Manhattan Rx with a dead Power Supply

[FTAaddict]

Hello to all members,
I'm a newbie here but not new to the satellite hobby, I actually live in the USA but thought that I could get some better help from you pros, I've read many of the posts here and see that you are a bunch of great people.

I can't find any help here in the USA for these Manhattan Rx's, they aren't very popular here. Anyway, I was hoping somebody could help me figure out whats wrong with a dead PS in my Manhattan Skyline 1000, I know it's an oldie but it's a goodie to me, I hate to see it end up as a door stopper. LOL

I don't have a lot of experience in electronics but enough knowledge to do the hands-on work if I can get the right guidance. I suspect a bad cap from what I've read in my research. I actually have 2 of these 1000 models so I swapped in the other PS to make sure the mainboard is working and it does work.

I took voltage readings on all voltage taps and they all average about half of what they should be, this leads me to believe the LARGE cap ahead of the transformer may be the problem (Samwha 400V 47uf), I haven't checked it yet with any meter, I just ordered a Digital Capacitance Meter but I won't have it for another week. I also have a VOM and know how to use it.

My question for you gents is; has any of you had any experience with a Skyline 1000 power failure and can offer any suggestions or guidance in how I should approach the repair? I've never checked a cap before and could use your help.

Thanks to you all

 

[HB13DISH]

Hello FTAaddict,

Recently I had a problem with my Nokia 9800S receiver and I also suspected the power supply and ended up replacing an electrolytic capacitor with an alternate and the box was alive again.
And it was a 400V 47uF, just like what you are suspecting.
See this thread
http://www.satellites.co.uk/satellite/digital-systems/110919-nokia-9800s-problem.html

I don't think that you will need a capacitance meter. Just order a capacitor with the same ratings (105C) and same lead spacing.
Look for incriminating signs like leakage of electrolyte and if any component looks brownish in colour or if they look like they are about to explode.
It would be easier for you since you have two power supplies and it is easier to compare between the good one and the faulty one.
The problem might be something else, but the capacitors are the prime suspects.
You will need a soldering iron and a piece of solder, if you can find them from last time.
Good luck

 

[FTAaddict]

Hello FTAaddict,

Recently I had a problem with my Nokia 9800S receiver and I also suspected the power supply and ended up replacing an electrolytic capacitor with an alternate and the box was alive again.
And it was a 400V 47uF, just like what you are suspecting.
See this thread
http://www.satellites.co.uk/satellite/digital-systems/110919-nokia-9800s-problem.html

I don't think that you will need a capacitance meter. Just order a capacitor with the same ratings (105C) and same lead spacing.
Look for incriminating signs like leakage of electrolyte and if any component looks brownish in colour or if they look like they are about to explode.
It would be easier for you since you have two power supplies and it is easier to compare between the good one and the faulty one.
The problem might be something else, but the capacitors are the prime suspects.
You will need a soldering iron and a piece of solder, if you can find them from last time.
Good luck

Thank you much my friend, I read all of the posts in your thread and found it quite interesting and informative too. At least my Manhattan doesn't have security screws,

I suspected the same cap as your's and so I will consider it first, once I get my Digital Capacitance Meter then I can accurately check it, all of the components appear normal, visually.

The strange thing is, I didn't have much luck a few days ago when I did a search for a vendor of that cap here in the USA, I found a lot of caps with the same uF rating but they were rated with a lower or higher voltage, there was one listed that was rated at 450V 47uF and a larger size canister with a wider lead spacing. I assume that a higher voltage rating of 450V should work OK. May I ask where you found the Nichicon cap? I would imagine you got it somewhere in the UK and not the USA.

I'll search further for one here in the USA and see if I have any luck.

Thanks again for your quick reply and I'll be back to let you know how it goes or if I have more questions. Cheers to you all

 

[HB13DISH]

Thank you much my friend, I read all of the posts in your thread and found it quite interesting and informative too. At least my Manhattan doesn't have security screws,

I suspected the same cap as your's and so I will consider it first, once I get my Digital Capacitance Meter then I can accurately check it, all of the components appear normal, visually.

The strange thing is, I didn't have much luck a few days ago when I did a search for a vendor of that cap here in the USA, I found a lot of caps with the same uF rating but they were rated with a lower or higher voltage, there was one listed that was rated at 450V 47uF and a larger size canister with a wider lead spacing. I assume that a higher voltage rating of 450V should work OK. May I ask where you found the Nichicon cap? I would imagine you got it somewhere in the UK and not the USA.

