Philips N7300 reel to reel problems

[sowa616]

Hello everyone i have a Philips N7300 reel to reel and I'm having trouble with it.

The small bad part is it powers on ok but switch doesn't catch so will need replacing that i can do . The really bad part however is none of the transport functions work.

So when i hold down the power switch the capstan motor starts running and i can change the speed via The speed selector switch. Thats about as much as i can do.

But i cant get the player to engage the transport functions rww,fwd,play,rec etc none of them work. The motors dont spin nothing completly dead apart from the capstan motor it seems to run all the time.

If anyone could help id much appreciate that i have attached a pdf of the service manuel.

http://www.megaupload.com/?d=QFFZU4LR

Please note i brought this as faulty off ebay.

 

[goldear]

Have you tried this with tape, or without tape? If you are trying this without tape, have you done anything to trick the tape sensors so that the transport will actually engage?

 

[sowa616]

Have you tried this with tape, or without tape? If you are trying this without tape, have you done anything to trick the tape sensors so that the transport will actually engage?

ive done this with and without tape but no luck the guy who i brought it off did say the transport functions were not working. and when he got it at a boot sale as faulty and he had no luck fixing it do to limted knowedelge and time so im hoping i can fix it and follow in his steps.

is it worth replacing all the ic's as im not shure looking at the shematics what ic or transistors i may need to replace to be fair theres not many compared to other tape decks ive come across?

 

[goldear]

You need to put tape into the machine to make sure that some tape sensor is not keeping the transport from running, if you don't know how to fool the sensors on this machine. R2Rs are not supposed to run when they don't have tape loaded, so what you have described sounds like normal behavior so far.

 

[eclectik]

is it worth replacing all the ic's as im not shure looking at the shematics what ic or transistors i may need to replace

If it won't work with the tape correctly threaded, don't waste your time, you clearly do not have the skills or experienece required. Do yourself a favour and TAKE it to a tech before you wreck it. These machines are not for the faint hearted, being later and rarer Philips. Parts are far harder to find than for, say, Revox.

In fact, I seem to remember you being the guy who used a gas soldering iron on a Pioneeer 707 on a different forum...Please do not destroy another decent bit of kit with hamfisted 'repairs'!

 

[koltrast]

These have a complicated mechanism for engaging the pinch roller, made of plastic and prone to breaking. The bad power switch is also a common problem.

 

[sowa616]

If it won't work with the tape correctly threaded, don't waste your time, you clearly do not have the skills or experienece required. Do yourself a favour and TAKE it to a tech before you wreck it. These machines are not for the faint hearted, being later and rarer Philips. Parts are far harder to find than for, say, Revox.

In fact, I seem to remember you being the guy who used a gas soldering iron on a Pioneeer 707 on a different forum...Please do not destroy another decent bit of kit with hamfisted 'repairs'!

that wasnt me mate you got me mistaken for someone else. but thats easy to say now try telling me somone you know who can fix these machines and charge a reasonable price.

no i didnt think so thats why i invested in it and also because i want to learn more about how these machines work. im not stupid i can solder and i can read schematics its just hard to tell yet weather i got a electrical problem or a mechnical problem.

 

[sowa616]

You need to put tape into the machine to make sure that some tape sensor is not keeping the transport from running, if you don't know how to fool the sensors on this machine. R2Rs are not supposed to run when they don't have tape loaded, so what you have described sounds like normal behavior so far.

the tape is thread correctly.

 

[dr*audio]

I'll take a look at the schematic later. For now here is some guidance. If you can read a schematic, perhaps you are just a bit overwhelmed by the complexity of the deck.
1. Jumper out the power switch for now so you can work on it.
2. Measure all the power supply voltages. A general failure like this is often caused by a power supply problem. If it has caps in there that say Fraco on them, suspect a power supply problem, as these caps go bad.
3. If the power supply voltages are ok, look at any switches that are activated by the tape guide levers when the levers are in position with a tape loaded. With the power off, measure across the switches with a meter on Ohms and make sure they open / close properly.
Carry on!

 

[sowa616]

I'll take a look at the schematic later. For now here is some guidance. If you can read a schematic, perhaps you are just a bit overwhelmed by the complexity of the deck.
1. Jumper out the power switch for now so you can work on it.
2. Measure all the power supply voltages. A general failure like this is often caused by a power supply problem. If it has caps in there that say Fraco on them, suspect a power supply problem, as these caps go bad.
3. If the power supply voltages are ok, look at any switches that are activated by the tape guide levers when the levers are in position with a tape loaded. With the power off, measure across the switches with a meter on Ohms and make sure they open / close properly.
Carry on!

Ive jumped the power switch for now I'm getting voltages across most of the circuity mainly focusing on the IC's.

 

[dr*audio]

Ive jumped the power switch for now I'm getting voltages across most of the circuity mainly focusing on the IC's.

You have to check the power supply voltages, don't just jump to the IC's. They do go bad, but not as often as transistors, resistors, caps, and solder joints. Those are the main cause of problems.

 

[goldear]

If you are looking for a blanket approach, without any diagnosis of the actual problem, then I would suggest replacing all of the phillips and the Fraco, and WIMA caps. That is more likely to lead to success than is replacing the ICs.

 

[sowa616]

I'm going to check all transistors first theres a good few on the board so might take me some time. once i get all voltages readings off the transistors ill post them up.

