Sony ICF-200W Handheld Transistor Radio Issues

[jr_tech]

On low power devices, a bad electrolytic does not necessarily bulge because there is simply not enough power to heat up a shorted one enough to bulge. You may indeed have some shorted or open capacitors in the circuit, regardless of appearance.
But the first order of business is to clean off the battery connectors and check for voltage on the board, as mentioned above. Power switches often fail on these sets, so check for voltage on either side of the switch while turning it on and off.
Do you then hear a click/pop in the speaker when you operate the switch, or any scratch noises as you operate the volume control?

jr

[Captainclock]

Originally Posted by jr_tech

On low power devices, a bad electrolytic does not necessarily bulge because there is simply not enough power to heat up a shorted one enough to bulge. You may indeed have some shorted or open capacitors in the circuit, regardless of appearance.
But the first order of business is to clean off the battery connectors and check for voltage on the board, as mentioned above. Power switches often fail on these sets, so check for voltage on either side of the switch while turning it on and off.
Do you then hear a click/pop in the speaker when you operate the switch, or any scratch noises as you operate the volume control?

jr

I do not hear a popping noise through the speaker or a scratching noise through the speaker as the volume is rasied it is completely dead silent regardless of what I do with the power/volume switch.

I did clean most of the corrosion off of the battery terminals that I could and I still don't get anything.

Edit: Recleaned the terminals and reflowed the solder on the terminals on the terminal boards and I tested at the terminals with batteries installed and unit powered on, and I'm still getting nothing, tested at terminals with batteries installed and unit powered on with voltmeter and I get 1.5 volts at each terminal on the back side of the terminals, but then when I test at where the wires from the terminals go on the main circuit board with the unit powered on I only get a 1/3 of a volt and when the unit is powered off and I test at the place where the battery terminals connect to the main board I get 1.5 volts (there should be 4.5 volts there because that's all 3 of the batteries combined flowing into those wires.) Do I perhaps have a bad battery or something? I bought a package of batteries brand new from the store and I would of thought that they were all good but then again I bought generic batteries so who knows.

[jr_tech]

Originally Posted by Captainclock

I'm still getting nothing, tested at terminals with batteries installed and unit powered on with voltmeter and I get 1.5 volts at each terminal on the back side of the terminals, but then when I test at where the wires from the terminals go on the main circuit board with the unit powered on I only get a 1/3 of a volt and when the unit is powered off and I test at the place where the battery terminals connect to the main board I get 1.5 volts (there should be 4.5 volts there because that's all 3 of the batteries combined flowing into those wires.)

Sometimes the corrosive chemicals from the leaky battery "wick" into the wires connected to the battery terminals and eat away the copper conductor... the wire may look ok from the outside but may high resistance. Suggest an ohm meter check of the wires to the board (remove batteries first, of course).

jr

[zeno]

1)Unhook or unplug the battery box from the radio.
If soldered in one lead is fine.
2) measure volts. If 4.5 V the batteries & holder OK.
If not then the problem is the holder or bats.
3) If the voltage drops a lot when you hook up
the radio something is loading things down. Look
at the output IC or transistors first.
The radio may have crapped out then got tossed in a drawer
& the bats leaked......

If you like working on small stuff ( I do !) get some DC
output wall warts. They used to make them with a voltage
switch ( 4.5 - 12 V ), multi connectors & polarity switch.
ADD a pair of wires with alligator clips that are color coded
& you can sub it in to any low current device without
batteries involved. As for bats I only use duracells from a
known source to avoid Chi-Com junk & counterfits.

73 Zeno

[Captainclock]

Originally Posted by zeno

1)Unhook or unplug the battery box from the radio.
If soldered in one lead is fine.
2) measure volts. If 4.5 V the batteries & holder OK.
If not then the problem is the holder or bats.
3) If the voltage drops a lot when you hook up
the radio something is loading things down. Look
at the output IC or transistors first.
The radio may have crapped out then got tossed in a drawer
& the bats leaked......

If you like working on small stuff ( I do !) get some DC
output wall warts. They used to make them with a voltage
switch ( 4.5 - 12 V ), multi connectors & polarity switch.
ADD a pair of wires with alligator clips that are color coded
& you can sub it in to any low current device without
batteries involved. As for bats I only use duracells from a
known source to avoid Chi-Com junk & counterfits.

73 Zeno

The batteries I bought were the generic store brand batteries (they were almost 50% less than the Duracells price wise for the same amount of batteries, and I've bought store brand batteries in the past and never had any issues with them.) I used to have a switchable voltage AC Adaptor but it took a dump on me a while ago (it was one I had gotten from radio shack several years before they went through bankruptcy and when they still had a decent selection of electronics parts yet in store.)

[maxhifi]

Originally Posted by zeno

1)Unhook or unplug the battery box from the radio.
If soldered in one lead is fine.
2) measure volts. If 4.5 V the batteries & holder OK.
If not then the problem is the holder or bats.
3) If the voltage drops a lot when you hook up
the radio something is loading things down. Look
at the output IC or transistors first.
The radio may have crapped out then got tossed in a drawer
& the bats leaked......

If you like working on small stuff ( I do !) get some DC
output wall warts. They used to make them with a voltage
switch ( 4.5 - 12 V ), multi connectors & polarity switch.
ADD a pair of wires with alligator clips that are color coded
& you can sub it in to any low current device without
batteries involved. As for bats I only use duracells from a
known source to avoid Chi-Com junk & counterfits.

73 Zeno

I have a couple EICO 0-30V 0-500mA variable power supplies which are awesome for this kind of work. Keep eyes open for one, they work amazingly well and aren't worth much money.