Panasonic Home Cinema... No Power UP

[DIY JONNY]

Hi Guys

I have a Panasonic SA-PT 870 DVD home cinema surround sound...... Wont Power up.
After Checking power lead, fuse, internal fuse....all ok.... I took it to a local repair center.
They said they replaced several components but it needs new power supply pcb... which is no longer available from Panasonic ... so cant be repaired !
Any idea where I might locate the board/s for it ?

There are plenty of 2nd hand units for sale, but not the 870 model... is there any way of telling if they may have the same power boards in.... so i could buy a cheap 2nd hand unit and take the board out.

apparently the part numbers provided by the repair center are CODAAYG00001 and CODAAYH00001 ic power supply.

Worth trying to repair?? or just buy a new reciever unit to power my existing speakers ??
Any help would help.
Thanks... Jonny

 

[Arouse1973]

Hi Jonny
Can you take some pictures of the PCB in question, maybe we will spot something that looks suspect. Nice clear close up pictures are best.
Adam

 

[DIY JONNY]

Hi Jonny
Can you take some pictures of the PCB in question, maybe we will spot something that looks suspect. Nice clear close up pictures are best.
Adam

Hi Adam
I will take some pics and post them later ( if I can sus out how to upload ) but the boards look fine... as in, no burn or scorch marks ... or burn smell....if you know what i mean..... but there is a faint "tick" noise every time I try to switch it on ???

I'm no electrician or electrical engineer... but thought a general tv repair shop could have sorted this by replacing a cap or 2 or perhaps a Mosfet.... they may have tried this..... but surely there will be a replacement board somewhere... I just dont know where to find it.

 

[KrisBlueNZ]

Hi Jonny and welcome to Electronics Point

Those parts are non-isolated switching converter ICs.
C0DAAYH00001, IC2903, takes +18V and produces +5.3V.
C0DAAYG00001, IC2900, takes +18V and produces +9V.

If those are really the faulty components, which remains to be seen, they are probably custom Matsushita components. But you can replace each converter (the IC and the surrounding components) with a pre-built switching power supply module.

Here's the relevant part of the schematic from the service manual:



First you should make sure that they're actually faulty. See whether the +18V rail is present, and whether the +5.3V and +9V rails are missing. If so, you can replace each of those regulator sections with something like http://www.ebay.com/itm/DC-Buck-Ste...978?pt=LH_DefaultDomain_0&hash=item1e936d9fda

 

[Arouse1973]

Hi Jonny and welcome to Electronics Point

Those parts are non-isolated switching converter ICs.
C0DAAYH00001, IC2903, takes +18V and produces +5.3V.
C0DAAYG00001, IC2900, takes +18V and produces +9V.

If those are really the faulty components, which remains to be seen, they are probably custom Matsushita components. But you can replace each converter (the IC and the surrounding components) with a pre-built switching power supply module.

Here's the relevant part of the schematic from the service manual:

View attachment 16963

First you should make sure that they're actually faulty. See whether the +18V rail is present, and whether the +5.3V and +9V rails are missing. If so, you can replace each of those regulator sections with something like http://www.ebay.com/itm/DC-Buck-Ste...978?pt=LH_DefaultDomain_0&hash=item1e936d9fda

Nice one Kris
Adam

 

[Arouse1973]

Buzz these guys an email they might be able to help? Or look at what Kris has recommended.
http://products.pacparts.com/panasonic_c0daayh00001_ic_1102028936.php
Adam

 

[DIY JONNY]

Wow..... you guys are amazing!!!! thanks for your help.... but way over my head...!!
Sounds to me like I've paid £40 for a diagnosis and probably been miss diagnosed..?
If it was case of just unplugging, unscrewing a circuit board and replacing it, like for like, then i think I could manage that, but sounds like without being able to diagnose exactly where the fault is ( I thought thats what i paid for ???) then this could go on and on.
Obviously not an easy fix or the tv repair guy would have fixed it ?
I'm thinking perhaps my best option is to upgrade the dvd receiver perhaps to a newer model or bluray... plenty on ebay.. as the speakers for my existing system are excellent..
Unless Adam lives near Essex and wants to be paid to fix it.... or I fly it to New Zealand to give it to Kris to take a look at... then Im stuck

But thanks again for your help guys.

 

[Arouse1973]

I live in Cornwall, would cost me 50 quid in Petrol just to get there

 

[DIY JONNY]

No Worries Adam.... I have a friend who is an electrical engineer ( Albeit on London underground ) but he will (should) know how to use a tester.
I'll see if he can locate and test the components that Kris pointed out... if they dont seem to be faulty then I will take it back to the repair place.... seems they just took £40, changed a few caps then fobbed me off with a few part numbers that are obsolete.
If the component that Kris pointed out is faulty then the engineer did his job..... and i therefore wont swear at him too much..
Thanks again

 

[KrisBlueNZ]

Sounds to me like I've paid £40 for a diagnosis and probably been miss diagnosed..?

I don't know. I just think you should check the diagnosis.

If it was case of just unplugging, unscrewing a circuit board and replacing it, like for like, then i think I could manage that, but sounds like without being able to diagnose exactly where the fault is ( I thought thats what i paid for ???) then this could go on and on. Obviously not an easy fix or the tv repair guy would have fixed it ?

He probably didn't have the option of hacking in a couple of boards. When I used to work for a repair shop, it was standard practice to replace components with the original part from the manufacturer. No bodgying of non-genuine stuff into the customer's equipment. Of course you have different priorities!

I'm thinking perhaps my best option is to upgrade the dvd receiver perhaps to a newer model or bluray... plenty on ebay.. as the speakers for my existing system are excellent..

Well, if you do, could you send the old one over here? I'll pay for postage! It looks like a pretty impressive piece of kit. Very wanky-swanky. I definitely wouldn't give up on it so easily. Unless you WANT to buy a new one... in which case, PM me and I'll send you my address ;-)

Unless Adam lives near Essex and wants to be paid to fix it.... or I fly it to New Zealand to give it to Kris to take a look at... then Im stuck

Don't be so defeatist! I'm sure you could hack some new boards in there. DIY is in your username, so D I Y!

I have the service manual and can give you step-by-step instructions. Start by checking those voltages!