- WANTED: used/defective Sharp microwave control panels (R15## & R140# models preferred) - 1 Update
- MOV I.D. Help please - 1 Update
- how to repair this circuit board? - 3 Updates
| Ken Hill <caedfaa9ed1216d60ef78a6f660f5f85_14866@example.com>: Feb 04 01:44PM replying to Sharp Guy, Ken Hill wrote: Hi, I need the control panel if you think it works. My buttons fell off. -- for full context, visit https://www.homeownershub.com/maintenance/re-wanted-used-defective-sharp-microwave-control-panels-r-890473-.htm |
| pbzcbfzragvf@gmail.com: Feb 03 05:10PM -0800 See page 13. http://www.grandpas-shack.com/parts/datasheets/ENB(FUJI).pdf The last 2 digit are a lot number. The part number suffix is related to the diameter of the disc. ENB401D-10A -> 13mm ENB401D-14A -> 17mm ENB401D-20A -> 24mm |
| three_jeeps <jjhudak@gmail.com>: Feb 03 09:17AM -0800 On Sunday, February 2, 2020 at 8:32:25 AM UTC-5, John-Del wrote: > If done properly, the cracks will be barely visible. Scrape the green mask off the trace just at the break and half the distance the trace is wide. A drop of solder across each land will finish it. > In your case, because the pieces don't fit that well, scrape back the mask and hand wire from point to point and across the fracture with some fine copper stranded wire (one or more strands depending on width of the trace), and coat the entire trace with solder using the copper strand as a sort of "rebar". > Deflux the board and apply either a conformal coating or get some green nail polish to protect the lands. "In your case, because the pieces don't fit that well, scrape back the mask and hand wire from point to point and across the fracture with some fine copper stranded wire (one or more strands depending on width of the trace), and coat the entire trace with solder using the copper strand as a sort of "rebar". " This is exactly what I would recommend. For small traces, 22awg or 24awg copper wire would work fine. For larger traces that carry more power, add two or three strands of wire instead of 1 strand. Not sure of the board mounting arrangement, or how much stress the board may be subject to, but, I'd suggest you consider applying a board stiffener along each side of the board. the stiffener could be wood/plastic and could be screwed (#4 machine screw?) or epoxied in place. If you mount with screws, make sure the holes do not short copper traces. Nylon screws should work well. This is a general recommendation. An exact spec would be based on seeing the board and mounting arrangement. |
| John Robertson <spam@flippers.com>: Feb 03 10:11AM -0800 On 2020/02/03 9:17 a.m., three_jeeps wrote: > "In your case, because the pieces don't fit that well, scrape back the mask and hand wire from point to point and across the fracture with some fine copper stranded wire (one or more strands depending on width of the trace), and coat the entire trace with solder using the copper strand as a sort of "rebar"." > This is exactly what I would recommend. For small traces, 22awg or 24awg copper wire would work fine. For larger traces that carry more power, add two or three strands of wire instead of 1 strand. Not sure of the board mounting arrangement, or how much stress the board may be subject to, but, I'd suggest you consider applying a board stiffener along each side of the board. the stiffener could be wood/plastic and could be screwed (#4 machine screw?) or epoxied in place. If you mount with screws, make sure the holes do not short copper traces. Nylon screws should work well. > This is a general recommendation. An exact spec would be based on seeing the board and mounting arrangement. I agree with the above repairs - we have done similar with other HV Xformers PCBs successfully that have lasted for many years. This PC Board was broken either by stress from the weight of the flyback or bad handling if the board was not mounted. Perhaps rough handling during a move or the monitor was dropped a foot or so to a floor... To reduce the risk of future fractures make sure the weight of the HV transformer/flyback is properly supported otherwise it will break again. Take care that HV route between the switching transistor and Xformer are kept clear of any potentially (yeah, I know) conductive material when you are supporting it - as it sees back EMF of up to 1500VDC. Other HV traces also need to be kept isolated from the supports. Note that any added supports can accumulate dust over the coming years and that this dust can provide a conductive path... John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| Tempestinatesttube <tempest@ina.com>: Feb 03 07:54PM -0500 I picked up some desoldering braid and used that across the broken traces. I was careful to first scrape away any coatings with a flat blade screw driver. After maybe 20 min of work, all of the gaps were bridged and time to test. Once plugged in and switched on, whola! All working again. Thanks for the group's help. Lots of helpful suggestions. I really didn't know if it would work even after doing all this as it had arrived that way through the mail, and the person I got it from sent it parcel post with no insurance and in a single flimsy box. About the worst way anyone could send fragile electronics. However, it is working again and I am happy. I do want to add supports across the ends of the board horizontally for more strength, but otherwise I think it's all good now. By the way, some of you might want to check JB Weld's website. Only certain of their epoxies are conductive and others are not. The one I used (JB Quick Weld) was not. Just FYI. Thanks again! |
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