I'll search further for one here in the USA and see if I have any luck.

Thanks again for your quick reply and I'll be back to let you know how it goes or if I have more questions. Cheers to you all

Hi again,

I found the capacitor in a local shop. This is a standard cap so you shouldn't have any problem getting it.
Try Digikey or Mouser, although buying one or two units might be rather costly.
The important thing is the lead spacing and the height.
Let me know if you can't find it and I will send you by post as a gift. Hopefully the shop still have it.

 

[FTAaddict]

Hi again,

I found the capacitor in a local shop. This is a standard cap so you shouldn't have any problem getting it.
Try Digikey or Mouser, although buying one or two units might be rather costly.
The important thing is the lead spacing and the height.
Let me know if you can't find it and I will send you by post as a gift. Hopefully the shop still have it.

Wow! You are a blessing! I just might ask for the gift offer, I've been searching for the last 2 hours and so far found only information and a part number that has the exact dimensions and values. This is the part number that I came up with, it says that it has a blue outer cover;
Nichicon part# UBT2G470MHD This part number is for their high temp model and there are other ones as well at lower temp and life expectancy that will work as well but I didn't write down those part numbers.

I will certainly let you know what I find in my search for a source.
Please keep your eye on me, I really appreciate all of your help and generosity. Well, back to my search. Cheers!

 

[HB13DISH]

No problem. Just try to get the lead spacing and height.
We have a storm coming up today and the next few days, but early next week I can go to the shop if by then you can't find it.

 

[HB13DISH]

OK. Check this part from Digikey

UVZ2G470MHD

_http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=493-1451-ND

It has 7.5mm lead spacing, 105C 971 ea. in stock at $ 1.61 Series VZ

Good Luck.

 

[FTAaddict]

OK. Check this part from Digikey

UVZ2G470MHD

_http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=493-1451-ND

It has 7.5mm lead spacing, 105C 971 ea. in stock at $ 1.61 Series VZ

Good Luck.

Great job my friend, I checked Mouser and every single 400v 47uF cap is backordered, then I looked at Digi-Key and I guess I didn't search correctly, I couldn't find one that I thought would work, it's quite confusing when they have so many variables and series types.

So I followed the link you gave me and I ordered one just now, I'll see just what happens with this baby once I install it.

Thank you very much for all your help and I'll talk to you later.

 

[PaulR]

Does Radioshack still exist in the USA? The UK arm (Tandy) folded some years ago so I'm not sure. Anyway, didn't they sell components?

 

[FTAaddict]

Does Radioshack still exist in the USA? The UK arm (Tandy) folded some years ago so I'm not sure. Anyway, didn't they sell components?

Hi, Yes they still exist but I don't know how, LOL
We have one about 10 miles away but they don't stock more than batteries, cell phones and electric tape if you know what I mean.... They didn't even know what RG6 coax cable was.

 

[HB13DISH]

Great job my friend, I checked Mouser and every single 400v 47uF cap is backordered, then I looked at Digi-Key and I guess I didn't search correctly, I couldn't find one that I thought would work, it's quite confusing when they have so many variables and series types.

So I followed the link you gave me and I ordered one just now, I'll see just what happens with this baby once I install it.

Thank you very much for all your help and I'll talk to you later.

Ok. Good.
Let's hope that this is the only part that is causing the problem.
Just remember that the capacitor is polarized, so make a note of where the negative and positive leads should be inserted and then solder it to the PCB.
Good Luck.

 

[FTAaddict]

Ok. Good.
Let's hope that this is the only part that is causing the problem.
Just remember that the capacitor is polarized, so make a note of where the negative and positive leads should be inserted and then solder it to the PCB.
Good Luck.

OK thanks, I noticed they are polarized, luckily the PCB is marked, it has good documentation of the voltages and symbols, it makes it easier to work with. I'm hoping that it's the actual part and only part that is defective. I'll let you know how it goes. Cheers!

 

[FTAaddict]

Ok. Good.
Let's hope that this is the only part that is causing the problem.
Just remember that the capacitor is polarized, so make a note of where the negative and positive leads should be inserted and then solder it to the PCB.
Good Luck.

Hello my friend's,

I haven't received the new 400v 47uF cap replacement yet that I ordered but I did get a DCM and I measured 45.1uF on this cap, is this sufficient or is it considered a low reading to warrant replacement? Should I continue checking other components? What do you recommend?