 

[pich]

I have an Akai gx625d that wouldn't play when I pressed the play button. I took the button assembly apart, and it's one of those controls that is a printed circuit board with a piece of conductive material on the buttons that shorts the copper traces when you press down. The play and all other functions worked much better after I cleaned the traces.

Not familiar with your Philips deck but maybe it has a similar setup. Good luck.

 

[sowa616]

here is all the transistors voltages Ive taken down using a multi meter. as far as the schematic indicates not all transistors operating voltages are given in the service manual.

TS101

B = 0.6V
C = 5.6V
E = 0.52V

TS1

B = 0.6V
C = 5.6V
E = 0.52V

TS2

B = 5.6V
C = 0.52V
E = 6.2V

TS102

B = 5.6V
C = 0.53V
E = 6.2V

TS9

B = 10.24V
C = 15.39V
E = 10.14V

TS109

B = 10.24V
C = 15.38V
E = 10.15V

TS10

B = 15.39V
C = 9.01V
E = 16.03V

TS110

B = 15.38V
C = 8.89V
E = 16.03V

TS15

B = 26V *4.75cm/25.8V *9.5cm/26.3V *19cm
C = 0V *4.75cm/0V *9.5cm/0V *19cm
E = 26.8V *4.75cm/27.2V *9.5cm/27.4V *19cm

TS16

B = 0V
C = 28V
E = 0V

TS14

B = 27.6V *4.75cm/27.5 *9.5cm/27.9 *19cm
C = 27.8V *4.75cm/27.7 *9.5cm/28V *19cm
E = 27.3V *4.75cm/ 27.3V *9.5cm/27.5V *19cm

TS13

B = 16.72V
C = 17.33V
E = 16.05V

TS6

B = 711mV
C = 8.36V
E = 142.9mV

TS106

B = 701mV
C = 8.65V
E = 135mV

TS7

B = 53.9mV
C = 6.73
E = 590mV

TS107

B = 590mV
C = 6.88V
E = 52.1mV

TS8

B = 616mV
C = 6.11V
E = 3.2mV

TS108

B = 617mV
C = 6.40V
E = 2.9mV

TS3

B = 11.28V
C = 12.76V
E = 10.94V

TS103

B = 11.27V
C = 12.77V
E = 10.92V

TS4

B = 12.76V
C = 7.54V
E = 13.40V

TS104

B = 12.77V
C = 7.61V
E = 13.40V

TS11

B = 568mV
C = 5.88V
E = 0V


TS111

B = 587mV
C = 6.13V
E = 0V

TS12

B = 5.85V
C = 0V
E = 6.52V

TS112

B = 6.10V
C = 0V
E = 6.73V

 

[sowa616]

I'm thinking of investing in replacing all the transistors on the circuit and IC's i mite start with the IC's themselves as there is only a few of them. as its going to take alot of time to figure out whats causing the problem and then ive got peace of mind that the electronic side of things are ok.

 

[dr*audio]

Just one last word of advice.
If you come asking for help and ignore the advice of those who are far more knowledgeble and experienced than you are, and ignore the troubleshooting steps you are told to perform, you will not be getting help from those people again. I asked you to check the power supply voltages, and you didn't. I am not interested in the transistor voltages you measured. You are taking the troubleshooting steps out of sequence instead of proceeding in a logical manner.
I am done with you.

 

[Fisherdude]

I'm thinking of investing in replacing all the transistors on the circuit and IC's i mite start with the IC's themselves as there is only a few of them. as its going to take alot of time to figure out whats causing the problem and then ive got peace of mind that the electronic side of things are ok.

Maybe if you hear the same thing from more than one person you'll listen.

If you don't verify that the power supply voltages are all correct FIRST, then if you check the transistor voltages and they're all WRONG, you won't know if the problem is the power supply or the transistors, and then you'll replace all the transistors and the ICs, and then the voltages might all still be wrong, because it might have been the power supply all along.

First things first.

 

[eclectik]

Just one last word of advice.
If you come asking for help and ignore the advice of those who are far more knowledgeble and experienced than you are, and ignore the troubleshooting steps you are told to perform, you will not be getting help from those people again. I asked you to check the power supply voltages, and you didn't. I am not interested in the transistor voltages you measured. You are taking the troubleshooting steps out of sequence instead of proceeding in a logical manner.
I am done with you.

Don't waste your breath, Warren - this guy is, I'm now convinced, the same chancer who was told the exact same thing on a UK forum about 18 months ago, (and in the process ruined at least two nice reel to reel machines by ignoring advice), and generally wasted everyone's time.

Everyone deserves a second chance, but if this is indeed the same person, the 'second chances' have all been used up!

 

[sowa616]

Just one last word of advice.
If you come asking for help and ignore the advice of those who are far more knowledgeble and experienced than you are, and ignore the troubleshooting steps you are told to perform, you will not be getting help from those people again. I asked you to check the power supply voltages, and you didn't. I am not interested in the transistor voltages you measured. You are taking the troubleshooting steps out of sequence instead of proceeding in a logical manner.
I am done with you.

i have checked the power supply voltages and they all seem fine. im not a complete idiot if thats going to be your attitude ill take my buissness else where as clearly everyone on this forum has it in for me all im trying to do it fix the problem.

with responce to the other guy going on about 2 other players i apprently messed up on some other forum you have the wrong guy i dont know what your going on about!