Close-Ups Of The Sharp GF-9595H!

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Ghettoboom767

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May 6, 2009
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Hi-I have a weak power supply but want to check for sure,
Where do I check and I'm for 99% for sure on this as the radio gets somewhat distorted as the volume goes up and espesially the cassette-it slows way down as you increase the volume,
What capacitors do i replace on the Power supply board?
Also what Capacitance-the same as what's on there?
Anyone have a way of circling the parts in the photo or helping me on this?
I also need a voltage selector wheel & or the the wires and maybe the transformer as that looks a little burnt,?
Anyone have these extra?

It all works but especailly when you run the tape deck the power goes way down-like the power on lights and stereo light will go out when you go up on the volume so it's definately a power supply issue.
Again I need help where to test for voltage(sorry no capacitor tester!)Only voltage/ohm meter.
I'd really like to ge this beast running better-the power supply will fix most everything but maybe my spindle not being perfectly smooth.
Needs a newer capstan spindle.
This thing is a breeze to work on,comes apart real nicely.
Any help would be appreciated.
Thanks-GB. :-O :yes: :hmmm:


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Ghettoboom767

Member (SA)
May 6, 2009
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Hi guys-could anyone here help me??
I would appreciate it!
Anyone have a parts box for me for this model?
Thanks-Jeff. :-O :hmmm:
 

Prime

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May 6, 2009
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My first guess would be the voltage selector/transformer area. If not wired correctly or not at all, which seems to be what you have, then the transformer may be running in 220/240V mode while on 120V mains which would give you the low voltage symptoms you have described.

If you can solder the correct color wires back to the voltage selector you may be ok unless they were cut for a reason. Maybe the transformer was already replaced from being burnt up running on 220 while set to 120 ??
 

Ghettoboom767

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May 6, 2009
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Prime said:
My first guess would be the voltage selector/transformer area. If not wired correctly or not at all, which seems to be what you have, then the transformer may be running in 220/240V mode while on 120V mains which would give you the low voltage symptoms you have described.

If you can solder the correct color wires back to the voltage selector you may be ok unless they were cut for a reason. Maybe the transformer was already replaced from being burnt up running on 220 while set to 120 ??

Hi Prime-I'm looking into getting parts like the voltage wheel and the transformer maybe to.
There was some burnt area on the plastic near the wires off the voltage wheel so maybe it's bad?.
I got this from Henrytai for cheap but it just needs some work.
I can wire all this stuff in but need a new voltage wheel for sure to start.
Need to check outputs on this transformer-doing this next and seeing if the wheel even works!
I'll let you know.
Thanks Brett I appreciate it.
This will be a nice box when I get this fixed and the capstan shaft replaced.
There's a somewhat of a parts box on e-bay but the guy wants 169.00-a little high since it hardly works but may be worth it if it's still around in a couple of weeks.
Have a great one-GB. :-D
 

Superduper

Member (SA)
Forget the voltage wheel. Just bypass it and be done with it. Unless you are going to sell it back overseas, it shouldn't matter as we don't use 220 here in the states.

As for checking the supply, it's simple. Hook up a voltmeter at the output from the power supply and verify voltage while you operate. It should remain constant which would indicate that the supply is adequate. Also, check to make sure all connections are good. Resolder if you have to.

The capacitors you'll want to start with are the large filter capacitors. Those would typically be the largest ones. Replace those if you think that they might be putting a drain on system power.
 

Ghettoboom767

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May 6, 2009
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Superduper said:
Forget the voltage wheel. Just bypass it and be done with it. Unless you are going to sell it back overseas, it shouldn't matter as we don't use 220 here in the states.

As for checking the supply, it's simple. Hook up a voltmeter at the output from the power supply and verify voltage while you operate. It should remain constant which would indicate that the supply is adequate. Also, check to make sure all connections are good. Resolder if you have to.

The capacitors you'll want to start with are the large filter capacitors. Those would typically be the largest ones. Replace those if you think that they might be putting a drain on system power.
Thank-You Superduper!!!!
I'm testing this thing tonight when I have some time.
I was thinking that the voltage wheel has been already by-passed for the reason that it was probably bad.
I'll be replacing the large caps on this but do you know how much a cheap capacitor tester is?
I'd maybe like to test the few that I'm going to replace.
This boombox still has life in it.
The cassette is easy-I can replace the whole spindle /capstan shaft if I find another,also my rewind cog is worn out.
This are easy to replace.
It's just the power supply needs help and i plan on testing this thing further tonight.
Once again-I'm very happy Superduper to assist me on this.
The GF-9595H is a real "bomb".
I like the all digital display-Rad!
Have a great one-Jeff.GB. :-) :yes:
 

Superduper

Member (SA)
Leaky filter capacitors can put a drain on the system. Forget about buying a cheap capacitor testor. The only thing a cheap one is going to tell you is the approximate uf rating. It won't tell you the ESR, or how much leakage there is. A good one sufficient for testing is available from Sencore such as LCR-75, LCR-101, LCR-102 but they cost in the hundreds for a good used one. You should test them out of circuit anyhow because the tester will apply AC voltage to the capacitor and testing it in circuit (1) won't be accurate and (2) the voltage could damage other components. The point is that once you have them out of circuit, you might as well replace them since capacitors aren't all that expensive. After 25-30 years, they are all suspect anyhow.

The reason I'm asking you to check the voltage is because if it's low, it's the source of all your problems. Normally, on multivoltage systems, the transformer has several input leads which will translate to a certain output voltage. If the voltage wheel has already been bypassed and is hooked up so that the box is expecting 220volts, then voltage will be very low. However, if the voltage at the power supply is OK, then you may be looking at other issues.
 

Ghettoboom767

Member (SA)
May 6, 2009
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Thanks Superduper-I think it's at 110(at least that's where it last said position).
I'll keep you informed.
I went into this exrtensively on the "other' site about a year ago when I got it but just have lulled it out lately.
Could you tell me how many of the large caps should I replace?
I'm thinking as many on the power suplly board as I can but I'll let you know some voltage outputs after tonight.
Thanks again-GB. :-)
 

Prime

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May 6, 2009
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Lets not get ahead of ourselves here. Hold off on pulling out any caps until you find out
what the voltage is across the large cap next to the four diodes. This model takes 8 D cells
so the voltage across the cap should be around 12-14 volts for all operating conditions.
If its considerably less, one of the following could be the cause.

a. the transformer is incorrectly wired for 120v.
b. one of the four rectifying diodes is "open".
c. a leaky cap.
d. the voltage is being pulled down somewhere else downstream.

Also, if the voltage seems low, put your hand on the transformer after
the unit has been on for a while. It should be a little warm. A hot transformer
would imply that the transformer working correctly but something else, like a leaky/bad cap
is working against it, pulling the voltage down.


Tell us your voltage findings and we'll go from there.
 
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