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  1. dorke

    Problem - Tuner amp AKAI AA 1175

    Mike, The schematics show only 2 fuses on the inputs of the receiver. In the UK, for 240V,(according to the schematics) they should be 3.15A each. Can you please post some photos of the fuse locations? A TV repair shop isn't the place to go for that job, you need someone who repairs vintage...
  2. dorke

    T8 - LED shop lighting

    How much do you pay for those LED T8s? With incandescent type LED replacement (probably true for T8) I have seen LED bulbs add the spec for on/off cycle times. For home use, this would make the bulb life much less than the LED life itself! Anyways , the 50,000 number is for the LEDs only, not...
  3. dorke

    A christmas conundrum

    Here is something to reflect upon:
  4. dorke

    Help with a connector (Newb Question)

    Here is another issue you have to deal with: This looks like a mid 80s product. In that time there were a few different types of LCD driver controller IC chips,they were not compatible. Today there is a Defacto industry standard which is compatible to the Hitachi HD44780 LCD display driver...
  5. dorke

    Dial cord slipping

    As strange as it sounds,it dose look like there is no switch related to any pot in the schematics ,wouldn't expect this kind of slip from Philips. In this case you have to trace the wires and find out how and where it is connected.o_O Not very complicated,it's a relatively simple beast.;) And...
  6. dorke

    Dial cord slipping

    What a beauty, with a magic eye too:) If you are lucky,you may be able to fix that pot. In case it is the kind that can be opened easily and if the carbon inside it is intact. I did in the past.
  7. dorke

    Problem - Tuner amp AKAI AA 1175

    Well, Do you have a DMM and know how to use it? Do you know how to solder and did that before? If the answer to the 2 above is a definite yes,we can help you with the repair,otherwise you need someone else to do it for you. In #1 you said "The lights are on as usual",if you refer to the dial...
  8. dorke

    help -- muh logic ended in ruins

    Welcome to EP. In short: CMOS means Complementary MOS and that you have done, but the name lacks the most important term,the NMOS/PMOS pair should be a well matched pair. You can't get that with discrete TO-92 style,since the transistors are not on the same die. So yes,using the CD4007 will...
  9. dorke

    Not sure to be safe or sorry

    Try sorting them before grouping them, do that In terms of current and brightness. You can use a 3.3V power supply and measure current. If you don't have one use a small 3v battery (even a coin one may do the trick for you). As noted above,don't parallel LEDs use them in series.
  10. dorke

    What's this called (knob attachment)

    "Locking knob",with/without a tightening screw on the side
  11. dorke

    Dial cord slipping

    Well, 1st thing , verify that the string works freely without entangling (the turns should be parallel to each other and remain so while you move the tuning knob) in the tuning drum and the shaft. 2nd thing, verify that all the plastic wheels turn freely. 3rd thing, In most cases there are 3...
  12. dorke

    MCS 3847 Integrated Amp Noisy Left Channel

    O.K. So this unit most probably doesn't have the Volume pot just before the P.A(like most do). In this case it is clear that the tone control section , which follows the volume pot , may also be a possible source for the noise. In order to verify which board is the source of the noise, I would...
  13. dorke

    MCS 3847 Integrated Amp Noisy Left Channel

    Well, The "guides" for old/vintage audio restoration would say "replace all electrolytic capacitors",needed or not,that doesn't usually solve problems,it is more of a preventative thing. No, I don't think it is a power issue simply because most power is common to both channels. Some of the...
  14. dorke

    Finding a nano amp transistor for Solar LED Light Marker

    Audioguru , A "solette" is a nickname for a small part of a solar cell/panel. A "joule thief" can be made with a Germanium transistor(like this one) it will work well below 0.5V input voltage. The idea was not to have a constantly lit LED at night but to pulse it on/off at a ratio of 1:200...
  15. dorke

    Is using term "BaudRate" correct when talking about SPI?

    Welcome to EP. The terms are used interchangeably. The term "Baud Rate" should be understood to be the number of Symbols per second ). In a "binary system communication" the number of symbols per a single time interval is 2. Thus the bit-rate and the baud-rate are the same. The more appropriate...
  16. dorke

    Finding a nano amp transistor for Solar LED Light Marker

    I think a joule-thief charger circuit may be helpful here. Use it to charge your battery at day light time(boost the solette voltage). Than the circuit in #1(with the same solette to control the LED activation at dark) may be used. It is worth testing the following approach for the LED...
  17. dorke

    MCS 3847 Integrated Amp Noisy Left Channel

    Well, Please measure (with volume knob at minimum !!!) the DC voltages relative to chassis GND on the 5 pins Trs Tr202 vs. Tr201 without disturbing anything. Start with Tr202(the good channel). While measuring, listen to the noise,if it disappears when you touch something,it is important to note...
  18. dorke

    MCS 3847 Integrated Amp Noisy Left Channel

    I would rather catch that noise,and pin point it. But looking at the bottom side of the board the area of the bad channel looks much dirtier than that of the good one. All that dirt should be removed with rubbing alcohol and cotton buds. Cleaning alone can cause the noise to vanish for good...
  19. dorke

    MCS 3847 Integrated Amp Noisy Left Channel

    @73's de Edd , I don't think the problem is before the P.A board since the O.P has already checked what you have written at #18 And specifically, the noise is there with Volume pot. at minimum. He can re-check everything ,but I would expect no results from that. @KilgoreCemetery , In regard to...
  20. dorke

    Guitar Pickup Winder

    Welcome to Ep. You need to see this.Simple and very effective. Adding a counter is simple, like this or you can make an optical "fork like " opto- cupler counter. Or like this hope that helps ;)
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