You were supposed to measure the resistance across four resistors. If the resistors were still conducting there should have been no voltage across the resistor. If this analysis is correct then it would suggest that the resistor is blown open-circuit.

It is my fault for not asking you to discharged the power supply capacitors. I suppose you will have to do this any and every time you are measuring resistance.

I am happy to take this as far as we wish.

 

Ok. Thanks I appreciate it. I will continue tomorrow. Too many errand to run today. I will get with you tomorrow.

 

LEFT === RIGHT
R7547 = 11.7 meg. ohm R7548 = OL(open?)
R7549 = 46.2 k ohm R7550 =220.7 ohms

Same readings in both directions, red and black leads switched.

 

LEFT === RIGHT
R7547 = 11.7 meg. ohm R7548 = OL(open?)
R7549 = 46.2 k ohm R7550 =220.7 ohms

Same readings in both directions, red and black leads switched.

Get and install replacements for
R7547
R7548
R7549

all 220 ohms
I cannot tell the wattage and size of the SMD from the photo. Size 0805 0.25W 1% might be a good place to start.

It helps to have two soldering irons to assist in removing SMD resistors and capacitors (or a soldering iron with a special 2-pronged tip).

Don't buy just 3. Get a minimum of 10.
You may want to stock up on other parts (fuses, transistors, etc.) to justify the cost of shipping.

Before you place an order, let's confirm the status of the diodes D7519-D7526 and transistors Q7503-Q7510.
Check resistors R7537-R7540.

Maybe it wouldn't hurt to purchase these as well.

 

Any particular place to order the parts?

 

Where did you purchase your NTE transistors?

My goto for semiconductor components are Digikey, Newark and Mouser.
Check and compare prices, stock and shipping charges. Watch price breaks for larger quantities.
When you find the one with all stock and best deal, buy all from the one distributor to spread out the shipping charges. If you can hit their minimum for free shipping, so much the better.

Since I do a fair amount of R&D and repairs I always buy more than what I need and keep stock. Since I have over 10,000 components I have to maintain a computerized database otherwise I would never be able to find my components.

 

Understood. Looks like the service manual has a parts list. I'll spend the morning trying to find the parts. Most of them seem to be at Mouser. Found the SMDs on Amazon. Since I am not R&D or even a repairman, would it be prudent to get some stuff from Amazon with quick free shipping?

Trying to find the tweezer soldering iron for the SMD removal.

 

Bought the NTEs locally. I am going to get all original replacements for the output transistors. Won't reinstall the NTEs.

 

I would not trust NTE transistors for this application. These are generic transistors with an NTE stamp on it.
I would recommend buying the transistors from one of the three houses I listed.
Resistors are a dime a dozen hence there is nothing to gain by buying it from Amazon.

 

Ok. Will do.

 

Measured resistors R7537-R7540. All 10 ohms, as indicated on the schematic.
Diodes D-7519-26--No readings on D7526 ;D7524 seems to be shorted, Reading 0.0 using diode setting on multimeter.
All others, .566 reading in current flow direction and 0.0 (OL) reverse direction.

Do I do resistance or power measurements on the transistors Q7503, Q7509, Q7504 ,Q7510?

 

I have both transistors in stock. Contact me offline if you need them

Dan

 

Had already ordered all parts. Thanks though.

 

I can't seem to find the correct transistors for Q7213 and Q7216. I ordered from Digi-Key but got the wrong SOT-23. These are only 2.9 mm wide. ZThe ones on the board are a little larger. Not sure what case it is. Thought it was SOT-3.

 

I have both transistors in stock. Contact me offline if you need them

Dan

Dan, do you have the 2SC2859 and 2SA1182 original Toshiba? I need four of each at least. ZReally only need two each, but like to have a couple spares.

Also 8 of the SMD chip transistor Pioneer part number RSI/108220F 220 ohm.

 

I am having difficulty finding switching diodes Part #s 1SS244 and HH104-02. Does anyone know of equivalent replacements or where I can find these. Mouser and DigiKey don't stock. Nor does Arrow. Appreciate your help.