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View Full Version : help damaged C548 on underside of mother board tryingto replace caps


robotman
12-05-17, 13:36
as stated above any one know what this components value is and if a there a way of replacing with something easier as it was my poor soldering skills that caused this bloody shakes
any advice or should i bin it
cheers Rob
adm
12-05-17, 13:39
as stated above any one know what this components value is and if a there a way of replacing with something easier as it was my poor soldering skills that caused this bloody shakes
any advice or should i bin it
cheers Rob

Can you supply a picture of the damage?

Is it a surface mount component?
robotman
12-05-17, 14:03
Can you supply a picture of the damage?

Is it a surface mount component?

yes i managed to catch it when i slipped trying to solder for some reason it keeps failing to up load the photo
roybach
12-05-17, 16:03
Could it be that the file size you are attempting to upload is to big ? I'm not sure but there might be a limit on the file size you are allowed to upload.
adm
13-05-17, 08:15
yes i managed to catch it when i slipped trying to solder for some reason it keeps failing to up load the photo

Without a circuit diagram or reading the value from the device (probably a 3 digit number) its almost impossible to establish the value.

However, if its close to an electrolytic capacitor (the type you are replacing) then it MAY just be a generic decoupling capacitor and it could be replace with a common value surface mount capacitor or a capacitor with leads. A photo may have given a clue to how the circuit board tracks from this capacitor are routed to other components.

Using a magnifying lens is there a 3 digit number printed on the the device?
If you can, try again with photos - perhaps two, one showing a general view and one closer up.

If you remove the capacitor completely does the box still work. A removed power decoupling capacitor is unlikely to have much effect (or no effect) on normal operation?

Advice: Never use lead free solder on this type of repair/capacitor replacement. Lead free solder can be the spawn of the devil.
Use tin/lead solder 60%/40% with flux core as used for decades before the "greenies" without any technical knowledge started making legislation.
Example


https://www.rapidonline.com/rapid-60-40-tin-lead-flux-cored-solder-wire-30236

(smaller amount/cheaper for a one off repair available from many Ebay sellers)
I recommend re-soldering the connections BEFORE trying to remove the component. The flux that helps the solder flow is washed off during manufacture. Re-soldering the joint adds some flux from the new solder and makes it easier to remove the component an/or to use a solder sucker or solder wick


If, AND IT'S A BIG IF, it is a decoupling capacitor something like this may be OK


https://www.rapidonline.com/suntan-ts170r2a104ksbba0r-0-1uf-10-100v-x7r-2-54mm-radial-ceramic-capacitor-11-3442

It's not surface mount but for someone not used to soldering surface mount components the leads can be bent to meet the pads on the board and soldered.

WITHOUT MORE INFORMATION this last part is pure speculation!
robotman
15-05-17, 01:03
Thanks for the info I'm still trying to get the photos to upload. I'll get there ,but I think my soldering days are over seem to do more damage these day's. Replaced all the usual suspect capacitors mainly concerned with the low signal issue and then neat'nd up my previous red light repair while I had the main board out .now I wish I had used the easy method and cut the capacitor off the board and soldered it on without taking the board out .oh well lesson learned.
Time for a new box.
Can anyone recommend something that won't require capacitors needing replacement as often or is this common place with most receivers.
I still own a tm9100 that had a capacitor replaced years n year's ago and its still working fortunately. Thank god its all I've got at the moment .
roybach
15-05-17, 19:08
You could consider one of the newer sat boxes that use an external power supply similar to the ones used with Laptop computers , never had a problem with this type of power supply and the Sat box runs cooler as well, which may go some way towards reliability. an email or phone call to W.o.S should give you a choice of what is available that suits your pocket.