GE Blockbuster power supply issue

[Matrixambience]

Anybody have the knowledge or expertise on zeroing in on power supply issue with my newly acquired GE 3-5259A boombox that maybe relegated to the parts junkyard pile?
I spent $250 plus on it on eBay knowing it had issues but this one is kicking me !
I power it up, and the power led light is dim as I add load to it, whether turning volume knob up or trying to use cassette player functionality.
I have belt off tape deck main spools and motor spindle. Motor spins, but I can stop motor with my fingers on spindle pulley and then motor doesn’t spin or is weak and spins slowly.
Is it a weak motor or the power supply transformer? Also as I turn up volume it makes a clipping sound as I add load. Thanks to anyone who can help.

 

[hopey]

Try with DC Supply or batteries and see if problem still exists.

 

[BoxBeats]

When I had discovered that I had a bad motor I had watched a youtube video on the Blockbuster (Spats Bear is the channel:

) that he had a power issue that I had thought might have been the issue. He replaced a resistor which I did as well. It wasn’t my issue but maybe.

 

[BoxBeats]

Don’t give up, there are nice people here. The Blockbuster is awesome, someone will help.

 

[hopey]

Sounds like you may have bad insulation in a switch try to isolate the reed switches for the tape deck.

 

[Matrixambience]

When I had discovered that I had a bad motor I had watched a youtube video on the Blockbuster (Spats Bear is the channel:

) that he had a power issue that I had thought might have been the issue. He replaced a resistor which I did as well. It wasn’t my issue but maybe.

Thanks! I watched this video already and very informative. I think I’m leaning towards the power transformer board and transformer.

 

[Matrixambience]

Try with DC Supply or batteries and see if problem still exists.

Good idea. I will put in 8 D cells in to see if it’s transformer or not.

 

[docs]

I have seen this happen with similar symptoms, turned out to be a) little swutch in power socket and b) the actual power switch.
Soak with contact cleaner and work thoroughly while unpowered.
Retest and see if there is any change in the symptoms, even just slightly.

 

[Matrixambience]

I have seen this happen with similar symptoms, turned out to be a) little swutch in power socket and b) the actual power switch.
Soak with contact cleaner and work thoroughly while unpowered.
Retest and see if there is any change in the symptoms, even just slightly.

Thanks! I will try that also. I even tried another power cord to see if it changed, and it didn’t. There is a transformer and power board where cord goes in on eBay right now and it’s for the Realistic SCR8, which is sister model to GE. I may buy it and see if that is culprit. I don’t have the test equipment to check voltage and all that stuff. I’m flying blind here…..

 

[docs]

While open just soak in contact cleaner on the switch where the cable plugs in and then do the same on the power button. At least eliminate these two before moving on.

 

[BoxBeats]

This PDF book has helped me in various situations with my Blockbuster: https://www.dropbox.com/s/1fqhjlppq...ing and Repair Handbook ( PDFDrive ).pdf?dl=0

 

[BoxBeats]

It is a consumer repair book that has chapters on Boomboxes. Here is the link.Download PDF

 

[Tinman]

I don’t have the test equipment to check voltage and all that stuff. I’m flying blind here…..

You really are.
You should think about buying an auto-ranging multimeter.
It's the most basic equipment you need to troubleshoot electrical issues.

 

[Superduper]

This is how I would approach it. First you need to determine if the system voltage is being dragged down. You can do this by checking system voltage with unit running. If voltage drops precipitously with added load, then you need to know whether this is due to reduced capacity of the PS or due to excessive voltage drop through the system. Check voltage directly at the transformer outputs and repeat. If voltage is dropping there, then you know that the issue is in the power supply section. If the voltage remains constant, then you'd have to look further. Dirty power switch could be the issue, as could it be the AC/DC switch. If the issue is within the PS itself, then most likely that can be addressed as well but it might be too involved for me to describe the process here given your skill level. I would start with those 2 switches. If you don't even have a meter, or know how to use it, then the only thing you can do is clean those switches and if that doesn't do it, you'd have to get it serviced. I might be able to help you, but you should try those first.

 

[Matrixambience]

This is how I would approach it. First you need to determine if the system voltage is being dragged down. You can do this by checking system voltage with unit running. If voltage drops precipitously with added load, then you need to know whether this is due to reduced capacity of the PS or due to excessive voltage drop through the system. Check voltage directly at the transformer outputs and repeat. If voltage is dropping there, then you know that the issue is in the power supply section. If the voltage remains constant, then you'd have to look further. Dirty power switch could be the issue, as could it be the AC/DC switch. If the issue is within the PS itself, then most likely that can be addressed as well but it might be too involved for me to describe the process here given your skill level. I would start with those 2 switches. If you don't even have a meter, or know how to use it, then the only thing you can do is clean those switches and if that doesn't do it, you'd have to get it serviced. I might be able to help you, but you should try those first.

Thanks! Okay good points and great processing to eliminating ideas. I tried the contact cleaning in the main power button on/off and also used it in the power cord female end in unit, and no changes. I seriously believe the cassette player had someone spilled in it or something. I did my best to clean the whole cassette player and reapplied phono lube to all parts and gears that require lube. Also, the motor is weak.

 

[Matrixambience]

You really are.
You should think about buying an auto-ranging multimeter.
It's the most basic equipment you need to troubleshoot electrical issues.

Owning one is one thing…… knowing how to use it is my main concern. So many variables with electrical power.

 

[Tinman]

Owning one is one thing…… knowing how to use it is my main concern. So many variables with electrical power.

The auto-ranging multimeter is fairly easy to use and you can find the basics online (YouTube has lots of tutorials).
It could pay for itself if it helps you track down this problem.

 

[Matrixambience]

The auto-ranging multimeter is fairly easy to use and you can find the basics online (YouTube has lots of tutorials).
It could pay for itself if it helps you track down this problem.

Thanks. I have new Mabuchi motor coming to me soon. It’s NOS and exact as original. I hope that is the main culprit.
Next thing would be transformer/ AC cord power board combo. There is one on eBay for $30 from a Realistic scr8, sister radio to GE. Maybe buy that and have it as spare part.