

Some PC hardware from late 80' and early 90'.
 Motherboard with soldered UMC 486SX 33MHz processor and socket for 487 coprocessor.

Multi I/O ISA card CT-6250.
NS8250 = "original" 8250 UART
MM58176 = real time clock
UCY7406 - Polish TTL - what is doing here?

FDC37C65 Super I/O chip
PAL16L8

HM6666 - based card, http://www.mks.purespace.de/technical/hm6666.htm

HM83450 + W86C451

Other variant of same card

W83757F + W83758P

2019-02-24

Cheap SMD box

It may seem silly, but I'm trying to reuse almost all parts from consumer electronics, including SMD 1206 and 0805 resistors and larger ceramic capacitors (1206 and 0805, 1u - 10u) for DIY projects. Desoldering these may seem like a waste of time, but it's difficult to keep wide range of component values in stock and reusing old one often beats going to shop to buy new one or waiting for shipment.
One way of reusing old components is keeping few scrap boards at hand and scanning them for particular values when needed. Surprisingly this might be easier then looking through desoldered components if they are not sorted, thus sorting is essential.
There are some nice dedicated SMD boxes on ebay/aliexpress, but using polyethylene pill boxes is cheaper.
This pill box, consisting of 7 smaller boxes with 4 compartments each in larger box costs ~$2.50 from local retailer.



 As some edges and corners are not closing precisely, I've put some hot glue on them. As all is stored in larger box, risk of losing anything is minimal and it's easy to identify if any compartment needs attention.