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  1. kellys_eye

    PCB mounted transformer How to identify?

    The only way it could cause a 'short' like that is if your meter was in a high current measuring mode - it may also happen in a low resistance mode (but why would you be measuring resistance on a 'live' board?) Maybe the probe tips don't have sufficient insulation? All told it shows a little...
  2. kellys_eye

    Computer mouse circuit repair

    You will need to remove the resist (black 'paint') to expose any copper to solder to. The connection may be on the other side of the board too.
  3. kellys_eye

    Question about 16x2 LCD Displays failing.

    May be via fixed resistors off board - the contrast is on pin 3 of the LCD edge connector (usually - pin 1 is nearest the short edge of the board) but if the 5V supply has 'wandered' then this can affect the contrast too. Check that the 5V supply is within tolerance. Be mindful of the fact...
  4. kellys_eye

    Help Identifying blown component

    Ouch! - those two electrolytic capacitors look SEVERELY 'blown' - change them and FAST! It could be that ZD9 is in fact a NTC thermistor (surge suppressor) of 100 ohms....
  5. kellys_eye

    Question about 16x2 LCD Displays failing.

    That just looks like a level of poor 'contrast' to me - there should be a small trim pot to adjust it. That may make a difference. But 1602 displays are 10-a-penny figuratively and the one you have fitted seems to have the bog standard connection i.e. the 14 terminals at the bottom left so...
  6. kellys_eye

    Solar Immersion Controller - Noise Issues

    Does the device have the (usual) ferrite suppressor on its mains lead/wires? Whether it does or not, you could try adding an extra ferrite and maybe a couple of turns of the individual (live and neutral) wires over some and see if that improves matters. Otherwise I'd be on to the manufacturers...
  7. kellys_eye

    PCB mounted transformer How to identify?

    What did you do to cause the short on the link wire? TBH I wouldn't advise you to do anything else to this board. Your lack of knowledge/skill to work on this type of board could be dangerous to yourself, potentially others too. Have a look for a spare board on eBay - you might find it...
  8. kellys_eye

    PCB mounted transformer How to identify?

    The only board we're interested in is the PSU - the rest of the pictures are of no use. We might also need to see the reverse of that board too - they sometimes mount parts on the rear..... Save yourself some trouble...
  9. kellys_eye

    Noisy Otari MX5050 BII-2 Tape deck

    No, disconnect the signal path (break it). You could short that point to ground to prevent stray pickup at the input point but for the higher level sections this isn't strictly necessary. But since the noise is present on both channels you must approach this from a common point - either the...
  10. kellys_eye

    Boxes. Cases. I need simple coverings for my projects! What do you use?

    In years gone past I've even put a PC into a wooden bread box...... looked great!
  11. kellys_eye

    Noisy Otari MX5050 BII-2 Tape deck

    Break the audio path at strategic locations to isolate the relevant sections (PA, preamp, pre-emphasis etc). Is it both channels? If so then the common denominator is the PSU.
  12. kellys_eye

    Noisy Otari MX5050 BII-2 Tape deck

    Have you checked the heads?
  13. kellys_eye

    Total Electronics Novice In Need Of Power Supply Advice

    Such adapter usually have a thermal fuse wound into the transformer and when it goes 'open' it renders the adapter totally useless (unless you have the skills to dismantle/repair them). Wise decision to stop using it. 12V 1500mA is fine (same as 1.5A) and, as you already know, the modem will...
  14. kellys_eye

    Short/open circuit detector in wall

    Same here - but the faults, if any, will be at the socket plates (not withstanding anyone drilling holes or putting screws in them). Our own installation safety instructions (UK) show the position of cable runs and it would be unusual for someone to drill or screw into a cable - basically avoid...
  15. kellys_eye

    125 degree C electrolytics by Su'scon

    Lots of nasty bulging capacitors on that board! There's no rhyme or reason behind them using 125C versions as the temperature will be pretty much the same for all of them in the area so if they've used 105C versions elsewhere you may as well use them everywhere.
  16. kellys_eye

    Short/open circuit detector in wall

    opens and shorts are rarely anywhere except at either end of the cable. If you have a problem, check at the outlet and at the fusebox. The chances of a short/open anywhere inbetween (unless there is a hidden junction box) are as good as zero.
  17. kellys_eye

    Noisy Otari MX5050 BII-2 Tape deck

    I find it difficult to read that schematic but can see that VR501 and VR502 set the oscillator levels.
  18. kellys_eye

    125 degree C electrolytics by Su'scon

    I wouldn't bother - 105oC should be more than sufficient.
  19. kellys_eye

    Noisy Otari MX5050 BII-2 Tape deck

    ...that might be useful if it was posted here!
  20. kellys_eye

    Component wanted

    Not sure where you'll get one but a few things to note: 1. it's a 4-bit digital step attenuator 2. what makes you think it's broken?
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