Thanks to you all.

 

[Llew]

Hi there

Electrolytics have a wide capacitance range. Expect at least a 20% plus or minus reading.

More to the point, you can't go by the capacitance reading alone on a suspect electrolytic. The series resistance can increase due to stress in a power supply, and it loses its ability to work efficiently after a time even if it's still holding to its capacitance value.

Best to bin and replace with a new one.

Llew

 

[FTAaddict]

Hi there

Electrolytics have a wide capacitance range. Expect at least a 20% plus or minus reading.

More to the point, you can't go by the capacitance reading alone on a suspect electrolytic. The series resistance can increase due to stress in a power supply, and it loses its ability to work efficiently after a time even if it's still holding to its capacitance value.

Best to bin and replace with a new one.

Llew

Thanks for your advice , I thought the same and I will try the new cap when I get it. Have a great day my friend!

 

[HB13DISH]

I also agree with Llew about replacing the cap with the new one.
But there is still a chance that the problem is somewhere else. Diode rectifiers, inductive parts, etc.
If the replacement doesn't help much, please take some good photos of the power supply and post here as attachments. This might help us to identify other potential suspects.
And this is where the fun really starts.

 

[FTAaddict]

Hello friend's, I did install the new cap and I still have the same exact problem, no change whatsoever. Here are photos and also a chart of the voltage readings. I'll be doing some studies on electronics while you fellows are thinking this over. Thanks in advance for all your help, you guys are the coolest!

 

[Llew]

As the PS is outputting voltages, at least the primary side is working. I would concentrate on the secondary side filter capacitors, those in pic 7.

Different SMPSs react differently to no load conditions, which you were in when you took those voltage readings. Some go into overvoltage mode and shut down or 'trip'. As it's running and you have at least (low) voltages on the outputs, the only suggestion I can offer without having a schematic of the PS is to start substituting the electrolytics in pic 7; first one should be the one that supplies the 5V output.

Llew

 

[HB13DISH]

Hello friend's, I did install the new cap and I still have the same exact problem, no change whatsoever. Here are photos and also a chart of the voltage readings. I'll be doing some studies on electronics while you fellows are thinking this over. Thanks in advance for all your help, you guys are the coolest!

Hello again FTAaddict,

Thanks for the update and the excellent photos.

Sorry that the problem is still there, but looking at the components used, they all seem to be quite cheap to replace. So all you need is a lot of patience.
You have a big advantage since you have another PS and you can compare measurements between the two units at various stages and hopefully you will hit on the problem.
By the way, since you are from the states where the mains voltage is 110V, I was just wondering if your box was originally bought in Europe and if you are using an adapter or if it was purchased in the USA and is suited to 110V directly.
Good Luck.

 

[FTAaddict]

As the PS is outputting voltages, at least the primary side is working. I would concentrate on the secondary side filter capacitors, those in pic 7.

Different SMPSs react differently to no load conditions, which you were in when you took those voltage readings. Some go into overvoltage mode and shut down or 'trip'. As it's running and you have at least (low) voltages on the outputs, the only suggestion I can offer without having a schematic of the PS is to start substituting the electrolytics in pic 7; first one should be the one that supplies the 5V output.

Llew

Thanks Llew for the great help, looks like I'll have to dig deeper. I did document the readings with the PS connected to the mainboard but neglected to post them, they are still fairly consistant in the low range.

Hello again FTAaddict,

Thanks for the update and the excellent photos.

Sorry that the problem is still there, but looking at the components used, they all seem to be quite cheap to replace. So all you need is a lot of patience.
You have a big advantage since you have another PS and you can compare measurements between the two units at various stages and hopefully you will hit on the problem.
By the way, since you are from the states where the mains voltage is 110V, I was just wondering if your box was originally bought in Europe and if you are using an adapter or if it was purchased in the USA and is suited to 110V directly.
Good Luck.

Hi HB13DISH, I thank you too, unfortunately I gave my other receiver to my friend who is using it now, I'd hate to deprive him of TV but the good thing is that I have documented the readings which should help in the diagnosis.

These receivers were purchased here in the US and have the 110vac cord, I did notice that the PCB has another plug near the 110vac plug that might be for UK use.

Anyway, as you said it will take some time and patience, I have them both. I'll let you know how it goes, it might take me a while . Thanks to you all for such great support. I'll be back Until then, Cheers!