Philips PM 5509 I /06 TV PAL Pattern Generator - UK Vintage Radio Repair and Restoration Discussion Forum

flyingtech55 · 4th Nov 2008, 1:14 pm

Hi all

Just rescued one of these from the scrap pile. Problem is it doesn't work properly which is why it was being thrown away.

Certain functions of it work but mainly the colour bars are incorrect. The most obvious symptom though is that the regulator on the topmost PCB is getting very hot...and I mean hot. The area of PCB to which the regulator is bolted is charred to a deep brown and the heat sink is too hot to touch. It will actually burn you if you leave your finger on it for more than a few nano-seconds. Hence, I didn't leave it on long enough to fully investigate which functions work and which don't.

The questions are:

1) Is this a common fault on these and if so what is the cure.
2) Do any forum members have experience of repairing these.
3) Does anyone have the manual for this unit.

Any pointers would be much appreciated. I don't have any great experience of repairing test equipment. It contains a whole bunch of TTL type chips. I have been told that the +5V rail de-couplers associated with these TTL chip populated PCBs are prone to going leaky and causing this type of problem. Alternatively, there are a number of largish smoothing capacitors on the PCB next to the regulators and one of these may be leaky.

As I say, any pointers would be appreciated.

timR

Brian R Pateman · 4th Nov 2008, 1:27 pm

Leaky de-couplers is the most likely problem. The 5V supply is fairly heavily loaded if I recall correctly. I don't know if I have a manual for this but I'll have a look when I get home this evening.

Regards,

KeithsTV · 4th Nov 2008, 1:31 pm

Hi Tim

As a quick check measure the supply on the TTL ICs usually pin 7 = 0v & pin 14 = 5v (14 pin devices) or pin 8 = 0v & pin 16 = 5v on 16 pin devices. This should be between 4.75v & 5.25v. I suspect from what you have said that it will be low due to either a faulty decoupling cap or a faulty IC.

Keith

Studio263 · 4th Nov 2008, 5:24 pm

My one of these had a fair few faults, all of which were down to the smallest type of electrolytic capacitor that you find in there. Change the lot before getting too involved.

Brian R Pateman · 4th Nov 2008, 11:00 pm

Hello Tim,

I only have the manual for the 5506 / 5508. I think that they may be similar and if you send me your E-mail address in a PM I will gladly send it to you.

Having said that I think that if you change the capacitors as suggested here you will probably get it to work.

Regards,

flyingtech55 · 5th Nov 2008, 12:49 pm

Hi Brian

Thanks to you and the other chaps for your replies. What I'll do is check the voltage and loading of the +5v regulator. If it is, as suspected, being excessively loaded I'll load shed until I narrow down the cause and correct it.

I'll then see if the unit works properly. If so I'll renew the overloaded regulator in the interests of future reliability and put in unit into use. If not, I'll get back to you Brian if I may and borrow your manual and delve deeper.

TimR

4th Nov 2008, 1:14 pm	#1
flyingtech55 Octode Join Date: Nov 2005 Location: Ayrshire, UK. Posts: 1,096	Philips PM 5509 I /06 TV PAL Pattern Generator Hi all Just rescued one of these from the scrap pile. Problem is it doesn't work properly which is why it was being thrown away. Certain functions of it work but mainly the colour bars are incorrect. The most obvious symptom though is that the regulator on the topmost PCB is getting very hot...and I mean hot. The area of PCB to which the regulator is bolted is charred to a deep brown and the heat sink is too hot to touch. It will actually burn you if you leave your finger on it for more than a few nano-seconds. Hence, I didn't leave it on long enough to fully investigate which functions work and which don't. The questions are: 1) Is this a common fault on these and if so what is the cure. 2) Do any forum members have experience of repairing these. 3) Does anyone have the manual for this unit. Any pointers would be much appreciated. I don't have any great experience of repairing test equipment. It contains a whole bunch of TTL type chips. I have been told that the +5V rail de-couplers associated with these TTL chip populated PCBs are prone to going leaky and causing this type of problem. Alternatively, there are a number of largish smoothing capacitors on the PCB next to the regulators and one of these may be leaky. As I say, any pointers would be appreciated. timR __________________ All those moments will be lost in time, like tears in rain.

4th Nov 2008, 1:27 pm	#2
Brian R Pateman Nonode Join Date: Jun 2005 Location: Western Lake District, Cumbria (CA20) - UK Posts: 2,136	Re: Philips PM 5509 I /06 TV PAL Pattern Generator Leaky de-couplers is the most likely problem. The 5V supply is fairly heavily loaded if I recall correctly. I don't know if I have a manual for this but I'll have a look when I get home this evening. Regards, __________________ Brian

4th Nov 2008, 1:31 pm	#3
KeithsTV Nonode Join Date: Aug 2007 Location: South Bradford, West Yorkshire, UK. Posts: 2,573	Re: Philips PM 5509 I /06 TV PAL Pattern Generator Hi Tim As a quick check measure the supply on the TTL ICs usually pin 7 = 0v & pin 14 = 5v (14 pin devices) or pin 8 = 0v & pin 16 = 5v on 16 pin devices. This should be between 4.75v & 5.25v. I suspect from what you have said that it will be low due to either a faulty decoupling cap or a faulty IC. Keith

4th Nov 2008, 5:24 pm	#4
Studio263 Octode Join Date: Apr 2007 Location: Hampshire, UK. Posts: 1,577	Re: Philips PM 5509 I /06 TV PAL Pattern Generator My one of these had a fair few faults, all of which were down to the smallest type of electrolytic capacitor that you find in there. Change the lot before getting too involved.

4th Nov 2008, 11:00 pm	#5
Brian R Pateman Nonode Join Date: Jun 2005 Location: Western Lake District, Cumbria (CA20) - UK Posts: 2,136	Re: Philips PM 5509 I /06 TV PAL Pattern Generator Hello Tim, I only have the manual for the 5506 / 5508. I think that they may be similar and if you send me your E-mail address in a PM I will gladly send it to you. Having said that I think that if you change the capacitors as suggested here you will probably get it to work. Regards, __________________ Brian

5th Nov 2008, 12:49 pm	#6
flyingtech55 Octode Join Date: Nov 2005 Location: Ayrshire, UK. Posts: 1,096	Re: Philips PM 5509 I /06 TV PAL Pattern Generator Hi Brian Thanks to you and the other chaps for your replies. What I'll do is check the voltage and loading of the +5v regulator. If it is, as suspected, being excessively loaded I'll load shed until I narrow down the cause and correct it. I'll then see if the unit works properly. If so I'll renew the overloaded regulator in the interests of future reliability and put in unit into use. If not, I'll get back to you Brian if I may and borrow your manual and delve deeper. TimR __________________ All those moments will be lost in time, like tears in rain.