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Old 24th Jun 2022, 5:21 pm   #1
agardiner
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Default Sony ICF-2001 help

Hi,

I hope someone can assist with a fault that is driving me mad on a Sony ICF-2001 radio.

When received it was dead, and I tracked the fault and fixed it. I also had to fit a replacement speaker. Works very well indeed on all bands.

However - it has a very strange behaviour. When you switch the power off, the display remains on. When you then turn the set back on, there appears to be no action, although the radio is drawing power. Tuning the set immediately restores normal operation. This makes sense, as being the the primitive micro is still on, the radio hasn't received the tuning information.

When in the fault state, the sleep button doesn't work, so its clear that the micro doesn't know the radio has been switched off.

Note - this fault is actually intermittant, sometimes the radio works perfectly.

I have already replaced one of the dreadful ribbon cables from the DA board to the micro/lcd board, and also the ribbon from the main signal board to the DA board. Both replacements initially seemed to fix the problem, only for it to return. Likewise, I have had the power switch out, the external power jack socket out, cleaned both, the pins, pcb etc and reflowed. Again, seemed to fix it, then the fault suddenly returns.

Does anyone have experience of such a problem who can point me in the right direction?

Thanks,

Adrian.
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Old 24th Jun 2022, 6:37 pm   #2
Lloyd 1985
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Default Re: Sony ICF-2001 help

Hi,
Has the radio suffered an battery leakage before? I ask as the one I have, which was the subject of a repair thread on here, had suffered, and what I found was that a lot of the plates through hole connections were rotten, so it would be worth checking continuity against the circuit diagram of any tracks from the power switch to the micro, one might be high resistance. You can fix the plated holes simply with either a bit of wire stuck through it and soldered each end, or cheat and use conductive silver paint! It could be an intermittent power switch, mine was rotten internally, you can swap it with the tuning encoder lock/ speed switch, as it’s the same type.

Regards
Lloyd
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Old 24th Jun 2022, 6:44 pm   #3
ParcGwyn
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Default Re: Sony ICF-2001 help

Hi,

I am following this, my Sony ICF-2001 has the same fault. I purchased it a car boot sale for £3, the seller had tried to replace a faulty speaker and damaged the ribbon cables and on/off switch. I cannot see how the on/off switch lever should be held in position, I assume there should be a spring. Mine shows no signs of corrosion and performs very well.

Regards

Dave
GW7ONS
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Old 24th Jun 2022, 7:14 pm   #4
agardiner
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Default Re: Sony ICF-2001 help

Hi Lloyd,

No battery leakage at all. And I should add that I have attended to the battery connections on the PCB as I know they can go a bit intermittant.

I have had the power switch out and it tests 100%. Could it still be the cause?
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Old 24th Jun 2022, 7:27 pm   #5
Cruisin Marine
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Default Re: Sony ICF-2001 help

I has similar problems, not a Sony, from distant memory maybe a Saisho, there was crud on the keypad, maybe some liquid had been spilt on the key press pads, cleaned them and all was ok.
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Old 24th Jun 2022, 7:55 pm   #6
agardiner
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Default Re: Sony ICF-2001 help

Thanks but not that. Keyboard is miniature switches.
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Old 24th Jun 2022, 8:00 pm   #7
Cruisin Marine
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Default Re: Sony ICF-2001 help

Thanks but not that. Keyboard is miniature switches.

Switches can play up just as much, not achieving a true (or stable) logic low or high if contaminated.
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Old 24th Jun 2022, 9:31 pm   #8
Goldieoldie
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Default Re: Sony ICF-2001 help

Is it the original 2001 or the later 2001D ?
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Old 24th Jun 2022, 10:30 pm   #9
PJL
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Default Re: Sony ICF-2001 help

This is the model with the crazy design of steel springs that connect power from the batteries to the PCB. Have you hard wired the battery connections as poor connections can cause all sorts of issues?
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Old 24th Jun 2022, 10:33 pm   #10
Goldieoldie
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Default Re: Sony ICF-2001 help

As well as hard wiring the main batteries also hard wire the memory battery ( 2 x AA cells )
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Old 25th Jun 2022, 8:30 am   #11
agardiner
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Default Re: Sony ICF-2001 help

Original 2001. Yes, thanks Goldieoldie, I was aware of the springs issue and have already attended to this.

Its an odd one - can't actually be the power switch, as the radio does turn off. One side of the switch provides a ground path for the switching transistor; radio goes off, B+ is turned off correctly, and current draw drops to zero. The micro however thinks the set is running, and the display stays on. Power MUST be reaching the micro OK, or it couldn't do this. Removing either of the power sources, (main or 2AA backup) causes the display to go out.

This set has had far too long on the bench chasing this particular fault. I might re-wire the main power switch to actually 'switch' the main power rail. Although a mod, it would at least cure this issue.

Every suggestion is welcome, and no suggestion is ever silly as simple things can be overlooked. But I suspect that this is one of those faults that unless you have had and successfully found, then it is going to go be elusive!
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Old 25th Jun 2022, 11:05 am   #12
agardiner
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Default Re: Sony ICF-2001 help

OK, resolved. I say resolved rather than fixed, as corrected the problem with a small mod.

Main power is switched by Q27. The main battery positive is connected to the emitter, with the collector providing B+. The base is switched via R90 to ground via the on/off switch. The main positive rail is also connected via one of the ribbons through the DA board to the micro. This appears to only be used by the micro as a 'battery present' line. There is a convenient jumper wire on the main PCB near Q27 (connected to the emitter) which feeds this power. I removed the jumper and reconnected the line to the collector of Q27 instead; thus the micro's 4.5V sense line is now switched with the main power. The result is a complete cure and the radio works great. Memory is still retained as the 2AA backup is still present.

The only feature you lose by doing this is the 'sleep' function, as the micro thinks the batteries are missing when you switch the power off, so doesn't enable sleep.
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