KENWOOD KA-701 POWERS ON, NO RELAY CLICK

[rccrasher65]

I think I got it see if these help I can get better now that I know what I'm doing.

[petehall347]

be very careful with those bias diodes that are screwed to the heat sink .the wires tend to break off right next to the body and are hard to find new ones and also not easy to fix .

[CapLeaker]

I see some saaad looking resistors that are crispy. Those caps near that heat sink should be changed out too...

[petehall347]

yep it needs a good old looking at and any substitute transistors carefully selecting

[rccrasher65]

be very careful with those bias diodes that are screwed to the heat sink .the wires tend to break off right next to the body and are hard to find new ones and also not easy to fix .

Can you circle what you are talking about, thanks

[rccrasher65]

I see some saaad looking resistors that are crispy. Those caps near that heat sink should be changed out too...

Can you highlight what resistors look bad, I plan on replacing, most of the components on that board anyway.

[petehall347]

Can you circle what you are talking about, thanks

these things

[CapLeaker]

Can you highlight what resistors look bad, I plan on replacing, most of the components on that board anyway.

Here!

[rccrasher65]

Can you highlight what resistors look bad, I plan on replacing, most of the components on that board anyway.

Yea,I saw those, actually they test good, but are getting replaced anyway. Thanks. Some parts are coming on Wed, this week.

[rccrasher65]

these things

Thanks, I thought that's what you were talking about. There will be no need to touch them at all.

[rccrasher65]

Here!

some transistors are arriving today! I'm going to start with the 4 big output trans. first then Q11, Q10, ect. I'm going to place an order for some new resistors, as well as new caps.

[rccrasher65]

Most of my parts will arrive on Friday, I'm going to start with Q11, 10, 9 ect first, then the smaller transistors, followed by the caps on the board. For the 4 big output Transistors ,can I use arctic silver 5 thermal compound? Also, any secrets loosening the transistor screws in a tight space. 50 yrs old original never touched.

[CapLeaker]

You may take the transistors with the heatsink out. Then change the transistors on the heatsink and put the new mounted transistors with the heat sink back in. Always mount the transistors first before soldering, otherwise you risk damage. I suggest you clean and replace all old thermal paste on everything that is mounted on a heat sink, as the original paste is 50 years old and hard as a rock. Use 99% alcohol to clean the thermal paste.

[petehall347]

can I use arctic silver 5 thermal compound? .

get some proper white stuff for the job . all that arctic silver stuff is not right for amplifiers

[rccrasher65]

You may take the transistors with the heatsink out. Then change the transistors on the heatsink and put the new mounted transistors with the heat sink back in. Always mount the transistors first before soldering, otherwise you risk damage. I suggest you clean and replace all old thermal paste on everything that is mounted on a heat sink, as the original paste is 50 years old and hard as a rock. Use 99% alcohol to clean the thermal paste.

Thanks, for the advice. So it's best to remove the whole heat sink from the unit first, then remove old transistors, replace old compound with new, and place new transistors on heat sink. I'll order some white thermal compound too.

[rccrasher65]

You may take the transistors with the heatsink out. Then change the transistors on the heatsink and put the new mounted transistors with the heat sink back in. Always mount the transistors first before soldering, otherwise you risk damage. I suggest you clean and replace all old thermal paste on everything that is mounted on a heat sink, as the original paste is 50 years old and hard as a rock. Use 99% alcohol to clean the thermal paste.

Ok, I'll give that a try, will need to order white thermal compound. THANKS

[CapLeaker]

You can leave the transistors on the heatsink, you just have to desolder them first from the PCB. Then pull the heat sink with the transistors attached off the board. The important thing is you mount the transistors with the thermal paste to the heatsink first. Then solder.

[rccrasher65]

You can leave the transistors on the heatsink, you just have to desolder them first from the PCB. Then pull the heat sink with the transistors attached off the board. The important thing is you mount the transistors with the thermal paste to the heatsink first. Then solder.

Sounds good, I got them, one screw head was a little jacked up, but it came out. I'm still stumped on one diode, it's the zener diode XZ-100, kenwood part number is V11-4104-10. I have found really no answere for a replacement, just guessing it could be a 10v, not really sure, hoping someone could give it a shot in finding out an equivalent. Looking foreward to my parts all arriving on friday and Mon, at the latest.

[petehall347]

Sounds good, I got them, one screw head was a little jacked up, but it came out. I'm still stumped on one diode, it's the zener diode XZ-100, kenwood part number is V11-4104-10. I have found really no answere for a replacement, just guessing it could be a 10v, not really sure, hoping someone could give it a shot in finding out an equivalent. Looking foreward to my parts all arriving on friday and Mon, at the latest.

d9 d10 is it ? remove one and use resistor and 2x 9v batteries and volt meter .

[CapLeaker]

These XZxxx zeners are a bit weird numbered. For example a XZ051 equals a 5.1V zener. It is NOT a 51V zener.
So what you are looking at is a XZ100 zener. That makes it a 10V. Check it out like petehall347 said above.