Sharp microwave display failure

Some of the LCD elements (small squares) on the display are failing to light. If I push on the end of the ribbon cable where it connects to the edge of the display driver PC board, the problem elements will start working until I remove the pressure. This leads me to think that the ribbon cable's connection pads are failing. Is there any way to repair the PC connection pads for each conductor of the ribbon cable on the edge of the board? There isn't any hardware connector for the ribbon cable on the board. It connects directly to the pads on the edge.

BTW- This is the second time the display has failed in the same way. I replaced the entire display assembly (LCD and driver board) about two years ago. Cost about $90. The replacement worked fine until recently. Since the home is not occupied in the winter, the heat is turned off. The temperature can get down to well below freezing for days or weeks. Could this be why the display has failed twice?

Thanks

Reply to
Techguy
Loading thread data ...

Wouldn't a whole new oven cost that?

Reply to
Homer J Simpson

This reaffirms my belief that modern Sharp microwaves are crap.

Reply to
grumpy

On Mon, 30 Oct 2006 06:08:47 +0000, Techguy Has Frothed:

I've done it before but without a picture it's hard to tell what you have.

I doubt it. Lots of new stock is stored in non climate controlled areas in the winter.

I would buy a new oven if you can't fix this one for a lot less than 90 bux.

--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794
Reply to
Meat Plow

Not necessarily. I have a Sharp Carousel microwave which I bought new almost seven years ago. Still works almost as well as it did the day I bought it. I say "almost" because every once in a while the machine will refuse to start when the door is closed--it takes a couple of openings and closings to get it to work. This is intermittent; most of the time the microwave works exactly as it should. Very difficult to predict just when it will happen. I think the door switches are either very dirty from grease, etc. or simply wearing out after seven years of daily use.

As to your belief that all recent-vintage Sharp microwave ovens are "crap", that's your opinion and you are entitled to it. However, I don't really think there are many microwaves out there that will last years or decades as the old Amana Radaranges, Tappans, etc. used to. (I recently read in another discussion forum of an Amana Radarange that was still going strong after almost three decades.) Today's microwaves, like just about everything else these days, are made offshore, which often means lower quality, which in turn means the device will not last as long as American-made appliances did. The very low prices of new microwaves these days (I've seen them priced as low as $30) means it is not cost-effective to repair them when they go bad, especially from a major component failure such as the magnetron. Remember that any repair station nowadays will charge a minimum fee just to look at a piece of equipment; this will be in addition to taxes and the cost of any repairs done to the unit. If you paid only $30-$40 or so for the microwave and it will cost $90 to have it repaired, your best bet is to junk the old unit and buy a brand new one; that or simply put up with the defective display, as long as the oven works well otherwise.

Low or downright cold temperatures in and of themselves will not ordinarily kill an electronic device, but they won't do the device any good, either. I would find a way to keep the heat on to maintain a temperature of, say, 68 or 70 degrees F. during the winter in the home where the defective microwave is located, or make arrangements to have someone live in the home during the winter months so that keeping the furnace going will be justified. There are likely other devices such as radios, televisions and the like in the dwelling that are taking a beating from the lack of heat as well.

Kind regards,

Jeff Strieble, WB8NHV (email addy not shown to deter spammers) Fairport Harbor, Ohio USA

Reply to
Jeff, WB8NHV

The microwave is built into the cabinets above the stove with an exhaust fan. A new one would cost at least $200 along with the hassle of removing and installing.

This ribbon cable is a thin plastic strip about 50-mm wide. It has two layers. One layer has the conductive traces imprinted on the inside surface. The other serves as a backing layer to protect the traces. The back surface of the ribbon cable is peeled away from the conductor layer at the end of the cable. The backing is glued to the reverse side of the PC board edge to relieve the strain on the conductor connections. I can't tell for sure if the ribbon conductors are soldered to the board. The protective backing makes me think the conductor traces are self adhesive and the backing has to be removed to attach the conductors to their corresponding pads on the PC board.

Does this sound like the kind of ribbon cable you repaired? Could you give me a general idea of what you did to repair yours? I can supply a picture if necessary.

Thanks

Reply to
Techguy

Do a search for zebra connector for more info.

Reply to
Homer J Simpson

I'm familiar with a foam Zebra strip which is several millimeters thick. I've never seen that material used to make a ribbon cable. The ribbon cable in question is made with two thin layers of plastic film sandwiched together. One inner surface has the conductor traces and the other is the protective layer over the conductors. The cable is less than 1-mm thick.

Reply to
Techguy

IME rubber zebra strips - haven't seen foam. However it is a fact that some processes are not doable in the field and it is possible that this is one.

Reply to
Homer J Simpson

this is why I stick with the old vacuum flourescent microwaves. work great. :)

Reply to
Mike

Yep. I like my all tube VCR and Ipod also!

Reply to
Homer J Simpson

formatting link

Reply to
Techguy

formatting link

Love it!

--
++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Required crap appended to avoid restrictions imposed by brain   +
 Click to see the full signature
Reply to
Homer J Simpson

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.