M90 motor and capacitor question.

[blu_fuz]

There should be one on the top right side facing us in this view.

If there is a burned up resistor i should see something like this:

 

[blu_fuz]

Strange

 

[blu_fuz]

Here is a pic inside the suspect M90 no resistor on this side of the board:




Here is my M90 that looks to have a blown resistor right now:






And while looking in the suspect M90 again, i do see the resistor on the other side of the board and i spotted these cut wires.

 

[blu_fuz]

I soldered the 2 wires back where they should be.

Now when i power on the boombox it makes one click in the deck, and when i turn the box off it makes one click again in the deck.

 

[Superduper]

Wow, this is why restorers that don't know anything about electronics shouldn't be permitted anywhere near the insides if a BOOMBOX, much less a grail. Knowing a little is worse than knowing nothing at all because that's usually just enough to get into and cause big trouble.

Try testing the values of those fusible resistors. The click on power on and off is normal as the controller cycles the deck. The click suggests no or not enough current to complete the task. I'll bet the original motor was probably fine before they yanked it.

 

[blu_fuz]

I agree that it was probably ok before they swapped the motor. Lets just cut the wires lol.

It might take me awhile to find the 4 fusible resistors. The one resistor i did find on the opposite side of the board that my finger was on. Anyone happen to know where the other 3 are?

 

[Superduper]

PM me your email addy and I'll send you a diagram. Can't post attachments with my phone.

 

[blu_fuz]

Got it bud, thank you. The resistors are all next to eachother so thats nice! Ill check tomorrow i hope

 

[blu_fuz]

This might be a dead end for now, only because I need to get this box back to the owner as I have plenty of my own goodies to work on.


Norm, I did find another thread with a lot of information that you posted already:
https://boomboxery.com/forum/index.php/topic/4413-m90-tape-apparently-dea/?hl=%2Bm90+%2Bfusible+%2Bresistor



Here are the specs for the (4) fusible resistors that I could find:

fr-701 & fr-704 = 4.7 ohms 1/4 watts
fr-702 = 10 ohms 1/4 watts
fr-703 = 2.2 ohms 1/4 watts


I'm also going to save the content from the thread I linked above for future reference.